Short‐term storage of sperm in common carp from laboratory research to commercial production—A review - Nururshopa Eskander Shazada; Sayyed Mohammad Hadi Alavi; Mohammad Abdul Momin Siddique; Yu Cheng; Songpei Zhang; Marek Rodina; Martin Kocour; Otomar Linhart (Reviews in Aquaculture, 2024)
Short‐term storage of fish sperm is a simple and cost‐effective process in fishery research from basic to applied perspectives. It has been used to elucidate and evaluate gamete biology and quality, perform in vitro fertilization, develop sperm cryopreservation. Sperm short‐term storage is used in selective breeding, hatchery production and advanced molecular investigations such as disease detection of commercial species in aquaculture as well as biological conservation of threatened or endangered fishes. Several studies have demonstrated that the quality of common carp Cyprinus carpio sperm can be influenced by their health, age, nutritional status, the dose of administered hormone and environmental factors. When sperm is stored for short time, spermatozoa motility and viability as key determinants of fertility affected by storage parameters including the composition of natural seminal plasma, duration of exposure, temperature, dilution ratio if the extender is used, and additives in addition to the factors that affect sperm quality such as the age of male and spawning period. This is due to damage to the integrity of the plasma membrane, production of reactive oxygen species (ROS) causing oxidative stress and epigenetic modification. This review highlights and investigates the recent data regarding worldwide aquaculture production, short‐term storage of common carp sperm and the effects of storage on spermatozoa function with consideration to factors that affect sperm quality during storage. It also highlights the knowledge gap that must be filled in the future for designing methods from laboratory into practical applications of short‐term storage in the breeding program of common carp.

Recent advances in acoustic technology for aquaculture: A review - Daoliang Li; Zhuangzhuang Du; Qi Wang; Jun Wang; Ling Du (Reviews in Aquaculture, 2024)
Acoustic technology has great application prospects in aquaculture. In particular, two indispensable, critical technologies for the future aquaculture industry are multi‐sensor acquisition that can achieve multi‐scale information fusion, collection and establishment of a global acoustic fish database and highly developed deep learning intelligent algorithms that can establish a correlation mechanism between fish acoustic and behaviour characteristics. Acoustic technology offers remarkable advantages in large and turbid water bodies for studying spatial and temporal distribution patterns of aquatic organism populations, developing on‐demand feeding systems and estimating biomass. This article reviews the development of acoustic technology and its application in aquaculture over the last 30 years. It further analyses, in detail, the advantages and disadvantages of acoustic technology in evaluating aquatic organism biomass and morphological and physical indicators, aquatic organism behaviour and welfare improvement. Challenges of acoustic technology in acquiring dynamic target data accurately, building a global acoustic fish database and establishing connections between fish behaviour and acoustic characteristics are also discussed. In brief, this article aims to help researchers and practitioners better understand the current state‐of‐the‐art acoustic technologies, which can provide strong support for smart aquaculture applications.

Fate and effects of fish farm organic waste in marine systems: Advances in understanding using biochemical approaches with implications for environmental management - Deanna M. Elvines; Catriona K. MacLeod; Donald. J. Ross; Grant A. Hopkins; Camille A. White (Reviews in Aquaculture, 2024)
Particulate waste from open‐cage fish farms in marine systems can cause organic enrichment of seabed habitats and enter the food web through consumption by wild organisms, with potential for broader ecosystem changes. Effects on biogeochemistry and benthic ecology are reasonably well understood in inshore, sheltered and soft sediment systems. However, food web effects and interactions with epifauna and larger consumers is less well understood, as is the fate of these discharges in more dynamic coastal areas with complex hydrodynamic regimes. Expected expansion of the aquaculture industry globally includes farming new areas that are more environmentally dynamic and biodiverse, with potentially sensitive habitats. Therefore, the aim of this review was to examine how biochemical tools can assist in identifying and managing impacts. Biochemical tools such as bulk stable isotopes and fatty acids can reliably trace the fate of fish waste in the environment and the food web, and have advanced our understanding of waste dispersal, as well as providing greater insights into biological interactions with fish wastes. This includes elucidating trophic subsidies to wild organisms, candidate species for co‐culture and waste assimilation mechanisms in native communities. Ultimately, biochemical tools can support improved environmental management, by helping to identify the zone of influence for spatial planning, providing additional ‘forensic’ evidence for farm‐related change, and by identifying potential risks to high‐value species and habitats. In this way, they can inform targeted research to link fish waste inputs meaningfully to potential ecosystem changes to better understand the consequences to support sustainable industry expansion.

Electrochemical applications in RAS : A review - Raz Ben‐Asher; Youri Gendel; Ori Lahav (Reviews in Aquaculture, 2024)
Electrochemical water treatment for recirculating aquaculture systems (RAS) is a promising approach for replacing the biological water treatment methods and establishing a new RAS generation with improved cost‐effectiveness, lower environmental footprint, and no start‐up periods. On top of ammonia oxidation directly into N 2(g) , electrochemical oxidation results in effective disinfection, and in the removal of organic matter, including specific organic constituents such as off‐flavour agents. The paper provides an overview of incentives for the implementation of electrochemical methods in RAS. It covers the electrochemical principles relevant to aquaculture applications, the effects of physical and chemical parameters, as well as design considerations. In addition, the research performed to date for integrating electrochemical methods in RAS operation is reviewed and the variety of designs and operational configurations described. The electrochemical water treatment is perceived beneficial over biological water treatment especially in cold saline‐seawater aquaculture (e.g., Atlantic salmon), where large nitrification reactors are required and the large water consumption for purging processes can be curtailed. It is also beneficial for the culturing of nitrate‐sensitive species (e.g., L. vannamei ). The paper points out the gaps to be overcome for allowing commercial breakthroughs based on electrochemical water treatment, including the need for expanding the practice and improving engineering practices by operating pilot systems for growing fish at both small and large scales; adjusting of electrochemical cell designs for reducing both capital and operational costs; developing full‐proof malfunction‐free dechlorination strategies, and evaluating and optimizing the disinfection abilities for inactivating typical pathogens in aquaculture.

A meta‐analysis of aquaculture technical efficiency studies - Narimah Samat; Kim Huat Goh; Kok Fong See; Rabiatul Adawiyah Ibrahim; Ngai Weng Chan; Mou Leong Tan; Lai Kuan Lee; Ta Wee Seow; Muhammad Azizan Sabjan (Reviews in Aquaculture, 2024)
As the world population grows, the aquaculture sector faces challenges in the use of production systems to ensure the adequacy of the food supply. Technical efficiency analysis has been shown to be useful for improving resource management and production. This study provides a literature update and uses meta‐regression analysis to examine the variations in aquaculture mean technical efficiency (MTE) scores based on 101 studies published from 1998 to 2023. The findings show that studies with larger model dimensions, different output measures, an input‐oriented model specification and that analyse the exogenous variables of efficiency scores, freshwater aquaculture, and European data produce a narrower variance in MTE scores. In contrast, studies that use panel data and nonparametric data envelopment analysis (DEA) generate wider variance in MTE scores. As a result of these investigations, the findings suggest the importance of selecting appropriate variables and sample sizes for efficiency estimates. Robustness checks of efficiency scores from the DEA and stochastic frontier analysis (SFA) approaches are recommended for future studies. Different policies and regulations should be implemented in different countries and across different farming systems.

The flesh texture of teleost fish: Characteristics and interventional strategies - Zhe Wang; Fang Qiao; Wen‐Bing Zhang; Giuliana Parisi; Zhen‐Yu Du; Mei‐Ling Zhang (Reviews in Aquaculture, 2024)
With the growing demand of consumers for high‐quality aquatic products, controlling the harvest quality of farmed fish is becoming increasingly important in aquaculture industry. The texture is a sensory property that covers a group of attributes, such as firmness, tenderness, chewiness, adhesiveness, resilience, etc., which greatly determine consumers' perception and satisfaction for flesh products. Regarding texture quality, extensive research has been conducted in recent decades based on its related theories, influencing factors, and intervention strategies. However, the information available is largely scattered and disjointed. Essentially, flesh texture is mainly determined by the collective contribution of three major muscle components: muscle fibres, intramuscular connective tissue, and intramuscular fat. Therefore, changing these components in living animals through nutritional and management factors has the potential to modulate texture quality. Here, we briefly introduced the features and development of the three muscle components mentioned above, particularly their potential contributions to texture quality of fish flesh. Exciting promises to manipulate flesh texture through dietary intervention, feed restriction, and exercise training were also discussed. To ensure their applications in large‐scale aquaculture facilities, specific considerations of these regimens should be incorporated in experimental design parameters, including the species and age of fish, research system, experiment duration, and exercise intensity. Finally, the existing challenges and limitations of fish texture studies were presented, along with some viewpoints about current work and future directions of this field.

Utilization of functional feed additives to produce cost‐effective, ecofriendly aquafeeds high in plant‐based ingredients - Md. Sakhawat Hossain; Brian C. Small; Vikas Kumar; Ronald Hardy (Reviews in Aquaculture, 2024)
Fishmeals (FM) are the most superior protein sources in aquafeed. World‐wide growing demand and limited supply of FM limit its use as sole protein sources in aquafeed and force fish nutritionists to develop alternate protein‐based aquafeeds. However, increasing alternate proteins over a certain percentage reduces fish performance. Many attempts have been made (viz., manipulation of processing technology of feed ingredients and feed formulations, supplementation strategy) to overcome the negative effects of increasing alternative protein inclusion in aquafeeds. Among them, supplementation of functional feed additives (FuFAs) has received promising attention. Recently, several FuFA (nucleotides, organic acid, probiotics, prebiotics, and certain amino acids) have been administrated in alternative protein‐based aquafeeds and demonstrate increased efficiency of alternative protein utilization along with improved fish growth and health performances. However, numerous gaps remain in existing knowledge about the administration of exogenous FuFA in alternative protein‐based aquafeeds, including the effects on digestion, age/size‐related responses, species variations, absorption, metabolism, and influences on physiological responses. Application of biochemical and molecular technologies is important to better understand the underlying mechanisms of FuFA functions in alternate protein‐based aquafeed to improve fish and shrimp performance. Efforts are also needed by researchers and industrialists regarding production technologies to reduce functional feed supplement costs. Moreover, in‐depth research knowledge is needed considering the use of functional feeds to combat fish diseases and reduce dependence on antibiotics and chemical therapeutants, thereby making aquaculture more eco‐friendly.

Aquaponics nomenclature matters: It is about principles and technologies and not as much about coupling - Harry W. Palm; Ulrich Knaus; Benz Kotzen (Reviews in Aquaculture, 2024)
The food production system ‘ aquaponics ’ has moved a long way from its inceptions in the 1970s and 1980s. This paper suggests that it is the principle of aquaponics that should define what aquaponics is and then the rest follows according to systems and technologies. This paper supports the Palm et al. ( Aquac Int . 2018;26(3):813–42) position of having a nutrient supply threshold (>50%) from the feed via the aquatic organisms to the plants. We test the most recent alternative definitions (e.g. Baganz et al. Rev Aquac . 2021;14:252–64) that overcomplicate existing definitions and nomenclature. Any new definition needs to be referential to existing terms and properly tested. This paper does exactly that, concluding that several recent changes by Baganz et al. ( Rev Aquac . 2021;14:252–64) are not needed. We also debate that the key principle behind aquaponics is ‘ all about coupling ’. Whilst coupling is an important aspect, existing technologies and those that will emerge are far more complex. Finally, this paper highlights the idiosyncrasies in the term aquaponics and we suggest an alternative term ‘ aquaorganoponics ’, which in essence better describes the principles of aquaponics ( s.s. ) which transfers natural organic compounds combined with microbes in water from the aquaculture unit to the plants.

Spanish abstracts (Reviews in Aquaculture, 2024)

Offshore aquaculture in China - Lina Long; Huang Liu; Mingchao Cui; Chenglin Zhang; Chong Liu (Reviews in Aquaculture, 2024)
The mariculture industry is planning to move offshore due to the decline of China's inshore fishery resources, the deterioration of the water environment, inefficient industrial structure and other influencing factors. This article first analyses the imbalance between supply and demand of aquatic products, the development space of offshore aquaculture and the supporting policies, thereby concluding that China has significant potential to develop offshore aquaculture. Subsequently, the development status of offshore aquaculture in China is examined. The research progress of China's offshore aquaculture facilities, marine hydrology, environmental carrying capacity, aquaculture technology and the status of aquaculture operation equipment are also summarized. Furthermore, the problems existing in the development of offshore aquaculture are pointed out. On this basis, future development ideas for China's offshore aquaculture can be planned in terms of sea area layout, optimized and improved seed production systems, and research and development of offshore aquaculture technology and pellet feed. The relationship between the development of offshore aquaculture and ecological protection should be coordinated. Additionally, an energy security system can be built based on clean energy, and the development of related industries can be driven through the complementary industrial division of labour. The present work aims to provide a reference for promoting the development of offshore aquaculture in China.

Regulation of lipid metabolism by gut microbiota in aquatic animals - Shangong Wu; Meijing Pan; Ziye Zan; Ivan Jakovlić; Weishan Zhao; Hong Zou; Einar Ringø; Guitang Wang (Reviews in Aquaculture, 2024)
Lipids are an essential component of living beings and an important group of nutrients. As the gut microbiota plays important roles in the intestinal absorption and extraintestinal metabolism of dietary lipids, the current review addresses the recent progress regarding the interactions between the gut microbiota and lipid metabolism in aquatic animals, with a focus on fish. We discuss in detail how dietary lipid sources and content affect the composition of the gut microbiome and the mechanism by which the gut microbiota affects the lipid metabolism of the host. This interaction is largely mediated via microbial lipases, short‐chain fatty acids and the gut‐liver axis. The latter refers to the metabolism of biliary salts and acids, the regulation of their synthesis by gut microbes and their impact on the lipid metabolism. Finally, we briefly discuss how probiotic supplementation modulates the host's microbiome, and how probiotics have a beneficial effect on health and welfare of farmed aquatic animals. Although the influence of intestinal microbiota on lipid metabolism has been explored before, further research is needed to profoundly investigate the molecular mechanisms by which microbial metabolites (SCFAs and bile acids) induce lipid metabolism.

Status of conventional and molecular breeding of salinity‐tolerant tilapia - G. H. Yue; K. Y. Ma; J. H. Xia (Reviews in Aquaculture, 2024)
Aquaculture is an important sector for ensuring global food security. Due to the scarcity of freshwater available for expanding aquaculture, the development of omnivorous fish species and varieties that can tolerate high salinity will enhance fish production. Some tilapia species are good candidates for aquaculture in brackish and seawater because they can grow in high salinity. Among tilapia species, Oreochromis mossambicus , Oreochromis aureus , Oreochromis spilurus , Oreochromis urolepis hornorum , Sarotherodon galilaeus and Coptodon zillii are the most salinity‐tolerant. Hybrids derived from salinity‐tolerant tilapia species are tolerant to a certain level of salinity. They have been used in aquaculture production in brackish water and full seawater. Conventional selective breeding has been applied to increase the growth rate of salinity‐tolerant tilapias. However, their growth rate is lower than that of the freshwater Oreochromis niloticus . Recently, many genomic resources and tools have been developed for salinity‐tolerant tilapia. Quantitative trait locus (QTL) mapping and genome‐wide association studies (GWAS) for important economic traits, including salinity tolerance and other desired traits, have been carried out and applied in molecular breeding for superior salinity‐tolerant tilapia lines. In this review, we systematically analysed tilapia species that can be cultured in brackish and saltwater. We summarized previous works in conventional breeding and molecular breeding for salinity‐tolerant tilapia. We pointed out a few known and potential challenges in the selective breeding and culture of salinity‐tolerant tilapia. Due to the rapid advances in molecular and other disruptive technologies, we are optimistic that novel breeding approaches will significantly increase the production salinity‐tolerant tilapia.

A review on the application of chicken immunoglobulin Y in aquaculture - Linpeng Zhang; Li Lin; Zhendong Qin (Reviews in Aquaculture, 2024)
The widespread use of antimicrobial drugs in aquaculture has led to antibiotic residues in aquatic animals. Food safety problems caused by the misuse of antibiotics and antibiotic residues have caused widespread global concern. Consequently, there is an urgent need to develop an alternative to antibiotics for use in aquaculture. Immunoglobulin Y (IgY) has attracted significant attention over recent years because it is readily available, simple to prepare, effective in inhibiting pathogenic microorganisms, free from environmental contamination and free from other toxic side effects. In this paper, we review the research progress relating to the basic structure, physicochemical properties and mechanism of action of IgY. We also highlight the applications of IgY in the control of aquatic animal disease, immunological diagnosis and the preservation of aquaculture products, thus providing a reference for future research and the wider application of IgY in aquaculture.

Retrospect of fish meal substitution in Pacific white shrimp ( Litopenaeus vannamei ) feed: Alternatives, limitations and future prospects - Yongkang Chen; Anisa Mitra; Samad Rahimnejad; Shuyan Chi; Vikas Kumar; Beiping Tan; Jin Niu; Shiwei Xie (Reviews in Aquaculture, 2024)
Pacific white shrimp ( Litopenaeus vannamei ), the most cultured crustacean in the world, has become one of the key species in the international aquatic trade accounting for 11.96% of the total aquaculture production value in 2020. The development of the aquafeed industry, especially the large‐scale use of fish meal (FM) and fish oil, contributed to promoting the expansion of shrimp production. However, the supply of FM has fluctuated at about 5 million tons per year affected by the El Nino during the last decades. This finite supply in combination with continued demand contributes to high prices, prompting the development and use of alternative protein sources. This review contributes to the development of appropriate FM replacement strategies in shrimp feed and summarises the status of research on alternative protein sources, including plant, animal and single‐cell proteins in commercial feeds for Pacific white shrimp. Furthermore, several key aspects of nutritional balances were mentioned including amino acid profiles, fatty acid nutrients and trace elements in low FM diets as well as some easily overlooked concepts that deserve attention such as epigenetics, feed processing characteristics, animal growth stages, and shrimp species improvement. Also, the prospects of future research are proposed including the application of advanced technologies (16S rRNA sequencing, transcriptomics, proteomics and metabolomics), developments in the new feed additives, along with the optimisation of new protein sources and the establishment of a precise nutritional programming for shrimp.

Monogenean Sparicotyle chrysophrii : The major pathogen of the Mediterranean gilthead seabream aquaculture - Ivona Mladineo; Donatella Volpatti; Paola Beraldo; George Rigos; Pantelis Katharios; Francesc Padros (Reviews in Aquaculture, 2024)
Following the intensification of the Mediterranean aquaculture over the years, Sparicotyle (syn. Microcotyle ) chrysophrii (van Beneden and Hesse, 1863; Microcotylidae, Monogenea) became one of the most pathogenic ectoparasites for the gilthead seabream ( Sparus aurata L.) aquaculture. It has demonstrated a remarkable versatility to expand over its known host range, accomplish an efficient transfer between the wild and farmed sparid populations over wide geographic areas, and establish itself as the most detrimental gilthead seabream pathogen. Even though the incidence of S. chrysophrii is closely monitored in marine aquaculture system throughout the Mediterranean, there is a general lack of recent and publicly available data on its epidemiology. Being considered as a parasite whose proliferation is expected to increase under global warming conditions, such lack of data additionally humpers the implementation of integrated pest management strategy at national and Mediterranean level. While EU scientific initiatives greatly contributed to our understanding of S. chrysophrii biology, ecology and sparicotylosis treatment and pathogenesis, there is more ahead to elucidate about the mitigation of the diseases, particularly towards the development of genomic selection breeding programs of parasite‐resilient gilthead seabream, omic‐based screening of novel drug targets and reversed vaccinology.

Structure, function and immune evasion strategies of aquareoviruses, with focus on grass carp reovirus - Peng Wei Li; Jie Zhang; Ming Xian Chang (Reviews in Aquaculture, 2024)
Aquareoviruses (AqRVs) can infect various wild or cultured bony fishes with serious muscle and viscera haemorrhage syndrome and have caused severe economic losses worldwide. Accumulating evidences have revealed the functions of viral proteins of AqRVs in RNA transcription, virion assembly, cell attachment and/or viral replication. In addition, structural information and transcription mechanism of AqRVs have been in‐depth studied through cryo‐electron microscopy combined with three‐dimensional image reconstruction. Although far from enough, structural and functional studies of AqRVs provide substantial insights into how viral proteins coordinate the replication of AqRVs and escape the host immune response. Grass carp reovirus (GCRV) is the most pathogenic AqRV isolated from aquatic animals. The completion of GCRV lifecycle requires the participation of host proteins. So far, many host factors involved in the entry and replication of GCRV have been identified. Based on the function of viral proteins and the viral lifecycle, many vaccines and antiviral agents have been developed to prevent the replication and infection of GCRV. This review summarises the structural characteristics and the composition of core proteins of AqRVs, as well as synergistic mechanisms of structural proteins on genome transcription and virus entry of AqRVs. In addition, the review highlights our current knowledge for the infection and replication, functions of non‐structural proteins, immune escape mechanisms, as well as the vaccines and antiviral agents of AqRVs, especially for GCRV. A better understanding of structure, function and immune evasion strategies of AqRVs will offer new targets for prevention and control of AqRVs in aquaculture.

Guests or pests? Eirenid hydroids living on the soft tissue of bivalves - Cristina Di Camillo; Camilla Roveta; Torcuato Pulido Mantas; Cinzia Gravili; Carlo Cerrano; Barbara Calcinai; Martina Coppari; Chiara Gregorin; Teo Marrocco; Agnese Riccardi; Stefania Puce (Reviews in Aquaculture, 2024)
Both wild and reared bivalves can host hydroids from the Eirenidae family which settle on the soft body parts of their host. Thousands of hydroids have been observed on a single bivalve, and often have severe detrimental effects on the host. However, this relationship has received little attention in aquaculture research, which is probably due to a lack of baseline data. An extensive review was conducted (i) to show the current level of knowledge on the association between eirenids and bivalves, providing a benchmark for future research; (ii) to detect a critical combination of biotic/abiotic factors that could switch the relationship from commensalism to infestation and (iii) to identify research priorities for future studies. Seventy scientific papers were screened to provide ecological information useful in understanding the hydroid‐host‐environment interactions and to show the global spatial and bathymetric distribution of the relationship. Although the main parameters influencing the hydroid abundance were identified, it was challenging to collate information from such heterogeneous data sources. A standardized method for data collection is proposed to obtain more robust and comparable data on the association. The most relevant and unstudied issue is the potential physiological and qualitative changes that could occur in infested bivalves. Monitoring the association could provide data needed to prevent or to control hyper‐proliferation of the symbionts and to detect eventual synergistic effects with climate change. This could be fundamental for species living in areas particularly prone to climate regime shifts, such as semi‐enclosed basins and estuarine habitats.

The antiviral activity of currently used medicinal plants in aquaculture and structure–activity relationship of their active ingredients - Yang Hu; Xu Zhang; Li‐peng Shan; Lei Liu; Jiong Chen (Reviews in Aquaculture, 2024)
Aquaculture is an important source of high‐quality protein and plays a crucial role in ensuring global food security. However, viral diseases have caused significant damage to aquaculture production, making it necessary to develop effective measures to treat them. Although drugs are commonly used to treat viral diseases, recent studies have shown that crude extracts of medicinal plants and their active ingredients have potential applications in the treatment of aquatic viral diseases. Furthermore, natural small molecule compounds from herbs could be used as lead compounds to develop more potent anti‐aquatic virus derivatives. As such, there is an urgent need to develop and apply drugs for the treatment of viral disease outbreaks in aquaculture. In this review, we summarize previous studies on the efficacy of different agents used as antiviral drugs in aquaculture, with a focus on their protective effects. Additionally, we highlight the potential of active natural compounds isolated from medicinal plants, which could serve as lead compounds for developing aquatic‐specific drugs. However, the relationship between the structure of a compound and its antiviral activity in aquaculture has not been clearly elucidated, posing a challenge for further drug optimisation. Therefore, this study also analyses the structure–activity relationship of several reported lead compounds and their derivatives in aquaculture, providing a reference for subsequent drug development efforts.

Enhancing aquaculture disease resistance: Antimicrobial peptides and gene editing - Jinhai Wang; Yu Cheng (Reviews in Aquaculture, 2024)
Previous studies have demonstrated that CRISPR/Cas9‐mediated genome editing and transgenesis by integrating vector‐engineered antimicrobial peptide genes (AMGs) are effective to modulate the fish's innate immune system. To generalise the knowledge of AMG application in aquaculture, we recruited 544 data entries from a pool of empirical studies, which included 23 studies (two unpublished from our team) spanning 12 diseases. We systematically re‐processed and re‐analysed these data by harnessing a cross‐disease meta‐analysis. On aggregate, AMG‐genetic engineering aimed at enhancing disease resistance was shown to decrease the number of colony‐forming units of bacteria from fish tissues, increase post‐infection survival rates, and alter the expression of AMGs and immune‐related genes. Further, AMG pathogen‐combating activity was triggered within 2 h after infection and lasted 48 h. The overexpression of AMGs was highest in the spleen and skin, followed by the kidney and liver during this period. Typically, regardless of the type of AMGs, the synergistic expression of AMGs with IL ‐ 10 , IKβ , TGFβ , C3b and TLR genes in AMG‐integrated fish contributed to activating inflammatory/immune responses against pathogens. Our findings revealed that the efficiency of transgenic AMGs against pathogens was fish‐, pathogen‐ and AMG‐specific. Compared to bacteria, transgenic AMGs were less inhibitory to viruses and parasites. In addition, innovative CRISPR/Cas9‐based transgenesis enabling the site‐directed knock‐in of foreign genes at multiple loci was assessed for the enhancement of disease resistance in combination with other favourable fish‐production traits, including fast growth, sterility and enriched fatty‐acid content. Altogether, our findings indicated that AMGs as transgenes have substantial promise to modulate the fish's innate immune system and enhance disease resistance.

Chinese perspectives on aquaculture careers: Insights from post‐graduate students and early career researchers - Caixia Wu; Changxu Sui; Chenxiang Zhang; Manxi Zhao; Ting Xu; Zhijie Shi; Yueru Li; Giovanni M. Turchini (Reviews in Aquaculture, 2024)

The role of pattern recognition receptors in crustacean innate immunity - Bharat Bhusan Patnaik; Snigdha Baliarsingh; Arup Sarkar; A. S. Sahul Hameed; Yong Seok Lee; Yong Hun Jo; Yeon Soo Han; Jyotirmaya Mohanty (Reviews in Aquaculture, 2024)
Crustacean species are among the most valued seafood with socioeconomic and ecological implications in the global fisheries sector. Microbial infections to the farming stock due to continued expansion and aquaculture puts global crustacean production at risk. Understanding and reviewing the complex innate immune system of crustaceans would be pivotal in formulating informed decisions for the control and management of epidemic diseases, thus making the global crustacean aquaculture industry sustainable. Under the purview of innate immunity in crustaceans, pattern recognition receptors (PRRs) represent the sensors capable of discriminating non‐self pathogenic modules and invoking the activation of immune responses. The immunity to infections can be manifested at cellular (via phagocytosis, apoptosis, nodulation and encapsulation) and humoral (effected by prophenoloxidase cascade, lectins, antimicrobial proteins) levels leading to the elimination of pathogens or subversion of the pathogenic implications. In this review, we discuss the participatory role of 12 types of PRRs identified from crustacean species with an exhaustive focus on structural and functional specificities in binding to pathogens and possible execution of the immune activity. Moreover, we have elaborated on the PRRs‐associated or possible signalling cascades (Toll‐NFκB, IMD‐NFκB and JAK‐STAT) in crustacean species that could bridge our understanding of the resistance or susceptibility of the host to varied pathogenic infections thus providing clues to the regulatory mechanisms involved in pathogenesis of infectious diseases and mechanisms of immunity.

Spawning induction for Latin American fishes - Alejandro S. Mechaly; Sergio R. Batlouni; Mariano Elisio; Eduardo A. Sanches; Jonathan Chacon Guzmán; Minerva Maldonado García; Adriana Rodríguez‐Forero; Paula Vissio; Elvira Fatsini; Jesús Núñez; Neil Duncan (Reviews in Aquaculture, 2024)
Aquaculture offers solutions to meet the growing global demand for fish, and reports from the UN‐FAO indicate that aquaculture production in Latin America (LA) has grown at rates above the world average in recent years. One of the major constraints in the diversification of LA aquaculture is the control of reproduction in several popular native fish species for which difficulties in captive propagation have not yet been sufficiently overcome. This article reviews the use of hormone treatments to promote reproduction in females of these native fish species. LA has played a key role in the history of development of hormone administration, including the first hormonally induced spawning. That contribution is included in a historical overview of the discovery of the major hormones used in fish culture. The review provides a summary of difficulties to propagate females of various native fishes and the effects of administering hormones to enhance reproduction. Induced spawning of certain freshwater species was mainly achieved with pituitary extracts or human chorionic gonadotropin (hCG), although gonadotropin‐releasing hormone analogues (GnRHa) treatments are being researched, and successful studies suggest that low doses may be more effective. Research on new and emerging aquaculture species has applied both gonadotropins (Gths) and GnRHa‐based treatments, and GnRHa treatments have shown potential for marine species. However, native marine species new to aquaculture have also been conditioned to spawn spontaneously without hormones. Finally, we proposed future lines of research to examine reproductive strategies and GnRHa‐based hormone treatments to improve reproductive control for economically important fish species of LA.

Arabic Abstracts (Reviews in Aquaculture, 2024)

Diatom‐assisted aquaculture: Paving the way towards sustainable economy - Raya Bhattacharjya; Thomas Kiran Marella; Munil Kumar; Vikas Kumar; Archana Tiwari (Reviews in Aquaculture, 2024)
With decreasing world oceans fish stock there is rapid increase in aquaculture production. To meet this demand, there is an urgent need to improve existing aquaculture technologies and make the system more sustainable and economically feasible. Diatoms are unicellular protists that are present ubiquitously in freshwater and marine habitats and are responsible for 40% of marine and 20% of net global primary productivity. They are the most preferred microalgae for production of live feeds in mariculture due to their suitable size, easy digestibility, and optimum nutritional content. Diatoms biosynthesize a range of bioactive compounds like lipids, polysaccharides, proteins, pigments, and vitamins which can both promote the health and survival of aquatic species like fishes, bivalves, and shrimps. As the main prerequisite to attain sustainability is to reduce pollutants from aquaculture wastewater, diatoms have long been employed for remediating and utilizing the eutrophic nutrients as a growth supplement which otherwise might be detrimental to aquaculture species. Though many recent studies have highlighted the significance of diatoms in aquaculture, its dual contribution in maintaining the nutritional content of the feed as well as in improving the water quality should be coupled with its unique mechanisms and adaptability. Thus, the current review addresses the bottlenecks in aquaculture industry and the prospects of implementing diatom‐based bioremediation and biomass valorization for the production of live feeds with the hindsight of establishing circular bioeconomy.

Expanded utilisation of microalgae in global aquafeeds - Muhammad A. B. Siddik; Mette Sørensen; S. M. Majharul Islam; Newton Saha; Md Arifur Rahman; David S. Francis (Reviews in Aquaculture, 2024)
Utilising novel ingredients in aquafeeds is necessary for the continued expansion and intensification of aquaculture production. Microalgae are utilised widely in aquaculture for a variety of purposes; as live feed for fish and shellfish larvae and juveniles, for the production of algae‐based meals and oils to replace marine derived raw materials in aquafeeds, and for the production of astaxanthin, the carotenoid that gives salmon flesh its characteristic reddish colour. Notably, long‐chain polyunsaturated fatty acids, amino acids, proteins, fibres, antioxidant pigments, vitamins and minerals are among the compounds in microalgae with great biological value. A growing collection of experimental data has demonstrated that these substances are crucial for increasing larval survival and enhancing the growth and well‐being of fish and shellfish. In this review, the processing of microalgae utilised as aquafeed ingredient, the health promoting compounds in microalgae and their role in growth, immunity and disease resistance of fish and shellfish are described and discussed. Simultaneously, major hurdles in the commercial use of microalgae in aquafeed, and future research and development perspectives are all critically discussed.

Portuguese‐Brazilian abstracts (Reviews in Aquaculture, 2024)

Issue Information (Reviews in Aquaculture, 2024)

A systematic review of drying in aquatic products - Junpeng Zeng; Yu Song; Peixu Cong; Yunrui Cao; Jie Xu; Changhu Xue (Reviews in Aquaculture, 2024)
Drying is an essential method for the process and storage of aquatic products. With the removal of water, the occurrence of oxidation, hydrolysis and browning reaction also accompanies it. This article reviews the applications of emerging drying methods in aquatic products, emphasising high‐quality drying. In addition, it summarises the effects of the drying process on the quality of aquatic products, including appearance, nutritional components, flavour and microorganisms. Especially, non‐destructively monitoring technologies are introduced and discussed, including near‐infrared spectroscopy, Raman spectroscopy, hyperspectral imaging, low‐field nuclear magnetic resonance and computer vision system, which are applied to detect and predict the quality of aquatic products. A comprehensive review of recent advances in the research of the drying process of aquatic products is presented, and some perspectives are made for future research.

Chinese abstracts (Reviews in Aquaculture, 2024)

The influences of nitrogen and phosphorus availability on periphytic algae in eutrophic experimental mesocosm - Yuzhi Song; Jing Guo; Jinqi Wang (New Zealand Journal of Marine and Freshwater Research, 2023)
To investigate the influence of nitrogen (N) and phosphorus (P) availability on the periphytic algal biomass and assemblage composition (by pigment analysis) in the eutrophic lake, natural littoral intact sediment cores in a subtropical eutrophic lake (Lake Taihu) were collected, and subjected to three levels of water N and P loading (N‐P [mg. L −1 ]: 1.5, 0.075; 2.5, 0.125; 3.5, 0.175) in the tanks, eighteen artificial substances (glass slides) were fixed at three water depths (1, 17, and 33 cm above the surface sediment) for development of periphytic algae in each tank, respectively. The results showed that the biomass of periphytic algae on artificial substance was significantly enhanced with increasing N and P levels in water column and water depth ( p

The first record of Australian flatback mangrove goby Mugilogobius platynotus (Günther 1861) (Gobiidae; Tridentigerinae) from New Zealand - Clive D. Roberts; Andrew L. Stewart (New Zealand Journal of Marine and Freshwater Research, 2023)
The eastern Australian flatback mangrove goby Mugilogobius platynotus (Günther 1861) is recorded for the first time from Aotearoa, New Zealand. Three voucher specimens (two males and one female) were collected using fish traps submerged in tidal drains of a saltmarsh wetland edged by mangroves adjacent to Ngunguru River, Northland. Key characters for identification: the colour of freshly thawed specimens, meristic counts, and morphometric measurements are presented and compared with the same characters described by Larson (2001) for all Mugilogobius . We discuss this major range extension from its natural Australian distribution, concluding it is an adventive species, probably carried across the Tasman Sea into New Zealand waters by shipping, not ocean currents. Our analysis of goby species recorded from northern New Zealand mainland waters concludes seven (86%) are probably adventive and introduced from Australia. We recommend a further survey of mangrove and saltmarsh estuary habitats to discover if this new goby has established a breeding population and is expanding its current limited distribution within northern New Zealand.

First observations and early life‐history aspects of lake rearing galaxiid larvae in the lower Waikato River Basin, New Zealand - Bruno O. David; Matt Jarvis; Deniz Özkundakci; Josh Smith; Ian C. Duggan; Sung Soo Koh; Jason Augspurger; Tania M. King (New Zealand Journal of Marine and Freshwater Research, 2023)
Larval behaviour for many of New Zealand's diadromous freshwater fish is inadequately described. Diadromy for many amphidromous species is not obligatory however, and where conditions are suitable, freshwater larval rearing may be facilitated. Where this occurs in lakes, opportunities to document the composition and conditions supporting larval rearing exist. Boat trawling was undertaken across nine lowland lakes in the Lower Waikato over four consecutive winters with a focus on larval galaxiids. Galaxiid larvae were captured in surface water habitats in all but one lake, with banded kōkopu ( Galaxias fasciatus ) and giant kōkopu ( Galaxias argenteus ) the most common species detected. One lake, Lake Waahi, consistently resulted in the most galaxiid captures for effort expended. Analyses of larvae from this and other lakes indicated that two sizes predominated in catches and that larger, older larvae were predominantly G. fasciatus while smaller, younger larvae were predominantly G. argenteus . Stomach contents indicated that two non‐native zooplankton species predominated in the diet of larvae, the Holarctic daphnia, Daphnia galeata , and the Australian calanoid copepod Boeckella symmetrica . This study provides new information regarding the timing, movement and predicted recruitment of native fish species in this river basin that has important implications for lake and river management.

Diatom nutrient requirements change with lake nutrient limitation and enrichment in New Zealand dune lakes - Rose Gregersen; Kevin S. Simon (New Zealand Journal of Marine and Freshwater Research, 2023)
Nutrients are important determinants of diatom growth in lakes, and diatoms are considered reliable indicators of changing lake nutrient concentrations and eutrophication. However, diatom ecologies are not static, nor are they linked to single environmental variables, leading to imprecise diatom nutrient inferences. Anthropogenic nutrient enrichment is the principal issue facing New Zealand's lakes. Thus, knowledge of diatom responses to nutrients in New Zealand lakes will be important for understanding contemporary and past changes in nutrient availability. Using a nutrient amendment experiment and diatom communities from dune lakes, here we show that the response of specific diatom species is not universal among lakes and is partly determined by lake nutrient concentrations and limitation status. The response of focal diatom species to nutrient additions differed from previously reported nutrient requirements, and did not align with published, assigned trophic statuses. This study highlights that the response of diatoms to nutrient enrichment is context‐dependent, and that intraspecific generalisations of diatom ecologies between geographic locations or through time should be made with caution. To apply diatoms to making nutrient inferences, more work focusing on how physiochemical and biological factors influence diatom nutrient requirements is required.

Restoring the seagrass Zostera muelleri with transplants: small cores are as effective as larger plots - Fleur E. Matheson; Graeme Mackay; Crispin Middleton; Richard Griffiths; Ricky Eyre; Josh Smith; Ron Ovenden (New Zealand Journal of Marine and Freshwater Research, 2023)
Seagrass extent has declined globally, including in New Zealand. Following the success of an initial trial to transplant and re‐establish intertidal seagrass at a former site in Whangarei Harbour, a second trial was initiated. This trial aimed to restore seagrass at a more distant former site and tested the efficacy of transplant units ranging in size from small cores (5 or 9 × 0.01 m diameter cores placed within a 0.25 m 2 plot) to larger entire plots (0.25 m 2 or 0.5 m 2 ). Seagrass was transplanted in winter when plants were dormant. Plant cover of transplanted and donor plots and light climate at both sites were monitored over a period of four years. All but one of the 24 units survived, and the plants began to spread after 12–18 months to eventually develop patches ranging in size from 5 to 68 m 2 . Seagrass recolonised all donor plots completely within 10 months. Results show that small cores and larger plots can both be used successfully to transplant and restore populations of Zostera muelleri with no long‐lasting damage to donor meadows. However, use of small cores is recommended to minimise extractions and loss of transplanted material, and to simplify logistics.

Trophic ecology of the deep‐sea squid Moroteuthopsis ingens (Cephalopoda: Onychoteuthidae) from the Chatham Rise, Aotearoa New Zealand - Laura E. McBride; Heather E. Braid; Darren W. Stevens; Kathrin S. R. Bolstad (New Zealand Journal of Marine and Freshwater Research, 2023)
Cephalopods form important components of marine trophic systems worldwide, including those in the South Pacific. Moroteuthopsis ingens (Onychoteuthidae) is one of the most abundant deep–sea squids in the Aotearoa New Zealand region and is preyed upon by predators such as the sperm whale and orange roughy. However, despite the many publications on M. ingens ’ diet, knowledge on its feeding ecology remains limited. In this study, we analysed the prey of M. ingens from the Chatham Rise (an ecologically and economically important region east of Te Waipounamu/New Zealand's South Island) using DNA barcoding and otolith identification. Lanternfishes (Myctophidae) were the most frequently encountered prey item, but other teleost species, cephalopods and crustacean fragments were also found, indicating opportunistic and likely cannibalistic feeding behaviour. Five fish species (including a possibly undescribed species of Gymnoscopelus ) and Bathyteuthis abyssicola are reported as prey items of M. ingens for the first time. Moroteuthopsis ingens appears to be a component of several dynamic food chains and likely plays an important role in the transfer of carbon throughout marine environments in the Southern Hemisphere.

Range expansion of the invasive portunid crab Charybdis japonica in New Zealand - Kyle Hilliam; Ian D. Tuck (New Zealand Journal of Marine and Freshwater Research, 2023)
Charybdis japonica , a large invasive portunid, has been recorded in New Zealand since its detection in the Waitematā Harbour in 2000. In this study, the distribution, invasion history, abundance and population structure were investigated for C. japonica across the North Island of New Zealand. This was done using various distribution data available, trapping across several sites and interviews with commercial fishermen. Charybdis japonica was detected in the previously uninvaded Tauranga, Ohiwa, Hokianga, Manukau Harbours and Great Barrier Island. The rate of spread for C. japonica is continuous, with harbours or estuaries hundreds of kilometres apart having detections every two to three years. Population abundances reported by commercial fishermen constantly increased, with no signs of stabilisation or decrease. Catches were male‐biased, with female abundance varying seasonally. Several possible pathways and vectors may be responsible for this spread, including shipping and aquaculture, on top of dispersal of larvae by currents across the North Island. Further research is required to determine population sources, with findings providing important information for invasive species monitoring and management.

Tasman Sea high‐ and low‐ chlorophyll events, their links to marine heat waves, cool spells, and global teleconnections - Stephen M. Chiswell (New Zealand Journal of Marine and Freshwater Research, 2023)
Previous work has suggested that marine heat waves (MHW) and cool spells (MCS) in the Tasman Sea are responses to a stalling of an eastward propagating austral wavenumber‐4 atmospheric pressure wave. We investigate extrema in sea surface chlorophyll (SSC), defining high‐ and low‐chlorophyll events (HCE and LCE) analogous to MHW and MCS, but using Tasman‐Sea averaged SSC anomalies. From 2002 to 2020, there were 13 HCE and 10 LCE, with no indication of changes in frequency, duration, or intensity of events. HCE tend to occur when Tasman‐Sea averaged sea surface temperature is anomalously cool, and LCE tend to occur when Tasman‐Sea averaged surface temperature is anomalously warm, however, there is no direct relationship between temperature and chlorophyll extrema. Canonical HCE/LCE formed from the 2002 to 2020 events suggest that HCE/LCE are also driven by the austral wavenumber‐4 atmospheric wave. HCE occur during periods of low wind stress after a period of increased wind stress, whereas LCE may be a result of strong vertical mixing that mixes surface phytoplankton downwards. The implications of this work are that changes in Tasman Sea primary production in a future ocean will depend on any changes in the wavenumber‐4 atmospheric wave.

Characterisation of dissolved organic matter from temperate wetlands: field dynamics and photoreactivity changes driven by natural inputs and diagenesis along the hydroperiod - Patricia E. García; Carolina F. Mansilla Ferro; María C. Diéguez (New Zealand Journal of Marine and Freshwater Research, 2023)
Wetlands store large amounts of C in biomass, sediments and water. A major C fraction is in the dissolved organic matter (DOM) with multiple regulatory functions. Patagonian wetlands undergo changes in the water cycle due to climate warming and lower precipitation, causing shorter hydroperiods and reduced landscape connectivity with effects on C budgets. This study focuses on the optical characterisation of the DOM of an ephemeral wetland of North Patagonia. Along the hydroperiod the DOM showed optical signatures indicating terrestrial inputs, degradation and internal production. Dissolved organic carbon (DOC) concentration ranged between ∼4 and ∼9 mg L −1 . The DOM pool displayed high molecular weight/size and aromatic fingerprints. Humic components C1 (microbial and/or vegetation derived) and C2 (soil/sediment) prevailed in the DOM, whereas the non‐humic component C3 (from aquatic processes) increased from early spring. Experimental exposure to PAR + UVR produced slight changes in DOC and reduction in DOM molecular weight/size. The components showed distinctive photoreactivity/lability: C1 > C3 > C2. Along the hydroperiod the relative contribution of the humic vs. non‐humic components (C1 and C3) determined the reactivity/lability of the DOM. In Fantasma pond, the DOM pool fluctuates in response to hydrology and degradation processes, and the alternance between dry and flooded periods determines C dynamics.

Decadal stability in the distribution of bottlenose dolphins in Dusky Sound/Tamatea, New Zealand - Steph Bennington; Marta Guerra; David Johnston; Rohan Currey; Tom Brough; Chloe Corne; Dave Johnson; Shaun Henderson; Elisabeth Slooten; Steve Dawson; Will Rayment (New Zealand Journal of Marine and Freshwater Research, 2023)
Recreational use of wild spaces is increasingly popular, resulting in a burgeoning tourism industry. Such activities can degrade the environment and disrupt the behaviour and natural function of organisms. A small population of bottlenose dolphins ( Tursiops truncatus ) is resident in Dusky Sound, New Zealand, a fjord with increasing human use. Dolphins, as top predators, play an important role within ecosystems and are at risk of long‐term negative consequences from behavioural changes when exposed to high levels of vessel activity. A better understanding of the distribution of the dolphins in Dusky Sound would provide a framework for developing management within the fjord. Here we describe where dolphins were most frequently found, based on >40,000 km of photo‐ID survey effort conducted over 10 years. Kernel density estimation revealed two large core areas that remained consistent over the duration of this study. This information could be used to determine areas within Dusky Sound where human activities around dolphins could be managed to avoid anthropogenically driven detrimental impacts. We suggest the following: (1) establish dolphin protection zones, (2) create a marine mammal sanctuary, (3) extend marine reserve boundaries, and/or (4) lower catch limits for fish within the fjord boundaries.

First record of Chaetomorpha ligustica (Cladophoraceae, Cladophorales) smothering the seagrass Zostera muelleri in a New Zealand estuary - Iñigo Zabarte‐Maeztu; Roberta D'Archino; Fleur E. Matheson; Merilyn Manley‐Harris; Ian Hawes (New Zealand Journal of Marine and Freshwater Research, 2023)
The filamentous green alga Chaetomorpha ligustica (Cladophoraceae, Cladophorales) was recorded covering seagrass meadows at Pāuatahanui Inlet, New Zealand. Species of the genus Chaetomorpha are difficult to identify by their morphologically, and the identification of C. ligustica was confirmed by sequencing the 28S rRNA large subunit providing a high level of confidence in the species designation. In November 2019, we found C. ligustica intertwined with Ulva spp. forming dense, heavy and entangled structures. Here we report, for the first time, negative impacts of this species upon meadows of the New Zealand seagrass Zostera muelleri . We observed a significant loss of seagrass cover and evidence of anoxia under C. ligustica mats two weeks from the first sighting. Chaetomorpha ligustica can easily be misidentified in the field. This may lead to over‐ and under‐reporting of species, and we recommend the need for more careful identification of macroalgal blooms in the future and further research on growth requirements and origins of strains.

Not friends, just roommates: social organisation of two South American sea lion non‐breeding colonies - Gisela Vanina Giardino; María Agustina Mandiola; Julián Bastida; Joaquín Carlos Mario Gana; Ricardo Oscar Bastida; Diego Horacio Rodríguez (New Zealand Journal of Marine and Freshwater Research, 2023)
Groups of male South American sea lions ( Otaria flavescens ; SSLs) congregate in harbours on the northern coast of Argentina. These groups are very dynamic, with a high degree of habituation to human activities and the ability to colonise different types of artificial substrates, making them an interesting subject for understanding individual association patterns and spatio‐temporal variations in this species. In the present study, we recorded the associations between individual bleach‐marked SSLs in the harbours of Mar del Plata (PM) and Puerto Quequén (PQ) on four different substrate types during four non‐breeding seasons. We found that the association pattern differed between the harbours, with a well‐differentiated social structure being evident in PM but very little social differentiation occurring in PQ. The observed social structure in PM may have resulted from passive habitat preference rather than genuine social behaviour, as the association pattern disappeared when SSLs moved to sandy beaches within the harbour. Given that these colonies are must‐see tourist attractions but may have negative interactions with human activities, we recommend considering the association between SSLs and artificial habitats to design effective management strategies and reduce potential conflicts.

CSI – Cuttlefish Sepion Investigation: overview of cuttlebones found on Aotearoa New Zealand shores and analysis of predation and scavenging marks - Rodrigo B. Salvador; Amanda Reid; Lara D. Shepherd; Diana Macpherson; Alan J. D. Tennyson (New Zealand Journal of Marine and Freshwater Research, 2023)
Despite the absence of cuttlefish in Aotearoa New Zealand waters, cuttlebones and cuttlebone fragments have been reported and collected in the country since the early twentieth century. Not all could be reliably identified. As such, here we review all cuttlebone material collected from New Zealand shores available in natural history collections, as well as literature and online records. Species were identified, through morphological features and, for the first time, DNA barcoding, as: the Australian endemic Sepia apama Gray, 1849 (and possibly S. grahami A. Reid, 2001) and the widely distributed Indo‐Pacific S. latimanus Quoy & Gaimard, 1832. In addition, the predation/scavenging marks (praedichnia) left on the cuttlebones by other organisms are assigned to four major types and attributed to albatrosses, sharks, and dolphins. The successful extraction of DNA from cuttlebones has potential future applications, including the examination of type specimens, since species were described based only on cuttlebones.

Wastewater treatment plant effluents in New Zealand are a significant source of microplastics to the environment - Helena Ruffell; Olga Pantos; Grant Northcott; Sally Gaw (New Zealand Journal of Marine and Freshwater Research, 2023)
Wastewater treatment plants (WWTPs) have been identified as a source of microplastics, an emerging contaminant class of increasing concern, to the environment. Three WWTPs in the Canterbury region, New Zealand, were sampled bi‐monthly from winter (June) to summer (December), to assess the variability of the abundance, morphology and polymer type of microplastics present over time. Microplastics were isolated from effluent via wet‐sieving (300 μm and 1 mm) and wet peroxide oxidation (WPO) digest, and the polymer types determined using micro‐Fourier‐Transform Infrared Spectroscopy (μ‐FTIR). Confirmed microplastics were detected at an average concentration of 1.3 ± 0.6 particles/L in effluent, with fragments comprising 58% of all morphotypes. Dominant polymer types detected were polyester, polyethylene, and polypropylene (26%, 22%, and 15%, respectively). The results of this study were comparable with those reported in international studies. An estimated 2.4 × 10 5 microplastics enter the receiving coastal environment daily from the discharge of effluent from the three WWTPs studied. No trends in microplastic concentration, morphotype and polymer type were observed in effluent samples from each WWTP, suggesting a common and continual source of microplastics into WWTPs. Further sampling is required to identify the factors that determine the variability of microplastics in WWTP influents and effluents.

Accounting for diverse cultural values in freshwater management plans by using a transparent and collaborative decision support system based on multi‐criteria decision analysis - Simone Daniela Langhans; Marc Schallenberg (New Zealand Journal of Marine and Freshwater Research, 2023)
The inadequate success of decades‐long attempts to restore aquatic biodiversity casts doubt on the effectiveness of common top‐down driven approaches that focus on ecological and socio‐economic objectives alone. A way forward is engaging with the public with the aim of accounting for cultural values and local knowledge and building community buy‐in to restoration and management plans. We demonstrate a values‐based framework based on Multi‐Criteria Decision Analysis (MCDA) to develop a management plan for the Lake Wānaka catchment, making use of the fact that Aotearoa/New Zealand mandates action plans to consider community values. The MCDA‐framework successfully wove together cultural, ecological, and socio‐economic values. Clearly translating values into objectives and structuring them hierarchically allowed the identification of current system deficits and management scenarios to address them. Combining the estimated effects of potential actions with the process participants’ subjective preferences for high‐level objectives led to a clear prioritisation of management scenarios. The elicited preferences highlighted the community's collective perspective on the relative importance of local objectives, which is an optimal basis upon which to agree on a management plan. We recommend values‐based approaches such as MCDA as a way forward for inclusive freshwater co‐management not only in Aotearoa/New Zealand, but elsewhere as well. Glossary of Māori Terms: Aotearoa: the Māori name for New Zealand; Hui: a meeting; Iwi: the largest tribal unit in Māoridom; Kaitiakitanga: guardianship over the sky, sea, and land; Kākahi: large freshwater mussel species including Echyridella menziezii ; Kōaro: an endemic New Zealand fish species ( Galaxias brevipinnis ); kokopu: a group of endemic New Zealand fish species in the family Galaxiidae ; mahinga kai: resources that are customarily used/harvested; mātauranga Māori: Māori knowledge; Mauri: life force or vital essence inherent in all living things; Nohoaka: seasonal occupation site; Pā: a settlement/village; Pākehā: a non‐Māori New Zealander; Raupō: wetland plant (bullrush; Typha orientalis ); Rūnaka: small or local tribal unit; te ao Māori: the Māori world view acknowledging the interconnectedness and interrelationship of all living and non‐living things; te mana o te wai: a Māori concept that refers to the fundamental importance of water and recognises that protecting the health of freshwater protects the health and well‐being of the wider environment, including people; tuna: freshwater eels indigenous to New Zealand ( Anguilla dieffenbachii and Anguilla australis ); important mahinga kai species; waka: canoe

Nutrient export and population density relationships in a stream‐lake basin from the Patagonian Andean Region - Alejandro Sosnovsky; Mailén Elizabeth Lallement; Magalí Rechencq; María Valeria Fernández; Eduardo Enrique Zattara; Claudia Silvina Feijoó (New Zealand Journal of Marine and Freshwater Research, 2023)
Eutrophication is a key human‐induced stressor in streams and often a consequence of intensified land use. We characterised how population density influences dissolved nutrients and its ratio in Patagonian Andean streams during the baseflow hydrological period. Research was conducted at stream Gutiérrez drainage basin (41°09′36.18″S 71°24′37.19″W) located in Nahuel Huapi National Park, Argentina. A fraction of this basin corresponds to the city of San Carlos de Bariloche, where households use on‐site wastewater treatment systems (OWTS) not connected to the city's main sewer system. Our results reflect a positive relationship between population density and export of nitrate–nitrogen and soluble reactive phosphorus. Nitrates leaching from OWTS into groundwater were incorporated into the stream ecosystem, but phosphorus seemed to be retained by the soils. The increase in N:P ratio along with population density suggests the presence of additional N sources beyond OWTS. Our results are relevant in N‐limited ecosystems such as those from the Northwest‐Patagonian region. As a consequence, these aquatic systems are liable to eutrophication by increased demographic pressure. Thus, it would be necessary to consider and evaluate the use of alternative OWTS, with higher denitrification capacity, to reduce release of nitrates into groundwater.

Comparison of GPS‐derived ocean tide loading displacements with models in New Zealand - Zhongguan Liu; Linguo Yuan; Kunyan Han; Zhongshan Jiang; Changfu Chen (New Zealand Journal of Marine and Freshwater Research, 2023)
We investigate the tidal displacement signals of two principle semidiurnal () and diurnal () tidal constituents in New Zealand. We calculate the predicted loading displacements using the latest ocean tide models and Earth models. The results show that, for the constituent, the tide models FES2014b and TPXO9‐Atlas have subtle differences, and the vector differences between the Earth models shows that the regularity of the influence of the Earth model is weak. The vector difference of constituent have significant spatial coherence (about 0.2 mm). The residuals of constituent in the up component subtract about 0.2 mm across the entire areas after considering the anelastic dispersion. We find that the clear regional‐scale spatial coherence of the residuals exists in both constituents in all models even if spatial water density and compressibility have been considered. However, the spatial coherence of residuals disappears when the network‐mean value removed, and the reduction of RMS for constituent is close to the theoretical error of body tide (about 0.5 mm). We also find that for the different ocean tide models, part of the differences in residuals between the observations and predictions would be attributed to the choice of geocentric reference frame.

Protecting the small: preliminary investigation of bryozoan community change in New Zealand's oldest marine reserve - Hannah L. Mello; Dennis P. Gordon; John S. Ryland; Abigail M. Smith (New Zealand Journal of Marine and Freshwater Research, 2023)
Cape Rodney–Ōkakari Point Marine Reserve (North Island, New Zealand/ Te Ika‐a‐Māui, Aotearoa), is New Zealand's oldest marine reserve and includes one of the most visited beaches in the country. The reserve's effect on both target species and biogenic habitats is well‐documented. It is less well‐known, however, how protection affects other taxa. Here, we present two surveys, made nearly 50 years apart, of encrusting, intertidal bryozoans from Echinoderm Reef, quantify their relative abundance and species richness, and discuss possible reasons for the changes between 1971 and 2019. Prior to protection, encrusting bryozoans were common under boulders on Echinoderm Reef, a rocky intertidal mudstone terrace within the reserve. Since the reserve designation, however, there has been a decline in both abundance and species richness within this intertidal bryozoan community. Inconsistent sampling of the reserve's bryozoans makes it difficult to correlate changes in the bryozoan community with changes in the reserve's biotic and abiotic characteristics. Despite monitoring shortcomings, there is still value in the ad hoc biological surveys that have been performed, as they provide a snapshot of what communities were like at the time of collection. In the future, however, more research is needed to understand change within this bryozoan community.

Sexual reproduction of seagrass Zostera muelleri in Aotearoa New Zealand: are we missing a restoration opportunity? - Iñigo Zabarte‐Maeztu; Fleur E. Matheson; Merilyn Manley‐Harris; Ian Hawes (New Zealand Journal of Marine and Freshwater Research, 2023)
Seagrass Zostera muelleri has been reported to reproduce mainly asexually in New Zealand. However, a recent study in Tauranga Harbour suggested that flowering might occur more often than previously thought. Here we provide evidence of intertidal seagrass flowering events in six New Zealand estuaries in which it has not before been documented. Further research on seagrass sexual reproduction is desirable as we hypothesise that either flowering events have formerly been missed due to the cryptic nature of the flowers, or that sexual reproduction is emerging as a response to increasing pressures on seagrass ecosystems. In addition, with evidence of seagrass decline occurring globally, and likely also in New Zealand, we recommend collection of seagrass seeds to preserve genetic variability and to attempt restoration efforts through assisted sexual reproduction techniques that have not yet been used in New Zealand.

Marine aquaculture: A developing domain needing thorough planning, management and novel technological supports - Yuan Luo; Fang Qiao; Mei‐Ling Zhang; Zhen‐Yu Du (Reviews in Aquaculture, 2023)

A systematic review of fish adulteration and contamination in Bangladesh: A way forward to food safety - Md. Akhtaruzzaman Khan; Md. Emran Hossain; Md. Sayemul Islam; Mohammad Saidur Rahman; Pratheesh Omana Sudhakaran; Madan Mohan Dey (Reviews in Aquaculture, 2023)
For decades, the world has been plagued by widespread food adulteration, and Bangladesh is no exception. Dishonest business people and fish farmers unlawfully utilize various preservatives to avoid rotting and extend the shelf life of fish. Although previous research has examined the level of formalin use in fish bodies, no studies focusing on all aspects of fish adulteration and contamination in Bangladesh have been carried out. In this context, the aim of this review is to explore the extent and magnitude of illegal fish adulteration and contamination in Bangladesh. Among the 37 reviewed studies, 11 of them highlighted formalin adulteration in fish samples and fish feed. The extent of formalin use varied between local and imported fish, and between large and small fish. Imported and large fish were substantially more formalin‐contaminated. Several investigations have discovered that antibiotic levels in farm water and fish feed exceed the permitted level. Farmers have used growth promoters incautiously. This study also identifies that certain metal substances, such as chromium, lead, arsenic, cadmium, iron, mercury and cobalt, have been frequently found in fish bodies and feed samples. Furthermore, a distinct type of fish adulteration caused by aromatic compounds has emerged recently. The findings and their ramifications are extremely concerning for human lives. However, since each study employed a different testing kit, the results were quite distinct. Thus, the adoption of a precise and sensitive kit is strongly recommended. The government should make it a top priority to solve the problem of fish adulteration by implementing appropriate food safety laws and policies.

Inorganic nanoparticles for use in aquaculture - Seerengaraj Vijayaram; Konstantina Tsigkou; Antonio Zuorro; Yun‐Zhang Sun; Holy Rabetafika; Hary Razafindralambo (Reviews in Aquaculture, 2023)
Nanotechnology is a rising technology dealing with nanoparticle‐based (1–100 nm) organic and inorganic materials. Such technology has a vital role in various industrial sectors, including pharmaceuticals, nuclear energy, fuel and energy, electronics, and bioengineering, while having potential applications to human, animal, plant, and environmental health. Even though nanomaterial applications can cover multi‐areas of biological and natural fields, limited information are available in the aquaculture sector. Nowadays, the aquaculture sector is the most imperative field to meet animal protein requirements for human nutrition, and aquaculture disease outbreaks as well as the aquatic environment pollutants are significant hindrances in producing healthy aquatic products. The current review aims to enlighten the direction of nanotechnology in the aquaculture industry while providing more specific information about inorganic forms of nanoparticles used to develop several types of applications such as antimicrobial, antibiofilm and photocatalytic agents, as well as aquatic animal nutrition in the domain of aquaculture. A large number of inorganic nanoparticles and their use as animal feed and for water treatment are extensively described. Their potential risks in aquaculture are also presented and discussed. The aquaculture nanotechnology applications are expected to contribute to fish health improvement, harmful microbes control, and aquatic products nano‐delivery in the forthcoming years.

Cover Image - Jianbo Yuan; Yang Yu; Xiaojun Zhang; Shihao Li; Jianhai Xiang; Fuhua Li (Reviews in Aquaculture, 2023)
The cover image is based on the Review Article Recent advances in crustacean genomics and their potential application in aquaculture by Jianbo Yuan et al., https://doi.org/10.1111/raq.12791 . image

A strategic review and research roadmap for offshore seaweed aquaculture—A case study from southern Australia - Wouter Visch; Cayne Layton; Catriona L. Hurd; Catriona Macleod; Jeffrey T. Wright (Reviews in Aquaculture, 2023)
Global seaweed aquaculture production has more than tripled since 2002 and is dominated by Asian countries with farming operations that typically occur in relatively wave‐protected, nearshore areas. To meet future demand, production must move to “non‐traditional” regions and into less contested waters offshore. However, the technological complexities and uncertainties in the performance of seaweed cultivated in high‐energy offshore environments are substantial and must be overcome. Here, we identify knowledge gaps and suggest a research roadmap to inform the advancement of a commercial offshore seaweed aquaculture industry using southern Australian species as case studies: (1) Durvillaea spp. (order Fucales); (2) four kelps (order Laminariales); and (3) the rhodophyte Asparagopsis . These groups lie along a spectrum of commercial viability and readiness for offshore aquaculture, and key knowledge gaps are cultivation technology and the suitability to offshore conditions. Cultivation of Durvillaea is restricted by a low level of biological and technical understanding, but there is high market potential and readiness. For laminarian kelps, commercial production in nearshore conditions is already occurring elsewhere, which make them the most likely candidate for offshore cultivation in the medium term. Asparagopsis is least suited to offshore conditions, with substantial gaps in general cultivation knowledge, and its cultivation is likely to be restricted to land‐based systems or relatively sheltered nearshore waters. The knowledge gaps identified here will inform research and development programs to advance offshore seaweed aquaculture in southern Australia and globally.

Portuguese‐Brazilian abstracts (Reviews in Aquaculture, 2023)

Tilapia lake virus disease: Vaccine strategies to control the threat to tilapia aquaculture - Sreeja Lakshmi; David Smith; Ha Thanh Dong; Kim D. Thompson; Preetham Elumalai (Reviews in Aquaculture, 2023)
Since the first report of a novel disease caused by tilapia lake virus (TiLV) in 2014, the disease (TiLVD) has gained considerable attention as one of the most devastating viral diseases in tilapia aquaculture globally. The virus is both highly virulent and transmissible and has been detected in many countries worldwide. It poses a severe threat to the global tilapia aquaculture industry, food security and many people's livelihoods in low and middle‐income countries. The absence of effective treatment strategies and inadequate biosecurity measures means the virus's rapid spread is likely to continue. Vaccination has proven to be an effective approach to preventing and controlling disease in finfish aquaculture. The vaccine's efficacy and the delivery system's suitability are essential for evoking an appropriate immune response against the pathogen. The purpose of this review is to provide an overview of the strategies being used to develop vaccines for TiLVD. Nanovaccines, which offer a new approach to prevent TiLVD in farmed tilapia, are also discussed.

Arabic Abstracts (Reviews in Aquaculture, 2023)

Autophagy regulation of virus infection in aquatic animals - Chen Li; Yunli Zhang; Xianliang Zhao; Li Li; Xianghui Kong (Reviews in Aquaculture, 2023)
Autophagy is a conserved intracellular degradation process that is required to maintain host homeostasis and cope with invading pathogens. Over the past few decades, studies on mammals have greatly increased our understanding of the relationship between autophagy and virus infection. Autophagy may convey the invader to lysosomes to degrade or activate the host immune response against virus replication. However, many viruses have developed some strategies that evade the degradative nature of autophagy or hijack this pathway for their gain. It follows that autophagy during viral infection is a double‐edged sword. In contrast to mammals, the review on autophagy modulated by the aquatic animal virus is limited. Here, after a brief description of the main information about autophagy, we highlight current progress on the interplays between autophagy and virus infection in aquatic animals, including the phenomenon of autophagy upon virus infection, the effect of modulating autophagy on virus replication, and the crosstalk between autophagy and immune response during virus infection. This review will help us better understand the pathogenic mechanism of aquatic animal viruses and develop proper antiviral countermeasures aimed at modulating autophagy.

Physiological function of vitamin D 3 in fish - Ke Cheng; Yanqing Huang; Chunfang Wang; Wajeeha Ali; Niel A. Karrow (Reviews in Aquaculture, 2023)
Vitamin D (VD) is a steroid hormone, of which vitamin D 3 (VD 3 ) is the main form in fish. Fish obtain VD 3 majorly from diets, and VD 3 has been widely used in aquatic feed as feed additive. As one of the essential nutrients, VD 3 plays an indispensable role in the growth and health of fish. Due to the particularity of the fish living environment, the metabolic and physiological functions of VD 3 in fish have some differences from those of mammals. This paper reviews the metabolic process of VD 3 in fish, the main metabolites and vitamin D receptors, compares the differences in VD 3 metabolism between fish and mammals, summarises the recommended dietary requirements for VD 3 in several fish species, generalises the role of VD 3 in fish growth performance, bone development, lipid metabolism, immune regulation, antioxidant and other potential physiological functions, as well as its synergistic effects with other nutrients. Future perspectives of VD 3 application in aquaculture are proposed. Understanding the metabolic process and physiological function of VD 3 is of great significance for extending VD 3 application in the aquatic feed industry.

Disease prevention and mitigation in US finfish aquaculture: A review of current approaches and new strategies - Alex Wright; Xunde Li; Xiang Yang; Esteban Soto; Jackson Gross (Reviews in Aquaculture, 2023)
In the United States, the aquaculture industry has not seen the same levels of growth in production as other countries—made evident by the $17 billion seafood trade deficit estimated in 2020. Nevertheless, aquaculture remains an important industry fully capable of supplementing the domestic seafood supply and reducing the US seafood trade deficit. Infectious diseases is one of several factors that threatens the capability and sustainability of the aquaculture industry, highlighting the importance of effective control strategies for these pathogens. Antimicrobial products are often used to control and eliminate undesirable microbes in effort to prevent or mitigate the impacts of infectious diseases. Some pathogens are capable of adapting to and resisting the antimicrobial effects, escalating the challenges associated with disease management in aquaculture. Antimicrobial resistance (AMR) is now recognised by numerous national and international agencies as a top global health concern and is problematic for US aquaculture. Currently, disease prevention and mitigation strategies utilised by US finfish aquaculture can be broken down into three levels; comprehensive protocols (biosecurity, disease response), good husbandry strategies (stress management, proper diet, optimal environment) and effective antimicrobial products (biocides, therapeutics). This review will discuss how each level contributes differently to the overall protection of fish from pathogens. In the era of AMR, this review will also highlight current and emerging alternative strategies that do not rely on traditional antimicrobial products (e.g., vaccines, dietary supplements, novel antimicrobial, stock selection) for disease prevention and mitigation.

A global review of protected species interactions with marine aquaculture - Gretchen E. Bath; Carol A. Price; Kenneth L. Riley; James A. Morris (Reviews in Aquaculture, 2023)
As marine aquaculture expands around the world, there is increased concern for impacts to protected species. Documented cases of marine mammal, sea turtle, seabird, and shark interactions with aquaculture installations do exist but are challenging to find. This extensive review summarises the state of knowledge of protected species interactions with marine fish and shellfish aquaculture installations. Although seaweed aquaculture was beyond the scope of this review, some of the findings for shellfish and finfish aquaculture may be relevant. The potential impacts of farms including habitat exclusion, entanglement, entrapment, collisions, and behavioural modifications are the primary risks posed to protected species by marine aquaculture facilities and operations. In addition, indirect effects from habitat impacts of farm operations may be of concern in some areas as well as the cumulative impacts of multiple small or large farms in the same general vicinity. Decades of farm innovations and best management practices have been driven by industry, natural resource managers, conservation organisations, and international conservation agreements. This review is useful for informing industry planning and permitting to develop aquaculture in the open ocean. This work will help advance the science of conservation by synthesising the state of knowledge and provide managers and industry with more insight to protect the most vulnerable species.

Role of microbial phytases in improving fish health - Priya; Ishita Virmani; Pragya; Ravi Kumar Goswami; Bijender Singh; Jai Gopal Sharma; Bhoopander Giri (Reviews in Aquaculture, 2023)
Fishmeal is the most preferred protein source in aquafeed industry due to its balanced amino acid and fatty acid profile, but its limited global supply and high price value, necessitates researchers to focus on sustainable alternative sources of protein and plant‐based feed, to meet the growing demand of fish feed. Phytate is a reservoir of phosphorus present in the plants; however, its chelating ability makes it anti‐nutritional. Phytate forms complexes with minerals, proteins, lipids and carbohydrates, confining their accessibility in fish feeds, hence, additional dietary nutrients are required in the fish feed to overcome nutritional deficiencies. The elimination of phytate‐phosphorus through animal faeces and its pass on to aquatic bodies leads to enrichment of nutrients, eutrophication and algal blooms. Microbial phytase segregates phosphorus, minerals, proteins and lower inositol phosphates from phytate. The supplementation of fish feed with microbial phytase enhances the digestibility of minerals, due to which less nutrients are excreted in the faeces; therefore, minimizing pollution in water bodies. Monogastric and agastric animals inherently exhibit the deficiency of phytase; hence, supplementation of dietary material with phytase has been an emerging choice to make dietary nutrients available for fish. Moreover, microbial phytases have a broad pH range and are thermostable, which makes them an excellent choice for commercial fish feed production. Additionally, microbial phytase improves fish growth as these enzymes enhance nutrients bioavailability and their digestion. This review article presents the application of microbial phytases as a feed additive, and their role in enhancing fish growth.

High above the mountains, far across the sea—Aquaculture is helping to eradicate poverty in one of the world's most remote areas - Houguo Xu; Changlin Liu; Baoliang Liu; Jie Li (Reviews in Aquaculture, 2023)

Spanish abstracts (Reviews in Aquaculture, 2023)

Women engagement, psychological traits, and gender gaps in the small‐scale seaweed aquaculture in Chile - César Salazar; Marcela Jaime; Roberto Cárdenas Retamal; Marjorie Baquedano (Reviews in Aquaculture, 2023)
Women's participation in small‐scale aquaculture is growing, but women producers remain in a disadvantaged position compared to men. Reducing gender gaps is at the core of many development programs, but little is known regarding the source of these differences. This paper investigates the main drivers of gender gaps in seaweed small‐scale aquaculture by focusing on the analysis of differences between male and women, and across a series of psychological traits. We use data from a sample of 152 seaweed producers from central‐southern Chile and perform a matching procedure to generate a balanced sample of male and female producers in the dimensions determining their performance in the sector. Our results show that female producers may exhibit more positive psychological traits such as patience and interpersonal trust. However, women's choices in seaweed farming may be incongruent with these characteristics, as expecting more immediate returns than males, and may not be able to exploit the advantages of collaboration in selling in the sector. This supports the notion that opportunity costs (e.g., other activities in the marine area) and outside options (e.g., fishing versus trade) may be one of the major drivers of gender gaps and suggests that there are barriers keeping women from exploiting their potentially advantageous individual characteristics. Results provide important insights for the design of support instruments aimed at reducing these barriers faced by women in the sector.

Bioeconomic modelling in tilapia aquaculture: A review - Juan Carlos R. Dorantes‐de‐la‐O; Alfonso N. Maeda‐Martínez; Luis D. Espinosa‐Chaurand; Rodolfo Garza‐Torres (Reviews in Aquaculture, 2023)
The global production of aquatic resources is increasing at the rate of 3.3 million tons per year, main thanks to aquaculture. However, this industry is considered by financial institutions as high risk due to failures caused by epizootics, natural disasters and poor planning and monitoring. Bioeconomic modelling is a progressive branch of social science that seeks to integrate the disciplines of economics and biology to create theories that better explain economic events using a biological basis and vice versa. This should be used in aquaculture to plan, monitor, and determine cost‐effectiveness and risk, to reduce uncertainty and increase profits of ongoing or new projects. A meta‐analysis of the literature on bioeconomic modelling in aquaculture during 26 years (1994─2020) was performed, using four search engines. Sixty‐eight articles were published in 23 journals, on 25 groups of species or species. The most studied were shrimp, tilapia, seabream, salmon and carp. From these, 12 articles dealt with tilapia models that shared similar biological, management and economic sub‐models. In the 26‐year analysis, the global scientific productivity in this field is low (2.6 articles/year) in relation to the growth of world aquaculture. Bioeconomic modelling peaked during the decade from 2004 to 2014 with 5.6 papers/year, but then declined to only 0.83 articles/year from 2015 to 2020. This is possibly due to the low diffusion among producers, planners and financial institutions of the advantages of the models and the difficulty to use them if friendly and readily available software is lacking.

Planning and licensing for marine aquaculture - Lynne Falconer; Karl Cutajar; Amalia Krupandan; Elisa Capuzzo; Richard A. Corner; Tim Ellis; Keith Jeffery; Eirik Mikkelsen; Heather Moore; Francis X. O'Beirn; Pauline O'Donohoe; Neil M. Ruane; et al. (Reviews in Aquaculture, 2023)
Marine aquaculture has the potential to increase its contribution to the global food system and provide valuable ecosystem services, but appropriate planning, licensing and regulation systems must be in place to enable sustainable development. At present, approaches vary considerably throughout the world, and several national and regional investigations have highlighted the need for reforms if marine aquaculture is to fulfil its potential. This article aims to map and evaluate the challenges of planning and licensing for growth of sustainable marine aquaculture. Despite the range of species, production systems and circumstances, this study found a number of common themes in the literature; complicated and fragmented approaches to planning and licensing, property rights and the licence to operate, competition for space and marine spatial planning, emerging species and diversifying marine aquaculture production (seaweed production, Integrated Multi‐Trophic Aquaculture [IMTA], nutrient and carbon offsetting with aquaculture, offshore aquaculture and co‐location and multiuse platforms), and the need to address knowledge gaps and use of decision‐support tools. Planning and licensing can be highly complicated, so the UK is used as a case study to show more detailed examples that highlight the range of challenges and uncertainty that industry, regulators and policymakers face across interacting jurisdictions. There are many complexities, but this study shows that many countries have undergone, or are undergoing, similar challenges, suggesting that lessons can be learned by sharing knowledge and experiences, even across different species and production systems, rather than having a more insular focus.

The management of the sea lice in Chile: A review - Sandra Bravo; James Treasurer (Reviews in Aquaculture, 2023)
Sea lice infestations have the largest economic and biological impact on salmon farming in Chile, similar to that seen in salmon‐producing countries in the northern hemisphere. Caligus teres infesting coho salmon ( Oncorhynchus kisutch ) was first recorded in 1981, but Caligus rogercresseyi has been the predominant species infesting Atlantic salmon ( Salmo salar ) and rainbow trout ( Oncorhynchus mykiss ) from 1997. In contrast, coho salmon has been shown to be resistant to this sea louse species. Regulations to establish integrated pest management of sea lice were implemented by the Chilean authority in 2007. However, to date, pharmacological medicines have been the main tool used by the salmon farming industry in Chile to manage sea lice, although non‐pharmacological treatments have been available since 2016. Production of farmed salmon reached 978.274 tons in 2021 and 7.72 g of medicines was prescribed per ton of harvested salmon. The highest volumes used in that year were Azamethiphos (47%) and hexaflumuron (45.5%), in addition to 5532 tons of hydrogen peroxide. This review updates the current management of sea lice in Chile and also summarizes the biological knowledge of this important parasite.

Recent advances in crustacean genomics and their potential application in aquaculture - Jianbo Yuan; Yang Yu; Xiaojun Zhang; Shihao Li; Jianhai Xiang; Fuhua Li (Reviews in Aquaculture, 2023)
Genomic resources are increasingly being used to improve the production efficiency and profitability of aquaculture. Crustaceans are a large group of invertebrates that encompasses some of the most important farmed species in the aquaculture industry. However, very few crustacean genomes have been published although an aquaculture genome project was proposed as early as 1997. Breakthroughs in next‐generation and third‐generation sequencing technologies and the development of high‐complexity sequence assembly strategies have promoted the publication of an increasing number of crustacean genomes, thus paving a broad way for biological and genetic studies and applications in aquaculture. In this review, we summarize recent advances in crustacean genomic research as of June 2022, including genome sequencing and assembly, genomic characteristics, and the genetic mechanisms underlying various biological phenotypes, such as environmental adaptation, lifestyle, development, and sex determination. This review also discusses the application of crustacean genomes in aquaculture, including genetic dissection of economic traits and genome‐based selective breeding via genome‐wide association studies and genomic selection. High‐quality genomes are important not only for understanding the genetic basis of biologically and economically important traits but also for the genetic improvement of aquaculture species. However, the utilization of crustacean genomics still lags far behind those in other animals. Therefore, additional multi‐omics studies and technological development are needed to accelerate the application of genomics in aquaculture.

Microalgae with immunomodulatory effects on fish - Abir Bahi; Abel Ramos‐Vega; Carlos Angulo; Elizabeth Monreal‐Escalante; Francisco A. Guardiola (Reviews in Aquaculture, 2023)
In recent decades, microalgal biotechnology has become one of the most valuable sources of functional feed additives. Many microalgae, such as Chlorella sp., Tetraselmis sp., Navicula sp . , Phaeodactylum tricornutum , Porphyridium cruentum , Nannochloropsis gaditana , Dunaliella salina , Lobosphaera sp. and Schizochytrium sp., have been considered valuable in fish species as they enhance immunostimulant abilities, resistance against infectious diseases and tolerance to environmental stress. For instance, immunological parameters (i.e., respiratory burst activity, phagocytic capacity and IgM production) and immune‐related gene expression (i.e., proinflammatory cytokines) in fish have been manly analysed, demonstrating modulation upon microalgal administration. Moreover, disease resistance to microbial pathogen challenges has also been evidenced in several studies. In this context, the present literature review aims to assemble and reveal published research about the immunostimulant properties of some microalgae and their compounds in the immune systems of farmed fish species, whether model or new, with a high potential for aquaculture. Overall, it remains unclear how microalgae or their bioactive compounds may induce or modulate signals in the immune systems of fish species; however, the inclusion of different microalgal species in fish feed has improved the immune response and increased survival to stress conditions and infectious challenges.

Reassortant viruses threatening fish aquaculture - Yulema Valero; Alberto Cuesta (Reviews in Aquaculture, 2023)
Aquaculture provides more than half of fish destined for human consumption worldwide. In aquaculture, infectious diseases triggered by viruses are amongst the major cause of mortality of farmed fish. The cohabitation of different virus strains in the same geographical area opens the possibility to natural reassortment. Virus reassortment is a characteristic recombination process of segmented viruses in which different viruses merge their genome by the shuffling of complete segments. This is possible when two or more viral strains are cohabitating into a single host, boosting their probability to concatenate their viral cycles, getting to pack segments from distinct parental strains. Cohabitation of different viruses in a geographical area, and therefore the possibility of natural reassortment, has been aided by the increment in the transport of eggs and larvae between facilities around the world. Reassortant viruses have been described to show special tropisms for fish species opposed from those affected by parental virus strains, entailing an emerging threat for aquaculture but also for wild populations. To date, outbreaks of reassortant strains of infectious pancreatic necrosis virus, nodavirus (NNV), infectious salmon anaemia virus and tilapia lake virus have been described. Unfortunately, only the characterization of reassortant NNV has been explored. The aim of this review is compiling the information available concerning reassortant viruses affecting fish species of relevance for aquaculture highlighting their potential impact for the sector. Additionally, recent research advances in host‐NNV interaction are also included.

Insect lipid in fish nutrition: Recent knowledge and future application in aquaculture - Md. Sakhawat Hossain; Brian C. Small; Ronald Hardy (Reviews in Aquaculture, 2023)
Insect lipid/oil is a by‐product of insect meal production. The quantity and nutritional quality of insect lipid varies with species, life stages, the kind of substrate used to raise the insects, as well as the extraction process. Insect lipid products have been successfully used in animal feeds as source of nutrients, notably energy and indispensable fatty acids. Further some insect lipid products are potential functional ingredients in feed formulations because of the existence of some functional compounds, for example, lauric acid and monolaurin in black solder fly larvae oil (BSFLO). To date, research on the effects of insect product inclusion in aquafeed mainly focused on insect meal as protein source rather than insect oil/lipid as a lipid source. Research to date indicates that insect lipids can replace traditional energy sources in fish nutrition without negatively affecting fish growth and feed utilization performance. By raising the amount of long‐chain polyunsaturated fatty acids in fish fillets, insect lipids can improve fillet quality. Insect lipids may also positively influence general health of fish by stimulating the immune system and manipulating the gut microbiota. As there is a crucial need for searching alternate lipid sources in aquafeed to extend limited global supplies of fish oil and due to the insect lipids content and its fatty acid quality, there is a pressing need to expand experimentation concerning their application in aquafeed to support sustainable growth of the aquaculture industry.

Review of alternatives to antibiotic use in aquaculture - Melba G. Bondad‐Reantaso; Brett MacKinnon; Iddya Karunasagar; Sophie Fridman; Victoria Alday‐Sanz; Edgar Brun; Marc Le Groumellec; Aihua Li; Win Surachetpong; Indrani Karunasagar; Bin Hao; Andrea Dall'Occo; et al. (Reviews in Aquaculture, 2023)
With the rapid growth of the aquaculture production since the 1980s, there has been a concomitant increase in disease outbreaks. The injudicious and/or incorrect use of antimicrobial agents against diseases of farmed aquatic species poses a considerable threat to the development and growth of a successful and sustainable aquaculture industry. An increase in antimicrobial resistance (AMR) is an important consequence, resulting to the difficulty in treating common bacterial diseases in populations of aquatic organisms, combined with the presence of antibiotic residues in food fish and their products, leading to import refusals and negative impacts on international trade. To reduce the frequency of AMR, good aquaculture and effective biosecurity practices should include the prudent and responsible use of antibiotics and also consider the use of alternatives to antibiotics, in addition to disease prevention management. This article reviews the literature discussing the scope of the problem pertaining to antibiotic use, the emergence of AMR in aquaculture and to consider and discuss viable alternatives (e.g., vaccination, bacteriophages, quorum quenching, probiotics and prebiotics, chicken egg yolk antibody and medicinal plant derivative). We also discuss lessons learnt, from specific case studies such as the vaccination of farmed salmon in Norway and the use of ‘specific pathogen‐free’ seed—as primary and essential part of a biosecurity strategy.

Single cell genomics as a transformative approach for aquaculture research and innovation - Rose Ruiz Daniels; Richard S. Taylor; Diego Robledo; Daniel J. Macqueen (Reviews in Aquaculture, 2023)
Single cell genomics encompasses a suite of rapidly maturing technologies that measure the molecular profiles of individual cells within target samples. These approaches provide a large up‐step in biological information compared to long‐established ‘bulk’ methods that profile the average molecular profiles of all cells in a sample, and have led to transformative advances in understanding of cellular biology, particularly in humans and model organisms. The application of single cell genomics is fast expanding to non‐model taxa, including aquaculture species, where numerous research applications are underway with many more envisaged. In this review, we highlight the potential transformative applications of single cell genomics in aquaculture research, considering barriers and potential solutions to the broad uptake of these technologies. Focusing on single cell transcriptomics, we outline considerations for experimental design, including the essential requirement to obtain high quality cells/nuclei for sequencing in ectothermic aquatic species. We further outline data analysis and bioinformatics considerations, tailored to studies with the under‐characterized genomes of aquaculture species, where our knowledge of cellular heterogeneity and cell marker genes is immature. Overall, this review offers a useful source of knowledge for researchers aiming to apply single cell genomics to address biological challenges faced by the global aquaculture sector though an improved understanding of cell biology.

Toxicity assessment and anti‐ Vibrio activity of essential oils: Potential for application in shrimp aquaculture - Xiaoting Zheng; Peter Bossier (Reviews in Aquaculture, 2023)
This present paper aimed to review the past 4 years (2019–2022), the inhibition of Vibrio spp. (including Vibrio 's causing AHPND) by EOs, as well as the potential toxicity of the EOs towards crustaceans, with an emphasis on Artemia spp. In the present review, 27 EOs from terrestrial plants are reported regarding their anti‐ Vibrio activity. Among these 27 studies, Salvia officinalis and Thymus vulgaris (Lamiaceae family) were found to be the most numerous. Among the Vibrio spp., V. parahaemolyticus (non‐AHPND strain) was mostly researched. There are in total 68 publications about the toxicity of EOs in Artemia spp . Based on the four categories of toxicity towards Artemia (strongly toxic: LC 50 50 :100–500 μg/ml, weakly toxic: LC 50 : 500–1000 μg/ml, and non‐toxic: LC 50 > 1000 μg/ml), strong toxicity activity was found in 37 EOs, moderate toxicity in 15 EOs, weak activity for three EO plants and 13 non‐toxic extracts. In fact, LC 50 values as low as 10.25 and 11.48 μg/ml were described in Artemisia vulgaris and Euryale ferox , respectively, showing these two plant EOs are strongly toxic to Artemia . Overall, and despite being generally considered “eco‐friendly and natural” products and safer than antibiotics, some of the EOs are toxic to target organisms. Thus, to establish an ecologically safe application of EOs in shrimp aquaculture, the correct use of these plant EOs (in terms of concentrations and duration) in aquaculture should be considered.

Quorum‐sensing interference in vibrios - Shanshan Zhang; Qian Yang; Mieke Eggermont; Tom Defoirdt (Reviews in Aquaculture, 2023)
Vibrios belonging to the Harveyi clade and the Splendidus clade are important pathogens that cause high economic losses in aquaculture. To control bacterial diseases, antibiotics have been widely applied in aquaculture worldwide for many years, contributing to the development and spread of antibiotic resistance. To further limit the use of antibiotics without affecting the envisaged sustainable growth of the sector, novel therapies to control diseases are urgently needed. As the virulence of many bacterial pathogens is controlled by quorum sensing, quorum‐sensing interference has been the most intensively studied antivirulence therapy. It aims to disarm rather than kill the pathogens to prevent them from attacking their host. This strategy is believed to impose less selective pressure upon pathogens for resistance development when compared to antibiotics. In this review, we provide an overview of quorum‐sensing systems in vibrios belonging to the Harveyi clade and the Splendidus clade, as well as the virulence‐related phenotypes controlled by these systems. The major quorum‐sensing systems in these bacteria include three‐channel quorum‐sensing systems and indole signalling. Furthermore, we discuss different agents that interfere with quorum‐sensing systems and that protect aquatic animals from disease caused by Harveyi clade and Splendidus clade vibrios. These agents include small molecules (both natural and synthetic) that interfere with three‐channel quorum‐sensing systems or with indole signalling and signal molecule‐degrading bacteria. Finally, we identify knowledge gaps and propose some frontiers for further research in order to move this promising field forward.

A refined roadmap to decapod sexual manipulation - Ai Hang Tran Nguyen; Susan Glendinning; Tomer Ventura (Reviews in Aquaculture, 2023)
Many decapod crustaceans with sexual dimorphism in body size are economically significant species for fisheries and aquaculture, making monosex culture a desirable practice to increase farmers' yield and profits. It is well established that the male‐specific androgenic gland (AG) mediates masculinization in decapods by producing and secreting the insulin‐like AG hormone (IAG). However, IAG is not a sex‐determining factor; hence, iag silencing in decapods does not always lead to successful sex change. Since the establishment of monosex populations in the giant freshwater prawn Macrobrachium rosenbergii , the same AG/ iag manipulation approach has been attempted in economically significant penaeid shrimps, crabs, crayfish and spiny lobsters, to no avail. There are many factors at play with species‐specific intricacies which require close examination when addressing monosex production. This review provides a refined roadmap to successful sexual manipulation in decapod crustaceans, highlighting the key caveats to be considered and critical gaps in knowledge such as the timing of iag expression compared to the development of sexual characteristics, the relationship between iag and a master regulator, as well as silencing capacity. Lastly, this review examines what the future might hold for monosex aquaculture in decapods, taking into consideration novel technologies such as gene editing.

Issue Information (Reviews in Aquaculture, 2023)

Chinese abstracts (Reviews in Aquaculture, 2023)

Transitions, challenges and trends in China's abalone culture industry - Xiaolong Gao; Mo Zhang; Xuan Luo; Weiwei You; Caihuan Ke (Reviews in Aquaculture, 2023)
Abalone species are economically important shellfish in China's aquaculture industry. In 2020, China's abalone aquaculture production was 203,500 tonnes, accounting for nearly 90% of total global production. However, many problems have accompanied the rapid development of this industry, including a reduction in near‐shore space suitable for culture and the risk of exposure of farms to natural disasters such as typhoons and red tides. In addition, high temperatures and low oxygen levels resulting from global climate change are causing increased abalone mortality in summer. In this review, the culture patterns and characteristics used in different countries are compared with respect to larvae nurseries, intermediate juvenile culture and the grow‐out phase. Next, the transitions and challenges in China's abalone culture industry over the past 60 years are summarized. Finally, a coordinated land‐sea program for reducing solid waste emissions into the water and increasing carbon sinks is suggested based on the ‘Carbon Neutrality’ theory. Under the framework of the program, new facilities, technologies and models should be created to achieve increased mechanization and a greater understanding of the abalone aquaculture industry as soon as possible. This review provides references and data to support the scientific planning and mapping of China's abalone culture industry as well as the transition of China's perceived identity from a major fishery country to a strong fishery power with an awareness of environmental protection and resource use.

The feeding ecology of grass carp: A review - Lisen Li; George Balto; Xiaoyan Xu; Yubang Shen; Jiale Li (Reviews in Aquaculture, 2023)
As an economically important herbivorous fish, the range of grass carp ( Ctenopharyngodon idella ) has expanded in the world and its ecological influences have become more evident. Currently, we have embarked on assessing the effect of grass carp on aquatic organisms and water quality by integrating the outcomes from previous ecological studies. Bibliographical data integration shows that aquatic plant preference is likely to be related to the cellulose proportion, calcium, sucrose and citric acid of the aquatic plant. Moreover, pharyngeal teeth and multiple gene copies of taste receptors could help reveal the feeding mechanism of grass carp. The expansion of the number of sweet‐detecting T1R2 genes, and the functional potential of Umami taste receptor T1R3 by calcium‐regulation was speculated on the basis of previous experimental observations of grass carp, suggesting that aquatic plant consumption by this species is tightly associated with the taste receptors. Apart from the competition in living space between grass carp and other fish, the effects of consuming zooplankton and zoobenthos were summarized to reveal general passive feeding of grass carp, as well as the feeding choice in the absence of aquatic plants. Water quality data were gleaned to make comparative analyses between groups stocking with and without grass carp to uncover changes in water physicochemical parameters in short‐ (

Beneficial effects, challenges and opportunities of the filamentous fungus, Aspergillus niger with special reference to the shrimp feed industry—A review - Rajabdeen Jannathulla; Jagabattula Syama Dayal (Reviews in Aquaculture, 2023)
The shrimp industry, including its culture and feed sectors, exhibited steady growth over the years with a reduced cost–benefit ratio due to increasing production costs attributed mainly to enhanced feed costs. The unsustainable availability and rapid increase in fishmeal cost have forced the aquafeed sector to reduce dietary inclusion levels. The filamentous fungus, Aspergillus niger plays an important role in utilising plant protein sources for formulating cost‐effective shrimp feed. A . niger has been reported to produce numerous hydrolytic enzymes to degrade the limiting factors of plant proteins such as antinutrients and fibre fractions. This fungus enhanced not only the quantity but also the quality of proteins and amino acids, especially methionine and lysine. Likewise, it also increased the availability of soluble minerals, particularly phosphorous, by degrading the phytic‐phosphorus, thereby helping to replace dietary fishmeal up to 80% in penaeid shrimps. Consequently, this fungus could reduce feed formulation cost significantly. However, the mycotoxins produced by this fungus pose difficulties during large‐scale fermentation, and its implications on the workers and environment cast doubt about its efficacy and utility. However, recent developments indicate that A . niger could be an alternative choice in reducing the pressure on fishmeal demand by enhancing the nutrient utilization of plant‐based materials leading to the formulation of, cost‐effective feeds that can sustain shrimp culture and production in the future.

Quorum sensing signals: Aquaculture risk factor - P. Snega Priya; Seenivasan Boopathi; Raghul Murugan; B. Haridevamuthu; Aziz Arshad; Jesu Arockiaraj (Reviews in Aquaculture, 2023)
Bacteria produce several virulence factors and cause massive mortality in fish and crustaceans. Abundant quorum sensing (QS) signals and high cell density are essentially required for the production of such virulence factors. Although several strategies have been developed to control aquatic pathogens through antibiotics and QS inhibition, the impact of pre‐existing QS signals in the aquatic environment has been overlooked. QS signals cause detrimental effects on mammalian cells and induce cell death by interfering with multiple cellular pathways. Moreover, QS signals not only function as a messenger, but also annihilate the functions of the host immune system which implies that QS signals should be designated as a major virulence factor. Despite QS signals' role has been well documented in mammalian cells, their impact on aquatic organisms is still at the budding stage. However, many aquatic organisms produce enzymes that degrade and detoxify such QS signals. In addition, physical and chemical factors also determine the stability of the QS signals in the aqueous environment. The balance between QS signals and existing QS signals degrading factors essentially determines the disease progression in aquatic organisms. In this review, we highlight the impact of QS signals on aquatic organisms and further discussed potential alternative strategies to control disease progression.

Penaeus vannamei inland farming: Perspectives and opinions - Otávio Augusto Lacerda Ferreira Pimentel; Luke Aaron Roy; Elizabeth Pereira dos Santos; Valdemir Queiroz de Oliveira; Luis Otavio Brito (Reviews in Aquaculture, 2023)

Mineral nutrition in penaeid shrimp - Ha H. Truong; Barney M. Hines; Maurício G. Emerenciano; David Blyth; Sarah Berry; Tansyn H. Noble; Nicholas A. Bourne; Nicholas Wade; Artur N. Rombenso; Cedric J. Simon (Reviews in Aquaculture, 2023)
This review summarises the current knowledge of mineral nutrition for penaeid shrimp. It investigates how the aquatic environment and the lifecycle of shrimp affect requirements and the role that minerals play in shrimp health. Methods of supplying minerals via either water or to feed, and novel ways of supplementing minerals within feed, are discussed. The requirements for individual minerals are summarised with recommendations for minimum levels of dietary inclusion for semi‐intensive and intensive commercial shrimp culture presented where data permits. Estimates of dietary requirement remain broad for most minerals for the main shrimp production species ( Penaeus vannamei , Penaeus monodon and Penaeus japonicus ), with some essential minerals remaining unstudied (Table 2 in Section 5.10). Mineral nutrition will become more important as intensification and diversification of production systems provide new challenges to shrimp aquaculture.

Root‐released organic compounds in aquaponics and their potential effects on system performance - Paula Senff; Björn Baßmann; Frederik Kaiser; Harvey Harbach; Christophe Robin; Pascal Fontaine (Reviews in Aquaculture, 2023)
Optimizing production in aquaponics requires in‐depth knowledge of the plant, fish and microbial compartments. This opinion paper is focused on root‐released organic compounds and their implication in aquaponics, an area that has received little to no direct research to date. Key scientific literature from two distinct fields of study—phytochemicals in aquaculture science and root exudates in plant science—reveals possible pathways and effects. Root exudates, passively or actively released by plants as a stress response, protection or signalling, have the potential to influence the systems microbiome and the cultured fish, as similar phytochemicals have been found to affect bacterial abundance and diversity and fish health and behaviour. These are key aspects to run aquaponics successfully, which shows the need for further investigation to better understand sources and mechanisms of such molecules and possible ways to harness beneficial effects that can guide new research directions as the role of aquaponics grows in recirculating aquaculture.

Rare report of bryozoan fouling of rock lobsters ( Jasus edwardsii : Decapoda: Palinuridae) from the North Island of New Zealand - Marcus M. Key; Abigail M. Smith; Benn Hanns; Pamela Kane‐Sanderson (New Zealand Journal of Marine and Freshwater Research, 2023)
Bryozoan epibiosis on lobster hosts is rarely reported. Here we document bryozoan fouling of the spiny rock lobster Jasus edwardsii from the Hauraki Gulf, North Island of New Zealand. The 92 lobsters in this study came from the Cape Rodney‐Okakari Point Marine Reserve. The lobsters were measured for size and weight, sexed, scanned for epibionts, and photographed. Forty‐two per cent of the lobsters were fouled by epibionts, but only 9% by bryozoans, and they were all males. The bryozoans were all cheilostome gymnolaemates. Only erect colonies were found on the dorsal carapace, and only encrusting colonies were found on the ventral surface. Two of the erect colonies were found in gaping exposed wounds through the exterior wall into the branchial chamber. In addition to host wounds, differences in frequency and location of fouling bryozoan colonies were also attributed to time since last moult and grooming. This epibiosis is interpreted as more of a one‐sided commensal symbiotic relationship, perhaps best described as phoretic (i.e. hitchhiking relationship).

A review of the nutritional requirements of chinook salmon ( Oncorhynchus tshawytscha ) - Bruno C. Araujo; Jane E. Symonds; Brett D. Glencross; Chris G. Carter; Seumas P. Walker; Matthew R. Miller (New Zealand Journal of Marine and Freshwater Research, 2023)
Chinook salmon ( Oncorhynchus tshawytscha ), also referred to as King salmon, is a premium aquaculture species farmed in New Zealand and to a small extent in western Canada. Despite the high research investment in the 50s and 60s, literature on nutrition on chinook salmon from recent years is sparse, particularly when compared to other salmonid aquaculture species, such as Atlantic salmon ( Salmo salar ) and rainbow trout ( Oncorhynchus mykiss ). To improve fish productivity, it is essential to provide specific and efficient diets based on satisfying chinook salmon requirements for nutrients and energy and adapting these to life‐stage, season, and production variables. Diet specifications for chinook salmon have to date largely been based on knowledge derived from other salmonid species and may not be optimised for chinook salmon. Thus, there is a lack of knowledge in some fundamental areas. This review explores the production status and literature related to the macro and micronutrient requirements, and general nutrition of chinook salmon. In doing so it compares these requirements to other farmed salmonids to understand some of the differences between species and highlights the main gaps in the literature.

Decadal changes in exploited fish communities and their relationship with temperature, fisheries exploitation, and ecological traits in New Zealand waters - Leonardo Maia Durante; Michael Peter Beentjes; Stephen Richard Wing (New Zealand Journal of Marine and Freshwater Research, 2023)
Composition and length‐frequency are important attributes considered in the management of fish communities and can be affected by both exploitation and environmental forces. Vulnerability to these effects varies among species depending on environmental tolerance, ecological traits, and life‐history strategies. In the present study, data from scientific bottom trawl surveys conducted between 1991 and 2018 were analysed to identify long‐term changes in community structure and length‐frequency of demersal fish species of the east coast of the South Island, New Zealand. Analysis of variance, hierarchical clustering analysis and multidimensional scaling relationships demonstrated that community composition has changed significantly over the last three decades, with a tendency towards greater spatial overlap among species in the most recent periods. Changes in depth distribution were identified but were mainly correlated with shifts in relative biomass. Total catch rate (kg km −2 ) of the whole community has increased significantly over time, while the average trophic level decreased, primarily explained by an increase in relative biomass of intermediate trophic level species. Fishing activity was significantly related to the variation in length‐frequency of species at intermediate trophic levels, confirming that the impacts of fisheries are heterogeneous throughout the community, providing vital information to support multi‐species management of fishery resources.

Occurrence of Perkinsus olseni and other parasites in New Zealand black‐footed abalone ( Haliotis iris ) - Farhana Muznebin; Andrea C. Alfaro; Stephen C. Webb (New Zealand Journal of Marine and Freshwater Research, 2023)
The culture of endemic New Zealand black‐footed abalone ( Haliotis iris ) represents a growing aquaculture industry, which is potentially threatened by pathogens and parasites. To identify and characterise health risks, a targeted sampling event was conducted of healthy‐ and unhealthy‐looking abalone (shell deformities, tissue damage and brown creamy substance/fluid in tissues) at a land‐based farm. Histological analysis showed signs of ill health, including disrupted and swollen gills with haemocytosis, ceroid material and parasites, and muscle tissues with focal haemocytosis with parasites. For the first time in H. iris , detailed histological observations, followed by confirmatory in situ hybridisation (ISH) resulted in the identification of Perkinsus olseni (5% prevalence). Scyphidia‐ like ciliates (56%), Sphenophrya‐ like ciliates (5%), unidentified disintegrated ciliates (26%), intracellular bacterial microcolonies (IMCs) (9%), apicomplexan‐like cells (1%) and bacteria (2%) were also identified across organs. There was a significant association between the presence of P. olseni and IMCs. Immunological tissue responses (haemocytosis and ceroid material) and gill pathology were evaluated semi‐quantitatively and were significantly associated with P. olseni . Gross abalone appearance was also significantly associated with P. olseni and unidentified disintegrated ciliates. These findings indicate the types of pathogens and parasites found in cultured H. iris for future health assessment studies of this important aquaculture species.

Freshwater migratory movements in a widely distributed New Zealand amphidromous fish Cheimarrichthys fosteri - Manna L. Warburton; Ryan R. Easton; Gerard P. Closs (New Zealand Journal of Marine and Freshwater Research, 2023)
Amphidromous fishes engage in migration to overcome the spatial mismatch between adult and larval habitat. The torrentfish ( Cheimarrichthys fosteri ), an endemic New Zealand amphidromous fish and only member of the Family Cheimarrichthyidae, display distinct spatial sexual segregation, but the migration assumed to overcome this segregation for reproduction is undocumented. We investigated the instream distribution of torrentfish, gaining insight into how barriers to reproduction are overcome, and how sex shapes migratory choices for the individual. We surveyed torrentfish at two spatial scales, examining the effects of sex and sexual maturity on distribution. We found that female torrentfish engage in prolonged upstream migrations, up to 100 km inland, with male torrentfish migrating upstream to a lesser extent. Both sexes return downstream to spawn, with males returning at the onset of maturity, while females may return and migrate back upstream, potentially making multiple downstream spawning migrations. Juvenile upstream migration likely results in competitive release and access to resources, but sets up a conflict between reproduction and transport of larvae into the nursery habitat in a timely manner. Adult downstream migration in torrentfish resolves this conflict and is similar to documented downstream spawning migrations in catadromous species.

Reproductive changes in Foveaux Strait Ostrea chilensis , Southern New Zealand, after Bonamia exitiosa epidemics - Samuel D. Heenan; Keith P. Michael; Daniel C. Smart; P. Mark Lokman; Miles D. Lamare (New Zealand Journal of Marine and Freshwater Research, 2023)
The commercially significant Foveaux Strait Ostrea chilensis fishery has been typified by consistently low brooding rates and recruitment failures since recurrent mass mortalities from Bonamia exitiosa infection. The present study examined the gametogenic cycle of Foveaux Strait O. chilensis monthly, from July 2017 to September 2018, using histological examination of the gonad and condition indices to determine resulting changes to gametogenesis, spawning, brooding, and spatial variation, compared to an initial study of reproduction before B. exitiosa epidemics. The seasonal gametogenic cycle and brooding period were similar to previous descriptions. However, there was evidence for a more female skewed sex ratio, and the development and release of ova into the mantle cavity at smaller sizes. Despite similarities in gametogenesis, sex ratios, temperature, and chlorophyll‐a concentrations between five sites across Foveaux Strait, the western‐most site had no brooders and consistently lower condition indices, compared to the eastern‐most site. Oysters may need to be in sufficient condition to initiate brooding, and reduced male densities may contribute to sperm limitation, which, along with a disconnect between the peak release of gametes and brooding, may have contributed to lower brooding rates.

Diversity of tropical macroalgae in the New Zealand marine aquarium trade - Kirill O. W. Woodhouse; Giuseppe C. Zuccarello (New Zealand Journal of Marine and Freshwater Research, 2023)
Exotic species often slip through international borders undetected. Increased global trade has increased the frequency of species introductions. The marine aquarium trade is a significant vector of species introductions, including algal introductions. Molecular barcoding of tropical macroalgae entering the New Zealand aquarium trade was implemented using various molecular markers. Both NCBI BLAST searches and maximum‐likelihood phylogenies were used to identify the isolates. A total of 62 species of tropical macroalgae were identified from coral rocks. Some species found are known as invasive elsewhere, for example, Caulerpa cylindracea , C. racemosa , C. sertularioides, Ulva ohnoi and Chaetomorpha vieillardii . All three major groups of algae were well represented with 26 species of red algae, 24 species of green algae and 12 species of brown algae. Temperature tolerance of some of these algae to minimum sea surface temperatures was tested. Results show that one species Chaetomorpha vieillardii can survive at Auckland minimum winter sea surface temperatures. Our findings have important implications for New Zealand biosecurity, as not only are a large diversity of exotic macroalgae entering the New Zealand marine aquarium trade unregulated, but there is also the potential for them to survive in New Zealand waters.

Issue Information (Reviews in Aquaculture, 2023)

Chinese abstracts (Reviews in Aquaculture, 2023)

Feed‐food competition in global aquaculture: Current trends and prospects - Anne‐Jo van Riel; Marit A. J. Nederlof; Killian Chary; Geert F. Wiegertjes; Imke J. M. de Boer (Reviews in Aquaculture, 2023)
Feed‐food competition is the allocation of resources that can be used to feed humans to animal feed instead, a current but unsustainable practise not well documented for aquaculture. Here, we analysed feed‐food competition in aquaculture using two measures; natural trophic levels (TLs) and species‐specific human‐edible protein conversion ratios (HePCRs). The HePCR equals the ratio of human edible protein in feed (input) to the human edible protein in animal produce (output). To provide prospects on aquaculture's potential to convert human inedible by‐products into edible biomass, data on aquaculture production were collected and categorized based on natural TLs. HePCRs were computed for four aquaculture species produced in intensive aquaculture systems: Atlantic salmon, common carp, Nile tilapia and whiteleg shrimp. Under current feed use, we estimated that the carp, tilapia and shrimp considered were net contributors of protein by requiring ~0.6 kg of human edible protein to produce 1 kg of protein in the fillet/meat. Considering soya bean meal and fishmeal as food‐competing ingredients increased the HePCR to ~2 and turned all of the case‐study species into net consumers of protein. To prevent this increase, the use of high‐quality food‐competing ingredients such as fishmeal, or soya bean products should be minimized in aquaculture feed. In the future, the role of aquaculture in circular food systems will most likely consist of a balanced mix of species at different TLs and from different aquaculture systems, depending on the by‐products available.

Agricultural wastes for brine shrimp Artemia production: A review - Nepheronia Jumalon Ogburn; Luchun Duan; Suresh Ramraj Subashchandrabose; Patrick Sorgeloos; Wayne O'Connor; Mallavarapu Megharaj; Ravi Naidu (Reviews in Aquaculture, 2023)
An increasing global population has meant aquaculture, one of the fastest growing food industry sectors, faces significant sustainability challenges as it tries to address the rising global protein demand. In many sectors, production is underpinned by fishmeal as dietary ingredient, but this is a finite resource with competing users from the poultry and livestock industries. Alternatively, some (planktonic) aquatic species, especially brine shrimp Artemia , can be produced using agricultural waste to provide food or biomass to support increasing aquaculture demand. This review investigates research and production of Artemia using agricultural waste. Various systems used for Artemia production in inoculated ponds are analysed and discussed to provide options for environmentally sustainable food systems that can be applied from either an artisanal level in developing countries with a considerable labour force, or in intensive systems in countries with large volumes of under‐utilised resources, for example, sugar/alcohol‐based waste and inland saline areas. Using agricultural waste, single cell protein production in a separate aerobic digester can be a simple, continuous food source for Artemia to enable daily biomass harvest. This could then be used as a fishmeal replacement or possibly for human consumption to promote a circular economy by remediating waste to produce protein, like a food production mine.

Portuguese‐Brazilian abstracts (Reviews in Aquaculture, 2023)

Arabic Abstracts (Reviews in Aquaculture, 2023)

Cover Image - Jie Wang; Limei Chen; Jian Xu; Shifeng Ma; Xiaofang Liang; Zuoxi Wei; Demao Li; Min Xue (Reviews in Aquaculture, 2023)

Spanish abstracts (Reviews in Aquaculture, 2023)

Circular and lower impact mussel and seaweed aquaculture by a shift towards bio‐based ropes - Leire Arantzamendi; Marga Andrés; Oihane C. Basurko; María José Suárez (Reviews in Aquaculture, 2023)
Worldwide, current mussel and seaweed aquaculture practices contribute to the increase of fossil fuel‐based plastic gears at sea, leading to marine litter and microplastics generation. Smart aquaculture has a great potential for shifting towards the use of lower impact bio‐based and biodegradable gears. This review defines the value chain of biogears as more sustainable gears for mussel and seaweed aquaculture, and sustainability issues covering technology, environmental impacts, economy‐market, policy, and social drivers for their potential implementation. Fit to purpose durability and functionality attributes, end‐of‐life (EoL) options and environmental benefits are key features for competitiveness of biogears versus conventional fossil fuel‐based aquaculture gears. EoL management for collection, sorting and logistics of biogears to recycling facilities is needed for the up cycling of bio‐based materials thus ensuring application of principles of circularity. The selection of the biopolymers for recyclability, improvement of the polymerisation and recycling processes together with the enhanced deployment of recycling facilities are considered as key factors for eco‐designing of circular biogears. Current policies supporting bio‐based plastics in marine applications and social benefits, as environmental sustainability, healthy products, and circular business opportunities, are likewise added value for the development and use of biogears. Overall, biogears can reduce environmental negative impacts in mussel and seaweed productions, while enabling circular use of bio‐based materials and sustainable circular bioeconomy.

Circular bio‐economy in aquaculture - Johan A. J. Verreth; Koushik Roy; Giovanni M. Turchini (Reviews in Aquaculture, 2023)

Biomass losses and circularity along local farm‐to‐fork: A review of industrial efforts with locally farmed freshwater fish in land‐locked Central Europe - Jan Mraz; Hui Jia; Koushik Roy (Reviews in Aquaculture, 2023)
Biomass losses and circularity of aquaculture farm‐to‐fork are reviewed in this article, taking the example of an economically developed but land‐locked territory in Central Europe. We found that some waste valorization channels of locally farmed and slaughtered fish biomass are already functioning in the region (mostly for pet food, hunting bait). There is neither control nor information on how much local aquaculture farm‐to‐fork losses are upcycled to the local human food chain. Despite most of them qualify in ‘category‐3’ animal by‐products (useable for aquafeed) or preventable losses. Factors to improve farm‐to‐fork resource use efficiency ‘locally’ include: (a) ‘at farm’ (supplementary feeding, captive culture conditions, fat content, breed, rested harvest techniques, harvesting season); (b) ‘towards fork’ (purging duration, acclimatization before slaughtering, stunning efficacy, bleeding and filleting relative to rigour mortis, additive‐based cleaning, pre‐cooling, boned or deboned, grinding or baadering); (c) ‘at fork’ (coating‐ or GRAS additives‐based preservation, packaging, modern hurdle systems, freezing rate, interferences of freezing apparatus or packaging on freezing, storage temperature). From farm‐to‐fork, it is essential to understand that most fish processing by‐products can be made edible or valuable by other means. Better utilization strategies exist via low‐cost value‐added fish products, innovative dishes or utility products (e.g., feedstuff, fertilizers, industrial products, luxury items). Although upcycling to human food chain is priority, technological hurdles (prone to spoilage, bones in product, taste, safety) are associated with edible products but are solvable. More difficult things to overcome are at the fork (culinary industry, communication with society, future generations). Those are reviewed.

Valorization of waste materials from seaweed industry: An industry survey based biorefinery approach - Jin‐Ho Yun; Stephen D. Archer; Nichole N. Price (Reviews in Aquaculture, 2023)

Review of waste phosphorus from aquaculture: Source, removal and recovery - Guozhi Luo (Reviews in Aquaculture, 2023)
The contribution of phosphorus to water body eutrophication is a global environmental problem, and rapid increases in aquaculture are considered a significant source of phosphorus discharged into the environment. The current review focuses on the source of aquaculture waste phosphorus and measures to decrease phosphorus release into the environment. Because diets are a significant source of phosphorus in fed aquaculture systems, improving the utilization efficiency of dietary phosphorus can reduce the amount of waste phosphorus at the source. A wide range of removal and recovery technologies has been identified, including adsorption, crystallization, enhanced biological phosphorus removal (EBPR), denitrifying phosphorus removal, heterotrophic nitrification aerobic denitrification (HAND) and photosynthetic organism removal. Recovery technologies were also reviewed, particularly sludge phosphorus from recirculating aquaculture systems. A new method using bacteria to immobilize waste nitrogen and phosphorus into bioflocs has been proposed as a better solution. However, most of these technologies have only been implemented at the lab scale to pilot scale. Further studies are necessary to determine the working conditions and removal capacities of related technologies on a commercial scale. Moreover, phosphorus removal methods must be selected based on a consideration of recyclability.

Towards achieving circularity and sustainability in feeds for farmed blue foods - Stefanie M. Colombo; Koushik Roy; Jan Mraz; Alex H. L. Wan; Simon J. Davies; Sean M. Tibbetts; Margareth Øverland; David S. Francis; Melissa M. Rocker; Laura Gasco; Emma Spencer; Marc Metian; et al. (Reviews in Aquaculture, 2023)
The aims of this review are to describe the role of ‘blue‐food production’ (animals, plants and algae harvested from freshwater and marine environments) within a circular bioeconomy, discuss how such a framework can help the sustainability and resilience of aquaculture and to summarise key examples of novel nutrient sources that are emerging in the field of fed‐aquaculture species. Aquaculture now provides >50% of the global seafood supply, a share that is expected to increase to at least 60% within the next decade. Aquaculture is an important tool for reducing resource consumption in global protein production and increasing resilience to climate change and other global disruptions (i.e. pandemics, geo‐political instability). Importantly, blue foods also provide essential nutrition for a growing human population. Blue foods are helping to help the global goal of ‘zero hunger’ (United Nation's Sustainable Development Goal 2) while reducing the dependency on finite natural resources but further refinement and new solutions are needed to make the industry more ‘circular’ and sustainable, particularly with respect to sourcing raw materials for aquafeeds. This review describes the feed resources that are available or may be created within a circular bioeconomy framework, their role within the framework and in aquaculture and ultimately, how these resources contribute to de‐risking and establishing a resilient aquaculture production chain.

Actinomycetes as a promising candidate bacterial group for the health management of aquaculture systems: A review - Kadayil Sachith Sunish; Krishnan Sreedharan; Shahmahal Kuniyil Shadha Nazreen (Reviews in Aquaculture, 2023)
Aquaculture is one of the most important economic activities in the world. However, the intensification of culture practices resulted in the emergence of various diseases caused by microorganisms and non‐infectious diseases caused mainly by the deterioration of water quality. Several prophylactic and treatment options have been exploited over the years to tackle the disease problem in aquaculture. Previously, antibiotics have been used indiscriminately for treating many fish diseases which resulted in the emergence of antimicrobial resistance. To overcome the failure of existing management strategies, innovative antimicrobial drug research is crucial and actinomycetes have proven to be trustworthy sources of new antimicrobial chemicals and are one of the most economically and biotechnologically important bacteria with multitude of functions. This review updates and highlights the role of actinomycetes in encouraging sustainable aquaculture practices and identifies opportunities for additional research and development. Many genera of actinomycetes were found to enhance the growth and survival of cultured species by producing many nutritional factors. They also improve the water quality of culture systems by the production of hydrolytic enzymes. Actinomycetes were found to improve the immunity of aquatic organisms by augmenting many immune parameters and making them more resistant to infection. Many actinomycetes have been discovered to produce antagonistic substances and exhibited antibacterial, antiviral, antibiofilm and anti‐quorum sensing activities. Probiotic potential of many actinomycetes has been widely explored. Even though actinomycetes have been widely used in aquaculture for multi purposes, the exact mechanism of action of these bacterial groups is poorly understood and novel biotechnological tools can be used for unravelling this.

Potential of innovative marine aquaculture techniques to close nutrient cycles - Ricarda Lothmann; Hani Sewilam (Reviews in Aquaculture, 2023)
Aquaculture is an established technique for producing marine species. However, it creates large amounts of nutrient‐rich waste. Therefore, it is worth examining the methods available to use these nutrients and close the nutrient cycle. This review covers research activities of different saline water methods for food production. These are Integrated Multi‐Trophic Aquaculture (IMTA), Biofloc Technology (BFT) and marine aquaponics. IMTA combines on‐ and offshore aquaculture with macroalgae and filter feeder production. Commercial implementations have been achieved but are not widely used. Especially shrimp are suitable for cultivation in saline BFT systems. Few commercial deployments exist. There is a well‐established market for the products of IMTA and BFT systems. Marine aquaponics is increasingly being tested as part of an expansion of Recirculating Aquaculture Systems (RAS) and BFT systems, but commercial implementations are not known. Moreover, there is no established market for the resulting salt‐tolerant plants (halophytes). Market prices and popularity were evaluated to assess the economic potential of the different plant and aquaculture species farmed with IMTA, BFT and marine aquaponics. There are established markets for well‐known products, but therefore the competition is greater. Niche products are offered occasionally, but often achieve top prices. Closing nutrient cycles and increasing saline water usage for food production as well as high product diversity are necessary to mitigate the increasing pressure on freshwater resources and to be able to feed the growing world population. Therefore, IMTA, BFT and marine aquaponics are promising techniques for reducing pressure on freshwater resources and improving food supply.

C1 gas protein: A potential protein substitute for advancing aquaculture sustainability - Jie Wang; Limei Chen; Jian Xu; Shifeng Ma; Xiaofang Liang; Zuoxi Wei; Demao Li; Min Xue (Reviews in Aquaculture, 2023)
Aquaculture has been the fastest‐growing food production sector and is considered to be so in the future. However, aquaculture feed is heavily dependent on wild‐captured forage fish, which is unsustainable, costly and non‐ecofriendly. Hence, the development of sustainable, eco‐friendly, cost‐effective and nutrient‐balanced novel fishmeal alternatives is critical to satisfying the forecasted expansion of aquaculture. Among fishmeal alternatives, attention to one‐carbon gas protein (C1GP) has reached an unprecedented level recently. The C1GP is produced through the fermentation of certain unique microorganisms by utilizing the substrates from C1‐related industrial exhaust gases, such as CH 4 , CO and CO 2 , which take much less time, land, water and resources, remove greenhouse gases and waste materials, and offer sustainable protein sources. These C1GP products, either as fishmeal or soybean meal alternatives, have been successfully used in fish and shrimp diets. This review introduces the latest research progress on microorganisms, protein production technology, nutrition and products using C1 gases as substrate, as well as their application in aquafeed. With the rapid development of synthetic biotechnology and engineering technology, it will become an important development field in the future in the construction of new strains and gas fermentation technology with high transformation efficiency, wide adaptation and abundant nutrients for the development of new ingredients for aquaculture.

Understanding and approaches towards circular bio‐economy of wastewater reuse in fisheries and aquaculture in India: An overview - Shib Kinkar Das; Bithilekha Mondal; Uttam Kumar Sarkar; Basanta Kumar Das; Simanku Borah (Reviews in Aquaculture, 2023)
Circular bio‐economy of biogenic resources designates the plunging use of such resources, adopting a systemically formatted pathway towards sustainable economic development. Aquaculture has been perceived to play a pivotal role in supplying protein and mineral rich organic food to a growing human population. The exponential growth of aquaculture sector during the last four decades has established itself in a fundamental way to supply the global need of valuable animal protein. However, the on‐going production strategies may likely be proved unsustainable if the present level of exploitation and resource use continues. Emphasis only on augmenting productivity and yield with insufficient and/or inefficient pollution control measures, and water quality clean‐ups, direct discharge of effluents in the open ambient environment from aquaculture production systems have manifested in variable degrees of pollution particularly in the open water bodies; thereby causing significant impairment of these ecosystems. The paper discusses the various techniques of bioprocessing in re‐circulatory aquaculture system, aquaponics, biofloc technology, waste water aquaculture and circular enclosure culture for inland water bodies to recycle the waste generated from fisheries and aquaculture and converting the same to fish flesh, at the same time reducing the impact on environment. The study also highlights the potential attributes and benefits of circular bio‐economy, discusses recent advances and updates the current status of knowledge base for future research planning towards sustainability. Rationality perspectives of the system design with regards to simplicity, energy efficiency and budget in attaining circularity emerged as pertinent factors in bio‐circularity in resource use in aquaculture.

From the sea to aquafeed: A perspective overview - Orhan Tufan Eroldoğan; Brett Glencross; Lucie Novoveska; Susana P. Gaudêncio; Buki Rinkevich; Giovanna Cristina Varese; Maria de Fátima Carvalho; Deniz Tasdemir; Ivo Safarik; Søren Laurentius Nielsen; Céline Rebours; Lukić Bilela Lada; et al. (Reviews in Aquaculture, 2023)
Aquaculture has been one of the fastest‐growing food production systems sectors for over three decades. With its growth, the demand for alternative, cheaper and high‐quality feed ingredients is also increasing. Innovation investments on providing new functional feed alternatives have yielded several viable alternative raw materials. Considering all the current feed ingredients, their circular adaption in the aquafeed manufacturing industry is clearly of the utmost importance to achieve sustainable aquaculture in the near future. The use of terrestrial plant materials and animal by‐products predominantly used in aquafeed ingredients puts a heavily reliance on terrestrial agroecosystems, which also has its own sustainability concerns. Therefore, the aquafeed industry needs to progress with functional and sustainable alternative raw materials for feed that must be more resilient and consistent, considering a circular perspective. In this review, we assess the current trends in using various marine organisms, ranging from microorganisms (including fungi, thraustochytrids, microalgae and bacteria) to macroalgae and macroinvertebrates as viable biological feed resources. This review focuses on the trend of circular use of resources and the development of new value chains. In this, we present a perspective of promoting novel circular economy value chains that promote the re‐use of biological resources as valuable feed ingredients. Thus, we highlight some potentially important marine‐derived resources that deserve further investigations for improving or addressing circular aquaculture.

The biofouling process: The science behind a valuable phenomenon for aquaculture - Estefanía Garibay‐Valdez; Luis Rafael Martínez‐Córdova; Francisco Vargas‐Albores; Maurício G. C. Emerenciano; Anselmo Miranda‐Baeza; Edilmar Cortés‐Jacinto; Ángel M. Ortiz‐Estrada; Francesco Cicala; Marcel Martínez‐Porchas (Reviews in Aquaculture, 2023)
Biofouling, the biological process leading to the accumulation of microorganisms, has been promoted for over a decade in aquaculture, particularly in biofloc technology, biofilm‐based systems and recently aquamimicry. However, the science behind biofouling is largely unknown in aquaculture. This document brings the science behind the biofouling process, reviews and analyses available information about the different phases of such a unique natural process. In aquatic or high humidity environments, substrata rapidly become colonized by microbes. After molecules form a thin film on any surface, bacterial adhesions occur and bacteria–bacteria, bacteria–eukaryotes and bacteria–substrate interactions take place; bacterial adhesion entails the production of adhesins and polysaccharides production. Coaggregation continues after irreversible adhesion, but the activated genes during the adhesion process associated with flagella and pili are suppressed in this stage. Throughout the process, bacteria communicate by excreting signalling or self‐inducing molecules, and other bacteria recognize these molecules that serve as a sort of checkpoint associated with their accumulation. Thereafter, the maturation phase is achieved and usually characterized by a colony equilibrium; some bacteria and other microorganisms achieve prominence in the colony, and many of the members have their functions and contributions to the microbial community. Finally, the detachment involves a complex but coordinated process involving several environmental signals, signal transduction pathways and effectors, promoting biofilm or biofloc split and dispersal to start the process again. In conclusion, biofouling is a complex, multifaceted process, but a deeper understanding of it and its consequent regulation would benefit microorganism‐based aquaculture.

Insect rearing on biowaste represents a competitive advantage for fish farming - Josef Maroušek; Otakar Strunecký; Anna Maroušková (Reviews in Aquaculture, 2023)
Feeding cost is among the main drivers in the price competitiveness of intensively‐fed‐aquaculture (IFA) products. As soaring energy prices increase the costs of technologies used to increase the digestibility of plant protein feeds, there is an urgent call for comprehensive knowledge on the mass use of insects as fish feed. This review identifies the key aspects of insect incorporation into established IFA practices and puts them into a commercial context. Larvae of Black soldier fly (BSFL) is identified as the most versatile in terms of (a) variety of biowaste usable for its rearing, (b) automatization and scaling up, (c) nutritional value and (d) circular and environmental aspects. Furthermore, modifications insect diets can increase the levels of valuable compounds such as omega‐3 fatty acids in fish. Other insects such as ants or mealworms have the potential to meet the nutritional requirements of various fish species. While today the production costs of BSFL (mostly around 3.5 € kg −1 ) are mostly determined by labour costs, it is predicted that intensified industrialization of insect rearing could reduce the production cost below 2 € kg −1 . In addition, multiple positive economic impacts, as well as environmental spillovers, have been identified. It is proposed that further research should be directed towards the refining and further valorization of byproducts from insect farming which could further dissolve the rearing cost. Bringing the IFA into compliance with the principles of the circular economy increases its competitiveness by reducing production costs and improving public opinion.

Influence mechanisms of macro‐infrastructure on micro‐environments in the recirculating aquaculture system and biofloc technology system - YunPeng Zhao; Boru Xue; Chunwei Bi; Xiaozhong Ren; Ying Liu (Reviews in Aquaculture, 2023)
Aquaculture intensification has emerged as a potential sustainable aquaculture strategy to contribute to the Food and Agriculture Organisation's United Nations Sustainable Development Goals associated with food security. Recirculating aquaculture systems (RASs) and biofloc technology systems (BFTs) are typical land‐based intensive aquaculture facility models that have been widely researched and applied. The rapid growth of both systems has boosted human nutrition and the regional economy but has also caused concerns about animal welfare, ecological protection, water treatment effectiveness and public health. One of the key links between aquaculture and ecological issues is the treatment of harmful particulates in wastewater, particularly organic metabolic microparticles. These microparticles are derived from decomposition waste feed, faeces and biofilm and provide a surface for bacterial growth and proliferation. The increase in microparticle abundance can directly affect bacterial activity and abundance and adversely affect the environment. Furthermore, the decomposition and motion of these particles are related to the mechanical stress caused by the water flow pattern in aquaculture tanks. The internal configurations of the tank can control the hydrodynamic characteristics, such as the water velocity, uniformity, pressure and turbulence in aquaculture tanks, and thus influence the morphology of particles. This review analyses and discusses how macro‐infrastructure influences the microenvironment in aquaculture tanks. These results provide a theoretical foundation and practical implications for improving the performance of aquaculture systems and environmental management in intensive aquaculture. It is concluded that optimisation of infrastructure design is key to improving the water flow patterns and self‐cleaning performance of tanks and achieving high efficiency of RASs and BFTs, and is critical for the fulfilment of the Sustainable Development Goals in aquaculture.

Size structure of broadnose sevengill sharks ( Notorynchus cepedianus ) in Sawdust Bay, Rakiura/Stewart Island, estimated using underwater stereo‐photogrammetry - Robert Lewis; Steve Dawson; Will Rayment (New Zealand Journal of Marine and Freshwater Research, 2023)
The broadnose sevengill shark ( Notorynchus cepedianus ) is a large marine predator found in temperate coastal marine habitats. Despite being commonly encountered, details of its ecology are limited. To partially address this, we quantified the size and sex structure of N. cepedianus in Paterson Inlet, Stewart Island, New Zealand. A stereo‐camera baited underwater video system (BRUV) was deployed in a shallow coastal embayment to capture underwater video of N. cepedianus for stereo photogrammetric measurement between June 2016 and November 2017. Individual sharks were sexed via observation of claspers. Three‐dimensional underwater calibration of the photogrammetric system, using a precisely measured cube, indicated a mean error of n = 78 individuals, mean = 211.4, S.E. = 2.97). The observed sex ratio was heavily biased, with females making up 95% of the population in winter 2016 and 73% in summer 2017. This study provides new data on N. cepedianus in southern New Zealand as well a non‐invasive, low‐cost methodology that can be applied to other study areas.

Discovery of a host fish species for the threatened New Zealand freshwater mussel Echyridella aucklandica (Bivalvia: Unionida: Hyriidae) - Michele Melchior; Nicole J. Squires; Susan J. Clearwater; Kevin J. Collier (New Zealand Journal of Marine and Freshwater Research, 2023)
Larvae (glochidia) of Unionida mussels form obligate symbiotic associations with host fish to complete their life‐cycle. To identify previously unknown host fish associations for the threatened New Zealand Echyridella aucklandica , glochidia infestation on fish by two mussel species was quantified in four Waikato streams. A host for E. aucklandica was identified for the first time, with glochidia found to attach and encyst on the common smelt Retropinna retropinna but not on other fish species caught. In contrast, E. menziesii was found on a range of fish species but not on the two R. retropinna caught. Encysted E. aucklandica glochidia showed evidence of growth on the gills of host fish. These preliminary results provide critical knowledge of host–glochidia interactions in sympatric New Zealand unionid species to support integrated conservation management targeting both unionid communities and host fish populations.

Multi‐decadal observations of the size structure of sperm whales at Kaikōura, New Zealand - Toby Dickson; William Rayment; Marta Guerra; Steve Dawson (New Zealand Journal of Marine and Freshwater Research, 2023)
Measurements of body length play an important role in the assessment of size and population structure of whales, allowing estimation of population parameters such as age at sexual and physical maturity. Uniquely, sperm whales can be measured from the interpulse interval (IPI) of their echolocation clicks, which contain information on the length of the head, which is allometrically related to body length. Measurements of IPI were taken from 424 acoustic recordings made between 1996 and 2019 at Kaikōura, New Zealand. Extrapolation to total length, using a new regression equation calculated from this population, revealed a significant increase in the mean length of whales visiting Kaikōura during summer in recent years (2014–2019), with no trend in the mean length for those visiting in winter. Increasing size during summer months appears to be driven by the growth of the same individuals returning summer after summer, combined with declining recruitment of new, smaller individuals. Thus, we hypothesise that the whales that visit in summer may represent an aging population. This is significant as sperm whales are a taonga [Of special significance to NZ Māori] species, top predators in the Kaikōura ecosystem, and the primary focus of the tourism industry at Kaikōura.

Two new cryptic species of the freshwater fish genus Gobiomorphus (Gobiiformes: Gobioidei: Eleotridae) in New Zealand - Christine E. Thacker; Daniel L. Geiger; James J. Shelley (New Zealand Journal of Marine and Freshwater Research, 2023)
We describe two new species in the genus Gobiomorphus , a radiation of fresh and brackish water gudgeons known from Australia and New Zealand. These species are a prominent component of New Zealand's freshwater ichthyofauna and most are widely distributed throughout both the North and South Islands. Two of the inland species, G. breviceps and G. basalis, are composed of disjunct northern and southern populations that are distinguishable with molecular data . We examine individuals from across the ranges of both species, identify morphological differences between them, and describe two new species: Gobiomorphus dinae n. sp. (distinct from G. basalis ) and Gobiomorphus mataraerore n. sp. (distinct from G. breviceps ). Although the species are similar, they vary in dorsal spine count ( G. dinae ) and pectoral fin ray count ( G. mataraerore ). We provide mitochondrial COI sequences for each species pair to facilitate identifications by DNA barcoding. These species represent examples of divergence in allopatry, with diagnostic characters arising over the last 2−5 million years in the G. breviceps/G. mataraerore pair, and fewer than 2 million years in the G. basalis/G. dinae pair. We also designate a lectotype for G. basalis (the paralectotype is G. cotidianus ) in order to clarify confusion surrounding the original syntypes.

Pup numbers, estimated population size, and monitoring of New Zealand fur seals in Doubtful/Pateā, Dusky and Breaksea Sounds, and Chalky Inlet, Fiordland, New Zealand 2021 - B. Louise Chilvers (New Zealand Journal of Marine and Freshwater Research, 2023)
New Zealand fur seals ( Arctocephalus forsteri ) are expanding in numbers and distribution throughout New Zealand. The exception is the West Coast of the South Island, where there is documented decline due to decades of mortalities related to fishery. There are fur seal colonies south of these West Coast colonies, in Fiordland, which have never been accurately documented or monitored. Even for those that are documented, there are few records of pup numbers and no population estimates. Here, pups at colonies from Doubtful/Pateā, Dusky, and Breaksea Sound, and Chalky Inlet were observed, and their numbers either counted directly or estimated using mark‐recapture methods in February 2021. From these pup counts a coarse minimum population estimate of between 14–24 thousand fur seals is calculated for lower Fiordland. The pup counts and population estimates indicated the fur seal numbers are higher than previously recorded from estimates of walk through, boat or helicopter observations. During onshore surveys and from anecdotal evidence, it was noted that fur seals were rearing pups in forested areas. This paper outlines suggestions for the future monitoring of these colonies given, location, diverse geology and the difficulty of monitoring colonies on exposed west coast areas of New Zealand's Fiordland.

Modelled effects of channel orientation and tree canopy shape on average shade in streams - James Christopher Rutherford; Sandy Haidekker; Fleur E. Matheson; Andrew Hicks (New Zealand Journal of Marine and Freshwater Research, 2023)
Replanting riparian vegetation can improve ecological health but there are few guidelines that help stakeholders achieve shade targets cost‐effectively. A computer model was extended to calculate average shade to direct and diffuse solar radiation in straight channels. It was used to recommend strategies for achieving shade targets, including the 70% guideline shown to prevent nuisance aquatic plant growths and extreme water temperatures. For similar trees on both banks, 70% shade occurs when the ratio of tree height (H) to stream width (W) lies in the range 1.0

Spawning runs of naturalised rainbow and brown trout from Lake Otamangakau, central North Island, New Zealand - Michel Dedual (New Zealand Journal of Marine and Freshwater Research, 2023)
This study describes some of the characteristics of the spawning runs of rainbow and brown trout from Lake Otamangakau, into Te Whaiau Stream. More than 55,000 fish undergoing spawning migrations were enumerated in a fish trap between 1994 and 2013. During that period, the spawning run size increased for both species, but particularly for rainbow trout, which exhibited a concurrent decline in average weight. The timing of the runs was consistent across both species, sexes, and maturation statuses but was affected by the average weight of the fish and the run size. The level of iteroparity revealed that 40% and 55% of the runs were made up of previous spawner rainbow and brown trout, respectively. Detections of PIT‐tagged fish at the trap indicated that rainbow and brown trout could spawn up to six and eight times, respectively. Remarkably, repeat spawning fish of both species and sexes returned within a few days of the same date each year over consecutive spawning events. Rainbow and brown trout grew substantially after spawning up to the 3rd and 4th spawning, respectively. The results of this study are relevant for informing management of the popular Lake Otamangakau trout fishery, in particular achieving a balance between satisfactory CPUE and large fish size.

Growth and diet of inanga ( Galaxias maculatus ) within a small New Zealand coastal pond system - Rose E. Stuart; Travis Ingram; Gerard P. Closs (New Zealand Journal of Marine and Freshwater Research, 2023)
Inanga ( Galaxias maculatus ) are found in a range of freshwater habitats around much of the Southern Hemisphere. Although they are reasonably well studied within New Zealand, little is known about the populations found in coastal pond systems. This study focussed on inanga diet and population dynamics within a shallow pond complex in coastal Southland, investigating age, growth, distribution, and diet of juvenile inanga over a spring to autumn period. Otolith analysis indicated a three‐month period (September to November) during which fish are hatching, with fish that hatched earlier growing more slowly than later fish. Inanga were found in only one location within the pond complex – a site featuring low water nutrient levels and less access by trout. Diet analysis showed high selectivity for chydorids and chironomid larvae, indicating a mixture of both benthic and pelagic foraging. Overall, this study has provided insight into inanga population dynamics in ponds, which have not previously been observed.

Molecular detection and distribution of the genera Amphidoma and Azadinium (Amphidomataceae, Dinophyceae) in the coastal waters of Aotearoa/New Zealand - Muharrem Balci; Lesley L. Rhodes; Tomohiro Nishimura; J. Sam Murray; D. Tim Harwood; A. Lincoln MacKenzie; Tony Bui; Catherine Moisan; Lucy Thompson; Kirsty F. Smith (New Zealand Journal of Marine and Freshwater Research, 2023)
Molecular‐based approaches for harmful algal bloom species, which can be difficult to identify by light microscopy, are important tools for detecting and predicting the blooms. In this study, 84 samples from Aotearoa/New Zealand coastal waters that contained Azadinium ‐like cells were analysed using an Amphidomataceae real‐time PCR assay. Nineteen samples were positive, and 24 Azadinium ‐like clonal isolates were established from these samples. Subsequently, only five isolates from one sampling point were positive using the real‐time PCR assay. Four of the five isolates were genetically identified as Amphidoma languida and one as Azadinium dalianense . The field samples were analysed retrospectively using the species‐specific real‐time PCR assays; Am. languida was detected from the temperate areas, while Az. poporum and Az. spinosum were detected at one site. Two representative strains of each species were analysed by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS), including Am. languida, which is known as toxic in the previous studies, but neither produced the currently monitored azaspiracids (AZAs). These two newly recorded species for New Zealand are important findings. The results highlight the need for more information on the spatio‐temporal variations of potentially toxic Amphidomataceae species and the risk of AZAs in New Zealand coastal waters.

Riparian plant species offer a range of organic resources to stream invertebrate communities through varied leaf breakdown rates - Kristy Hogsden; Sophie O'Brien; Stacey Bartlett; Helen Warburton; Hayley Devlin; Kathryn Collins; Catherine Febria; Brandon Goeller; Angus McIntosh; Jon Harding (New Zealand Journal of Marine and Freshwater Research, 2023)
Riparian plants provide an important source of energy for freshwater food webs through inputs of leaf litter. Planting riparian buffers with mixed species could enhance the detrital resource supply for invertebrates through varied leaf breakdown rates. To quantify leaf breakdown rates and invertebrate colonisation, we used leaves from eleven grass, shrub and tree species common along agricultural waterways in New Zealand. Breakdown of leaves immersed in a spring‐fed stream differed significantly among species, being fastest for pasture grass ( k = 0.0458 day −1 ) followed by broadleaf, pittosporum, willow, toetoe, poplar, gorse, Carex , eucalyptus, flax, and slowest for cabbage tree leaves ( k = 0.0099 day −1 ). Invertebrate community composition did not differ between leaf species, but consumers were extremely abundant on some leaves (e.g. 51–83 Potamopyrgus snails g −1 pasture grass), indicating coarse detrital resources were in high demand for food or habitat. These breakdown rates could inform selection of riparian plant combinations that will enhance food availability for stream communities, especially continuity of supply, thereby contributing to waterway restoration.

Portuguese‐Brazilian abstracts (Reviews in Aquaculture, 2023)

Issue Information (Reviews in Aquaculture, 2023)

Aquaculture sustainability: Global challenges need local actions - Giovanni M. Turchini (Reviews in Aquaculture, 2023)

Arabic abstracts (Reviews in Aquaculture, 2023)

Spanish abstracts (Reviews in Aquaculture, 2023)

Cover Image - Huijie Chen; Daji Luo (Reviews in Aquaculture, 2023)

Chinese abstracts (Reviews in Aquaculture, 2023)

Diseases of the giant river prawn Macrobrachium rosenbergii : A review for a growing industry - Chantelle Hooper; Partho P. Debnath; Grant D. Stentiford; Kelly S. Bateman; Krishna R. Salin; David Bass (Reviews in Aquaculture, 2023)
The giant river prawn, Macrobrachium rosenbergii , is a major focus of aquaculture in tropical and sub‐tropical regions around the globe. Over the last 30 years, culture of M . rosenbergii has increased exponentially as demand has risen both for domestic consumption and for international export trade. As with many aquaculture species increases in production have been accompanied by the emergence of diseases affecting yield, profit and trading potential. Disease‐causing agents include pathogens infecting other crustaceans, such as Decapod Iridescent Virus (DIV1), as well as pathogens only known from M . rosenbergii such as White Tail Disease caused by Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV). Here, we review the pathogenic agents associated with the culture of M . rosenbergii since commercial culture began in earnest during the 1970s. Particular emphasis is given to pathogens first identified in other aquaculture host species, but which have subsequently been shown to infect and cause disease in M . rosenbergii . As polyculture of M . rosenbergii with other aquaculture species is common practice, including culture with other decapods, crabs and fish, increased pathogen transfer among these farmed species may occur as M . rosenbergii aquaculture increases in the future.

Correction to “The regulation of shrimp metabolism by the white spot syndrome virus ( WSSV )” (Reviews in Aquaculture, 2023)

Ammonia induced toxico‐physiological responses in fish and management interventions - Ashokkumar Jayasree Parvathy; Bini C. Das; Marathippallam Jamal Jifiriya; Tincy Varghese; Devika Pillai; Vattiringal Jayadradhan Rejish Kumar (Reviews in Aquaculture, 2023)
Intensification of aquaculture practices resulted in increased ammonia production in the culture systems. Lack of proper management of the culture system will result in elevated ammonia, which adversely affects the culture species. Moreover, with the ongoing global warming, fish metabolism and ammonia excretion are expected to increase. This, coupled with the hypoxic condition, exacerbates the severity of ammonia toxicity. Ammonia toxicity can alter the growth and the biochemical, physiological and immunological responses of fish. Several factors such as pH, temperature, salinity, dissolved oxygen, species and life stages of fish, physical activity, feeding and stress influence the toxicity of ammonia in fish. A proper understanding of these factors is a prerequisite for successful aquaculture. The physiological changes caused by the elevated ammonia hinder homeostasis that eventually increases their susceptibility to diseases. This review discusses ammonia toxicity in fish, factors affecting the toxicity and various physiological, haematological, histological and immunological responses induced by the elevated ammonia. Furthermore, the review summarizes various management and dietary interventions to mitigate ammonia and ammonia induced stress in aquaculture.

Potential implications of sperm DNA methylation functional properties in aquaculture management - Songpei Zhang; Yu Cheng; Pavlína Věchtová; Sergii Boryshpolets; Nururshopa Eskander Shazada; Sayyed Mohammad Hadi Alavi; Jacky Cosson; Otomar Linhart (Reviews in Aquaculture, 2023)
The biology of fish sperm, an important topic in the research of reproduction and fisheries from basic science to evolutionary and applied aspects, has implications for aquaculture management, fish breeding and biological conservation. The quality of spermatozoa plays a vital role in fish fertility, and directly affects the health and performance of offspring. Environmental factors that affect determinants of spermatozoa quality usually reflected in the DNA methylation pattern of the spermatozoa epigenome, which may change offspring's performance. The aim of the present study was to conduct a review on existing data about DNA methylation in fish spermatozoa as a biological tool for identifying the quality of offspring based on their phenotypes and performances. Furthermore, this study provides valuable knowledge from fundamental to applied sciences dealing with enhancement of breeding selection, fish reproduction and environmental adaptation. The review also describes the individual parts related to DNA methylation in fish, including overview of the methods which can be used to study DNA methylation, DNA methylation dynamics and epigenetic inheritance; identification of DNA methylation changes in sperm function in response to internal and external environment constraints, and potential relationships between DNA methylation and physiological regulation of spermatozoa quality determinants. Overall, the present study revealed that our knowledge about intergenerational inheritance of the performance and adaptability of fish through sperm DNA methylation is very limited, and no general conclusion could be approached from literature mostly due to non‐standardized experimental protocol or analytical tools.

Overview of global Gracilaria production, the role of biosecurity policies and regulations in the sustainable development of this industry - Vaibhav A. Mantri; Cicilia S. B. Kambey; Elizabeth J. Cottier‐Cook; Sara Usandizaga; Alejandro H. Buschmann; Ik Kyo Chung; Tao Liu; Calvyn F. A. Sondak; Zizhong Qi; Phaik Eem Lim; Nguyen Van Nguyen (Reviews in Aquaculture, 2023)
Gracilaria aquaculture is one of the fastest‐growing sectors, contributing to 10.5% of the global seaweed feed‐stock supply chain in 2019. It predominantly caters to food‐grade agar, animal feed and non‐food sector applications viz. biotechnology, biomedical and pharmaceuticals. It has witnessed a rapid expansion triggered by increased demand due to commodity trade. Biosecurity‐related issues are the key factors constraining its expansion, but are seldom addressed. The global gracilarioids aquaculture is dominated by China and other Asian countries, namely the Republic of Korea, Indonesia, the Philippines and Vietnam. This paper provides an assessment of their national biosecurity capacity, including current risk management strategies, policies and the implementation of existing regulations. It also highlights specific gaps in national policies and regulations, which can be addressed to improve their health management systems. Biosecurity management strategies, such as the provision of clear regulatory guidance, mechanisms for notifying disease and pest outbreaks, movement of live seaweed, risk assessment, stakeholder incentivisation and certification are recommended. Further, insights into the impending biosecurity measures to the emerging countries in this domain namely India and Malaysia are discussed. We suggest, implementing a uniform format of global integrated biosecurity measures across the Gracilaria aquaculture industry, but this requires organisational, operational and procedural changes, coupled with a cross‐sectoral application of risk analysis protocols. Despite one of the important seaweed aquaculture taxa, an overview of Gracilaria production, the role of biosecurity policy and regulation in the sustainable development of this industry was still lacking, this is the first global effort in this direction.

Innovation in the Norwegian aquaculture industry - Samson Afewerki; Frank Asche; Bård Misund; Trine Thorvaldsen; Ragnar Tveteras (Reviews in Aquaculture, 2023)
Global aquaculture production has grown very rapidly in recent decades. This is largely due to a number of innovations that has increased the control with the production process and competitiveness. These innovations come in a number of forms from radical new concepts to knowledge adaption from the terrestrial food production system. While there exist a number of studies investigating the impact of specific innovations, there are few studies that take a larger perspective on how innovations over time impacts an aquaculture industry or the innovation system that support these innovations. In this paper we review the innovation process in Norwegian salmon aquaculture industry from its infancy in 1970 until present. Of particular interest is the increasing complexity of the industry, and how most innovations are conducted by suppliers and not the aquaculture producers themselves. The insights are also of general interest in global aquaculture as salmon is among the species with the most advanced production technologies, but also a species where innovations are adapted to other species also in very different production systems.

Thermal biology of tambaqui ( Colossoma macropomum) : General insights for aquaculture in a changing world - Renan Diego Amanajás; Adalberto Luis Val (Reviews in Aquaculture, 2023)
In this study, we review the state of the knowledge regarding the thermal biology of tambaqui ( Colossoma macropomum ) with emphasis on reproductive, zootechnical, metabolic, physiological and molecular aspects, which may direct paths for new research. We observed an optimal range for performance of the species, since it grows and reproduces well between 25 and 32°C, though does not tolerate temperatures below 23°C. Temperatures above 30°C cause disturbances in the processes of reproduction and development of embryos and larvae of tambaqui. Its metabolism is influenced by the size of the animal, with greater oxygen consumption in smaller animals and at higher temperatures. Haematology is one of the most often investigated fields and shows an elevation of the analysed blood parameters according to elevation in temperature, which, above 35°C, seems to be harmful to animals. However, studies are needed that examine the relationships between temperature and nutritional aspects (protein, lipid and carbohydrate metabolism), the cellular responses, the relationship with other environmental parameters (pH, oxygen, dissolved organic carbon), pollutants, ionic regulation and excretion, aerobic metabolism, growth and reproduction under warm conditions (>32°C; +60 days). There is also the need to determine the thermal limits of the species as a function of different acclimation temperatures.

Effect of the temperature of activation medium on fish sperm quality: Impact on fertilization in vitro in aquaculture practice - Osvaldo Merino; Jennie Risopatrón; Iván Valdebenito; Elías Figueroa; Jorge G. Farías (Reviews in Aquaculture, 2023)
Motility is a key in spermatozoon function, determining semen quality and fertilizing capacity. Motility in fish spermatozoa occurs when they are diluted in a swimming solution, the adequacy of which is determined by factors which vary by species. Spermatozoon motility rate and velocity, as well as the duration of the motility period, are influenced by the temperature of the swimming medium. Increasing the temperature of the swimming medium has a significant negative effect on spermatozoa motility kinematics. It increases the metabolism rate of cells, causing a mismatch of energy resources and promoting changes in sperm movement. It also generates an increase in the production of reactive oxygen species (ROS) and thus oxidative stress, and moreover results in an inadequate capacity of antioxidant enzymes to protect the cell against the effects of oxidative stress induced by higher temperatures. The aim of this review is to update present knowledge about: mitochondria main source of ATP; the protein phosphorylation related to motility; epigenetic regulation of the temperature of the activation and the role of ion channels in regulation motility. These mechanisms involved in sperm motility are of vital importance in regulating fertilization, all of which can be influenced by the environment. We emphasize the importance of investigating spermatozoon mechanisms in depth, especially in the context of climate change which results in changing water temperatures. Our findings provide a better understanding of fish sperm physiology, and a biological foundation for the further development of spermatozoon motility investigation, and reproduction technologies.

Carotenoids modulate stress tolerance and immune responses in aquatic animals - Keng Chin Lim; Fatimah Md. Yusoff; Murni Karim; Fatin M. I. Natrah (Reviews in Aquaculture, 2023)
Aquaculture continues to expand swiftly and remains the fastest‐growing food industry worldwide amidst ever‐present threats from chronic stressors and emerging diseases. Nutrition plays a pivotal role in the profitability and viability of the aquaculture industry that steered a paradigm shift to therapeutic nutrition. Carotenoids, also termed tetraterpenoids, have garnered considerable attention owing to their therapeutic attributes and immeasurable health benefits, which incited a surge in global demand. These biological pigments are recognized to promote immune systems and antioxidant defence mechanisms in both aquatic vertebrates and invertebrates. This review brings forth existing scientific evidence and underscores the notable roles of carotenoids as biologically active constituents with anti‐stress and immunostimulatory potentials in farmed aquatic animals whilst explicating possible mechanisms of action. Empirical data unequivocally established the modulatory functions of carotenoids on endogenous antioxidant enzymes, innate and adaptive arms of the immune response, as well as the expression of multiple antioxidant and immune‐related genes. The comprehensive information presented is beneficial to deepen our understanding of the utilization of carotenoids as potent stress alleviators and immunostimulants in cultured aquatic animals, which is translated into improved health. Advancements in aquatic animal health and welfare could principally contribute to reconstructing a more sustainable aquaculture industry. This article may be useful for subsequent investigations towards further advances in research and innovation to a greener blue revolution in solving the challenge of global food security.

Genome‐wide association and genomic selection in aquaculture - José M. Yáñez; Agustín Barría; María E. López; Thomas Moen; Baltasar F. Garcia; Grazyella M. Yoshida; Peng Xu (Reviews in Aquaculture, 2023)
Recent advancements in genomic technologies have led to the discovery and application of DNA‐markers [e.g. single nucleotide polymorphisms (SNPs)] for the genetic improvement of several aquaculture species. The identification of specific genomic regions associated with economically important traits, using, for example, genome‐wide association studies (GWAS), has allowed the discovery and incorporation of markers linked to quantitative trait loci (QTL) into aquaculture breeding programs through marker‐assisted selection (MAS). However, most of the traits of economic relevance are expected to be controlled by many QTLs, each one explaining only a small proportion of the genetic variation. For traits under polygenic control, prediction of the genetic merit of animals based on the sum of effects at positions across the entire genome (i.e. genomic estimated breeding values, GEBV, which are used for what has become known as genomic selection), has been demonstrated to speed the rate of genetic gain for several traits in aquaculture breeding. The aim of this review was to provide an overview of the development and application of genomic technologies in uncovering the genetic basis of complex traits and accelerating the genetic progress in aquaculture species, as well as providing future perspectives about the deployment of novel molecular technologies for selective breeding in coming years.

Two‐level trout supply chain's economic efficiency analysis in Iran: Trout egg import subsidies role - Hiva Asadikia; Seyed Habibollah Mosavi; Michael R. Reed; Trond Bjorndal; Hamed Najafi Alamdarlo; Sadegh Khalilian (Reviews in Aquaculture, 2023)
Iran has subsidised trout egg imports due to the lower feed conversion ratio of most imported trout eggs. However, the rainbow trout industry is divided on whether to allocate or abolish imported trout subsidies. The elimination of such support would lead to a three‐fold rise in the price of imported trout eggs (which are already more expensive than domestic trout eggs). Furthermore, the economic performance of the domestic trout supply chain over the imported trout supply chain remains yet to be clarified. The present study seeks to evaluate whether imported trout egg subsidies should be continued. Economic efficiency and network data envelopment analysis are used to evaluate the performance and role of subsidies in trout supply chains in Mazandaran, one of the largest trout farming provinces as a new case study in the aquaculture sector, in 2018. Farms that used imported trout eggs were found to have lower economic efficiency and higher dependence on import subsidies. Feed costs were identified to be the most important explanation for poor economic efficiency of trout production. Finally, the results reveal that the development of domestic trout propagation supply chains with integrated forward vertical structures could improve efficiency in the system. The re‐distribution of imported trout egg subsidies to fund feed cost reduction technologies could provide effective solutions to enhance economic efficiency, production sustainability and food security.

Nanotechnology in reproduction, breeding and conservation of fish biodiversity: Current status and future potential - Irfan Ahmad Bhat (Reviews in Aquaculture, 2023)
The reproductive capability of an organism is the main factor to determine the stability of the population. Till now, numerous reproductive strategies have been used, to successfully breed the fish in captivity but the desired performance is yet to be achieved. Nanotechnology has transformed the reproductive capacity of higher animals to a greater extent and has a huge potential in the aquaculture sector too. The use of nanotechnology in fish reproduction and breeding is limited to the delivery of drugs, hormones, vaccines, or genes and still, an immense scope is left in the area that needs to be explored. Here, the recent progress of nanotechnology in fish reproduction, breeding and conservation of germplasm is reviewed. Further, the key successes in the development of cryopreservation, semen imaging, sperm sorting, germplasm preservation, prototypes of smart nanobiosensors and drug delivery systems in animals including fish are highlighted. The potential future opportunities for nanotechnology to enhance reproductive output and conservative management of fish have been presented. In general, the current review summarises some of the applications of nanotechnology that are performing well in higher animals and could be a game‐changer in manipulating the reproductive potential or conserving the fish germplasm.

From the AKAP to AKAIE model to assess the uptake of technological innovations in the aquaculture sector - Yari Vecchio; Margherita Masi; Felice Adinolfi (Reviews in Aquaculture, 2023)
The purpose of this study is to explore the adoption of innovation in the aquaculture sector through the Awareness Knowledge Adoption Implementation Effectiveness (AKAIE) sequence. The AKAIE is an extension of the Awareness Knowledge Adoption Product (AKAP) model in order to better investigate the post‐adoption phases. Using the ‘ Implementation ’ and ‘ Effectiveness ’ phases, this study aims to further the understanding of both the different levels of adoption and the impact of innovation in terms of environmental, economic and social benefits produced. The proposed sequence is contextualised in light of the multidimensional scenario of on‐farm and off‐farm factors acting alongside the adoption of new technologies in the aquaculture sector. In this paper, the perspective of aquaculturists is represented with the concept of perceived complexity as the central node of the adoption process. The proposed tool could support policy makers in understanding and disseminating innovation in aquaculture.

Application of haematology parameters for health management in fish farms - Huijie Chen; Daji Luo (Reviews in Aquaculture, 2023)
Farmed fish are a promising source of high‐quality and sustainable protein. However, the production of farmed fish products that meet food safety standards is one of the major public health challenges worldwide. Therefore, food safety management in fish farms has recently garnered increasing attention. However, the detection of health parameters in fish is currently lacking. Haematology, an approach that is widely used in humans, provides a reliable assessment of health status in a non‐lethal and low‐cost way. Nevertheless, comprehensive, systemic and standard haematological parameters have not yet been established in farmed fish. Here, we provide a summary of the recent advancements in haematology health indicators in fish. Generally, haematological parameters are based on physiological and biochemical indices in blood. After a global review of haematology in fish, we analysed the research progress and current trends in haematology indicators in farmed fish, and explored their potential application for healthy farming. Furthermore, we discuss the internal and external environmental factors that also affect blood physiological and biochemical indices. Finally, we discuss the trends and future challenges for the application of haematology in fish. Collectively, the topics discussed in this review highlight the predictive and severely underrated value of haematological parameters in fish farming.

Deep learning for visual recognition and detection of aquatic animals: A review - Juan Li; Wenkai Xu; Limiao Deng; Ying Xiao; Zhongzhi Han; Haiyong Zheng (Reviews in Aquaculture, 2023)
The ocean is an important ecosystem, and aquatic animals play an important role in the biological world, especially in aquaculture. How to accurately and intelligently recognise and detect aquatic animals is one of the urgent problems in the field of underwater biological detection. The wide applications of artificial intelligence (AI), especially deep learning (DL), provide new opportunities and challenges for the efficient and intelligent exploration of aquatic animals. DL has been widely used in the visual recognition and detection of terrestrial animals, but it is in the early stages of use for aquatic animals due to the complexity of underwater environment and the difficulty of data acquisition. Here, this article reviews the current application status of DL for aquatic animals, potential challenges and future directions. The key advances of DL algorithms applied to the visual recognition and detection of aquatic animals are generalised, including datasets, algorithms and performance. The applications of DL are summarised in aquatic animals, including image detection, video detection, species classification, biomass estimation, behaviour analysis and food safety. Furthermore, the challenges are summed up and classified in the object recognition and detection domain for aquatic animals. Finally, further research direction is discussed and the conclusions are drawn. The key advances of DL in the recognition and detection of aquatic animals will help to further excavate and extend the application of DL in the field of marine biological exploration.

An assessment of the aquaculture potential of indigenous freshwater food fish of Fiji, Papua New Guinea, Vanuatu, Solomon Islands, Samoa and Tonga as alternatives to farming of tilapia - Monal M. Lal; Kelly T. Brown; Prerna Chand; Timothy D. Pickering (Reviews in Aquaculture, 2023)
An important driver behind introductions for aquaculture of alien fish species into Pacific Island Countries and Territories (PICTs) is a lack of knowledge about domestication suitability and specific culture requirements of indigenous taxa. Introductions may be appropriate in some circumstances, but in other circumstances, the associated risks may outweigh the benefits, so greater understanding of indigenous species' aquaculture potential is important. This review summarises literature for indigenous freshwater food fish species from Papua New Guinea, Fiji, Vanuatu, the Solomon Islands, Samoa and Tonga, and evaluates their aquaculture potential for food security and/or small‐scale livelihoods. A species selection criteria incorporating economic, social, biological and environmental spheres was used to score 62 candidate species. Tilapia ( Oreochromis mossambicus and O . niloticus ) now established in PICTs were evaluated for comparison. Results show that 13 species belonging to the families Mugilidae (Mullets), Terapontidae (Grunters), Kuhliidae (Flagtails) and Scatophagidae (Scats) have the highest culture potential according to selection criteria. These feed at a relatively low trophic level (are herbivores/detritivores), have comparatively fast growth rates and overall possess characteristics most amenable for small‐scale, inland aquaculture. The four top‐ranked candidates are all mountain mullets Cestraeus spp., followed by Nile tilapia ( Oreochromis niloticus ). Lower ranked candidates include three other mullets ( Planiliza melinoptera , P . subviridis and Mugil cephalus ) and rock flagtail Kuhlia rupestris . Importantly, many species remain data deficient in aspects of their reproductive biology or culture performance. Species profiles and ranked priority species by country are provided with logistical, technological and environmental assessments of country capacities to culture each species.

Fish disease prevention via microbial dysbiosis‐associated biomarkers in aquaculture - Julia Mougin; Alyssa Joyce (Reviews in Aquaculture, 2023)
Infectious diseases are a major burden in aquaculture, and represent a significant yield‐limiting factor in production that is costly to manage as well as a potential vector for zoonoses. Over the past decades, a range of new diseases have emerged, alongside increased levels of antibiotic resistance, thus heightening the need for improved disease management methods supportive of the One Health concept. Simultaneously, recent advances in Next‐Generation Sequencing have increasingly elucidated the role of the microbiome in regulating metabolism, immune function and resilience. Such work has included a plethora of studies on the potential for the management of pathogens through manipulation of the microbiome, as well as related studies of the mechanisms behind host resilience. There is now an increasing robust body of evidence recognizing the importance of a holistic framework in disease aetiology between the host, its environment and colonizing microorganisms, with perturbation increasingly associated with specific dysbiotic states and disease outcomes. Elucidating disease aetiology is a preliminary step towards the development of new prevention methods, with the main goal being early identification of dysbiosis‐associated biomarkers prior to any physical signs of the disease. While acknowledging the challenges associated with using key microbial taxa as biomarkers, we review recent advances in the characterization of dysbiosis and associated microbiome signatures in the context of disease development, with an emphasis on early biomarkers for aquaculture disease prevention. Several promising strategies are suggested, including the use of functional genes or metabolic pathways that are conserved between microbial taxa as a potential proxy for homeostasis.

Production strategies, productivity changes and innovation: An analysis of European turbot aquaculture from 2009 to 2020 - Raquel Fernández‐González; Marcos I. Pérez‐Pérez; João Correia‐da‐Silva (Reviews in Aquaculture, 2023)
After more than four decades of production in the European Union, turbot (Psetta maxima) farming is a mature sector with a moderate growth trend (2.74% in 2020). Although up to seven countries started the production of this species, there are only four producing countries in 2020, with more than 90% of the production concentrated in the Iberian Peninsula. The objective of this paper is to analyse the economic performance of turbot companies in the EU between 2009 and 2020. In this way, biological, environmental, technological, political and social factors will be interrelated with the economic‐financial performance of the sector in order to reach a holistic understanding of this industry. The novelty of this paper lies in the fact that it is the first to analyse the profitability of the 22 turbot companies, aggregated by size and location, in the EU. The results show that the countries that have achieved success in the production of this species, and whose companies are still active today, are those in which several favourable circumstances converge. Among the most important factors are the location of the plants in the natural distribution area of turbot, an adequate institutional climate, and the financial and technological capacity of the companies.

Fish disease and intestinal microbiota: A close and indivisible relationship - Diana Medina‐Félix; Estefanía Garibay‐Valdez; Francisco Vargas‐Albores; Marcel Martínez‐Porchas (Reviews in Aquaculture, 2023)
The gut microbiota is currently one of the most studied ‘organs’ in animals, and fish are no exception. A complex diversity of microbes, including bacteria, archaea, yeast and fungus, constitute the gut microbiota, creating a complex interaction with their host and accomplishing multiple beneficial functions, such as food digestion, nutrient absorption, immune system, endocrine and stress response. The microbiota–pathogen interaction protects the host by mounting colonization resistance, competing for nutrients and space. Changes in the balance of the microbiota community could affect their structure and homeostasis, inducing dysbiosis. In addition, invading pathogens can induce dysbiosis by evading the host's defence barriers, acquiring nutrients from the fish host, using metabolites produced by the microbiota and producing toxins. In this regard, understanding the interactions within the fish gut microbiota is essential to prevent pathogen establishment in the host. Hence, this review describes the close and indivisible relationships and interactions between gut microbiota and pathogens that could lead to dysbiosis and disease.

Towards production of genome‐edited aquaculture species - Eric M. Hallerman; Rex Dunham; Ross D. Houston; Mark Walton; Anna Wargelius; Diane Wray‐Cahen (Reviews in Aquaculture, 2023)

Genomic resources and their applications in aquaculture of Asian seabass ( Lates calcarifer ) - Gen Hua Yue; Le Wang; Zituo Yang; Fei Sun; Yi Xuan Tay; Joey Wong; Shadame Yeo (Reviews in Aquaculture, 2023)
Genomic resources, including nuclear DNA markers, mitochondrial DNA markers, high‐resolution linkage maps, transcriptomes, reference genome sequences and their annotations, are critically important in aquaculture. Their potential applications are plenty, such as enabling the analysis of genetic diversity in population structures, mating and spawning behaviour; genetic traceability; reconstructing pedigrees; mapping quantitative trait loci (QTL) for important phenotypic traits; marker‐assisted selection and genomic selection; and to understand genetic and epigenetic regulation of traits. Asian seabass ( Lates calcarifer ) is becoming a popular aquaculture species. In the past 30 years, many genomic resources have been developed and used to understand the genetic diversity of wild and cultured populations, setting up mating schemes, genetic traceability, mapping QTL and genome‐wide association studies for growth, omega‐3 fatty acid content, resistance to diseases and genetic improvement of important traits in breeding programmes. In this review, we systematically synthesize the status of available genomic resources and their applications in enhancing the genetic improvement and aquaculture production of Asian seabass. We also critically discuss the challenges and future research directions of developing, optimizing and applying genomic resources in Asian seabass aquaculture.

Tributyrin supplementation in fish and crustacean nutrition: A review - Mariana Palma; Leonardo J. Magnoni; Sofia Morais; Ivan Viegas (Reviews in Aquaculture, 2023)
Short‐chain fatty acids, including butyrate and its derived forms, have been used as dietary supplements to reverse or ameliorate the potential negative effects of plant‐derived ingredients in aquaculture diets, and have a multitude of well‐demonstrated physiological and health enhancing effects in mammals and livestock. Tributyrin, a butyric acid derivate, has been assessed as a supplement in the diets of farmed animals, with promising results in several species. In fish and crustaceans, the dietary inclusion of tributyrin is more recent and has been less studied but results suggest that it may be highly advantageous for aquatic animals. This is particularly important for carnivorous species, whose diets need to be optimised towards the reduction of the fishmeal content to enhance the environmental and economical sustainability of the sector. The present work characterises tributyrin and presents the main results of its use as a dietary source of butyric acid in feeds for aquatic species. The main focus is given to aquaculture species and how tributyrin, as a feed supplement, can contribute to optimising plant‐based aquafeeds.

Sustainability outcomes of aquaculture eco‐certification: Challenges and opportunities - Megan E. Rector; Ramon Filgueira; Megan Bailey; Tony R. Walker; Jon Grant (Reviews in Aquaculture, 2023)
Both the aquaculture industry and eco‐certification of aquaculture have grown significantly over the past 20 years, but the extent to which aquaculture eco‐certification is effective in creating positive environmental and societal outcomes is uncertain. Therefore, a scoping review of research on the effectiveness of eco‐certification in improving aquaculture sustainability outcomes, based on systematic search and inclusion criteria, was conducted. Challenges in producing sustainability outcomes through eco‐certification were identified, including (1) choosing which components of sustainability to reflect in eco‐certification criteria, (2) the risk of limiting improvements in sustainability by labelling a product ‘sustainable’, (3) accounting for different spatial scales of aquaculture effects, and (4) designing and applying sustainability criteria that work across different local environments. Potential approaches to these challenges include applying an ecosystem services framework to the identification of issues that could be addressed by eco‐certification criteria, supporting continuous improvement of industry best practices, incorporating criteria related to the far‐field effects of aquaculture, and recognising and accounting for the impact of local conditions on farming and eco‐certification. Although alternate governance approaches may be better suited to ensuring improved sustainability outcomes, potential improvements to eco‐certification criteria and processes are presented as opportunities to match the effectiveness of eco‐certification in creating positive sustainability outcomes to its success in creating a market for eco‐certified farmed seafood. However, some of these improvements may require the addition of criteria or complexity within the eco‐certification process, and their impact on market outcomes, particularly the participation of producers, should be considered.

Applying genetic technologies to combat infectious diseases in aquaculture - Nicholas A. Robinson; Diego Robledo; Lene Sveen; Rose Ruiz Daniels; Aleksei Krasnov; Andrew Coates; Ye Hwa Jin; Luke T. Barrett; Marie Lillehammer; Anne H. Kettunen; Ben L. Phillips; Tim Dempster; et al. (Reviews in Aquaculture, 2023)
Disease and parasitism cause major welfare, environmental and economic concerns for global aquaculture. In this review, we examine the status and potential of technologies that exploit genetic variation in host resistance to tackle this problem. We argue that there is an urgent need to improve understanding of the genetic mechanisms involved, leading to the development of tools that can be applied to boost host resistance and reduce the disease burden. We draw on two pressing global disease problems as case studies—sea lice infestations in salmonids and white spot syndrome in shrimp. We review how the latest genetic technologies can be capitalised upon to determine the mechanisms underlying inter‐ and intra‐species variation in pathogen/parasite resistance, and how the derived knowledge could be applied to boost disease resistance using selective breeding, gene editing and/or with targeted feed treatments and vaccines. Gene editing brings novel opportunities, but also implementation and dissemination challenges, and necessitates new protocols to integrate the technology into aquaculture breeding programmes. There is also an ongoing need to minimise risks of disease agents evolving to overcome genetic improvements to host resistance, and insights from epidemiological and evolutionary models of pathogen infestation in wild and cultured host populations are explored. Ethical issues around the different approaches for achieving genetic resistance are discussed. Application of genetic technologies and approaches has potential to improve fundamental knowledge of mechanisms affecting genetic resistance and provide effective pathways for implementation that could lead to more resistant aquaculture stocks, transforming global aquaculture.

Introduction of non‐native fish for aquaculture in China: A systematic review - Bin Kang; Jean R. S. Vitule; Shan Li; Fangmin Shuai; Liangliang Huang; Xiaoxia Huang; Jinghui Fang; Xiaotao Shi; Yugui Zhu; Dongpo Xu; Yunrong Yan; Fangrui Lou (Reviews in Aquaculture, 2023)
Aquaculture, especially of non‐native species and translocated domestic species, is a greatly encouraged way of relieving the conflicts between food and economic demand and resource depletion. We herein summarized the introduction history of non‐native fish for aquacultural use in China, including 105 species introduced from abroad and 61 species translocated domestically across river basins, which has brought great economic benefits but high ecological risks. Of these, one‐fourth have successfully established wild populations in natural waters and 15% have successfully invaded. We presented specific examples of seven aquaculture species/taxa and three aquarium species/taxa to explain their outcomes. The notable economic benefits, complex species composition and strain selection of tilapias, carps and sturgeons may together facilitate their invasion, and result in fish diversity decline, genetic pollution, and loss of ecosystem service. We specifically reviewed invasion cases in lakes and reservoirs and found that lakes in western China and reservoirs made by major hydroprojects are hotspots for non‐native species, and this has led to the disappearance of endemic species and changes to the original faunal composition. The escaped non‐native fish introduced via aquaculture has changed the original fish biogeography, resulting in the loss of assemblage uniqueness and causing faunal homogeneity. China has achieved significant progress in completing the Aichi Targets by improving the legal system and strengthening conservational actions on controlling non‐native species. Further actions, especially on risk assessment and management of non‐native species are expected for a healthy outlook for the aquaculture industry of China.

Antimicrobial resistance in aquaculture: A global analysis of literature and national action plans - Andrea Caputo; Melba G. Bondad‐Reantaso; Iddya Karunasagar; Bin Hao; Patricia Gaunt; David Verner‐Jeffreys; Sophie Fridman; Alejandro Dorado‐Garcia (Reviews in Aquaculture, 2023)
Since the establishment of a Global Action Plan (GAP) on Antimicrobial Resistance (AMR) (68th World Health Assembly, Geneva, Switzerland, 2015), most members of the World Health Organisation (WHO) have developed and implemented a National Action Plan (NAP) based on a “One Health” approach to AMR. Aquaculture, significant among the food producing sectors, has often been overlooked in AMR governance. We did a systematic review of 95 country NAPs and assessed the inclusion of aquaculture. We also reviewed the scientific literature from 1996 until April 2021 to retrieve data characterising AMR in aquaculture during the last 25 years. In our analysis, 37% of countries did not mention an aquaculture component within their AMR NAP. The South‐East Asia Region had the highest implementation rate of AMR‐aquaculture programmes. Our literature review indicated that most AMR‐aquaculture related studies have taken place in the People's Republic of China, followed by the United States of America and India. Beta‐lactamases, tetracyclines, sulfonamides, macrolides, and fluoroquinolones were the most represented classes of antibiotics, with Vibrio spp. and Aeromonas spp. as the most investigated antimicrobial‐resistant bacteria. This review highlighted the gaps in AMR‐aquaculture governance and the progress made across WHO members. Countries are encouraged to (i) fulfil their commitments by developing and/or fully implementing the AMR NAP, (ii) further engage in the research, monitoring, and surveillance of antimicrobial usage and AMR within the aquaculture sector, and (iii) collaborate at national and international level for a concerted “One Health” approach.

Issue Information (Reviews in Aquaculture, 2023)

From the basics to emerging diagnostic technologies: What is on the horizon for tilapia disease diagnostics? - Ha Thanh Dong; Thawatchai Chaijarasphong; Andrew C. Barnes; Jérôme Delamare‐Deboutteville; Peiyu Alison Lee; Saengchan Senapin; Chadag Vishnumurthy Mohan; Kathy F. J. Tang; Sharon E. McGladdery; Melba G. Bondad‐Reantaso (Reviews in Aquaculture, 2023)
Tilapia is an affordable protein source farmed in over 140 countries with the majority of production in low‐ and middle‐income countries. Intensification of tilapia farming has exacerbated losses caused by emerging and re‐emerging infectious diseases. Disease diagnostics play a crucial role in biosecurity and health management to mitigate disease loss and improve animal welfare in aquaculture. Three continuous levels of diagnostics (I, II and III) for aquatic species have been proposed by Food and Agriculture Organization of the United Nations (FAO) and the Network of Aquaculture Centers in Asia and the Pacific (NACA) to promote the integration of basic and advanced methods to achieve accurate and meaningful interpretation of diagnostic results. However, the recent proliferation of cutting‐edge molecular methods applied in the diagnosis of diseases of aquacultured animals has shifted the focus of researchers and users away from basic approaches and toward molecular diagnostics, despite the fact that many diseases can be rapidly diagnosed using inexpensive, simple microscopic examination and that most emerging diseases in aquaculture were discovered by histopathology. This review, therefore, revisits and highlights the importance of the three levels of diagnostics for diseases of tilapia, particularly the frequently overlooked basic procedures (e.g., case history records, gross pathology, presumptive diagnostic methods and histopathology). The review also covers current and emerging molecular diagnostic technologies for tilapia pathogens including polymerase chain reaction methods (conventional, quantitative, digital), isothermal amplification methods Loop‐mediated Isothermal Amplification (LAMP), recombinase polymerase amplification (RPA), clustered regularly interspaced short palindromic repeats (CRISPR)‐based detection, lateral flow immunoassays, as well as discussing what is on the horizon for tilapia disease diagnostics (next generation sequencing, artificial intelligence, environmental Deoxyribonucleic Acid (DNA) and Ribonucleic Acid (RNA) and point‐of‐care testing) providing a future vision for transferring these technologies to farmers and stakeholders for a sustainable aquatic food system transformation.

The future of intensive tilapia production and the circular bioeconomy without effluents: Biofloc technology, recirculation aquaculture systems, bio‐RAS , partitioned aquaculture systems and integrated multitrophic aquaculture - Sergio Zimmermann; Anders Kiessling; Jiasong Zhang (Reviews in Aquaculture, 2023)
Modern tilapia farming with low use of water aims, as in circular bioeconomy, to reduce inputs and fully reuse waste and effluents, closing flows or links of economic and ecological resources and decentralizing production systems (local production and local consumption). Concerns over diseases, market demand for a clean, sustainable and ecologically correct aquaculture, with greater and more efficient controls, increased predictability and repeatability of activities, are leading to a series of structural changes in the reuse of water and effluents through various closed recirculation systems with the reuse of waste as nutrients. In recent decades, one of the most important innovations and trends of tilapia culture is towards circular bioeconomy, characterized in this review by several recirculation systems, such as biofloc technology (BFT), recirculation aquaculture systems (RASs), bio‐RAS, partitioned aquaculture systems (PASs with split ponds, SPs; and in pond recirculation system, IPRS) and integrated multitrophic aquaculture (IMTA). The future of tilapia culture meshes with urban agriculture and waste fermentation, where low‐demand water recirculation systems will be the protagonists in the disruption of industries in five main sectors (materials, energy, information, transport and food/health), that still today focus on extraction, into a more sustainable local model.

From Africa to the world—The journey of Nile tilapia - Abdel‐Fattah M. El‐Sayed; Kevin Fitzsimmons (Reviews in Aquaculture, 2023)
Despite the fact that Nile tilapia ( Oreochromis niloticus ) (Linnaeus, 1758) are African freshwater fish, they have been introduced into many countries inside and outside Africa. The journey of Nile tilapia started during the second half of the 20th Century, especially in Southeast Asia and the Americas, mainly for aquaculture and fisheries enhancement. Most of these introductions became well established in aquaculture. As a result, aquaculture of Nile tilapia has been steadily expanding in many countries. These fish play an important role in the livelihoods of local societies on different continents. This review summarizes the current knowledge on global Nile tilapia introductions and sheds light on their social and economic contributions to the countries into which they have been introduced, as well as their share in the global fish market. The ecological impacts of tilapia introductions have also been addressed. The success stories of the major Nile tilapia producers were highlighted so that the lessons learned from their experiences could be transferred to other countries.

Bacterial diseases of tilapia, their zoonotic potential and risk of antimicrobial resistance - Olga L. M. Haenen; Ha Thanh Dong; Truong Dinh Hoai; Margaret Crumlish; Iddya Karunasagar; Timothy Barkham; Swaine L. Chen; Ruth Zadoks; Andreas Kiermeier; Bing Wang; Esther Garrido Gamarro; Masami Takeuchi; et al. (Reviews in Aquaculture, 2023)
Tilapia culture is an important source of income and nutrition to many rural families. Since 2000, the production of tilapia increased and reached domestic and global markets. Major farmed species is Nile tilapia ( Oreochromis niloticus ), in earthen ponds and cage cultures. Intensification contributed to global tilapia disease outbreaks, with bacterial infections causing mortalities and morbidities, threatening sustainable production. At tilapia farms, high nutrient concentrations, water temperature and fish densities enhance bacterial growth including virulent bacterial clones and potential zoonotic bacteria. Global warming favours this. This review respectively provides a comprehensive overview of the most common and emerging bacterial pathogens, diseases, clinical presentations and diagnostics of tilapia, including bacteria and diseases with zoonotic potential. First, common bacterial disease outbreaks, including streptococcosis, motile Aeromonas septicaemia, francisellosis, columnaris disease and vibriosis are described. Then, information on emerging bacterial infections of concern for tilapia, like edwardsiellosis through Edwardsiella ictaluri and E . tarda , as well as Aeromonas schubertii is provided. Reports of infectious bacterial tilapia disease outbreaks from other bacteria, including Lactococcus garvieae , Aerococcus viridans , Pseudomonas spp., Mycobacterium marinum and Chlamydia spp., and others are reviewed. Furthermore, bacteria with zoonotic potential, like Streptococcus agalactiae ST283, S . iniae , Aeromonas sp., E . tarda , Vibrio vulnificus pathovar (pv) piscis and M . marinum are included in the review, to provide the most current overview of the disease risks affecting production and post‐harvest stages. Additionally, the status and risks of antimicrobial resistance in bacteria from tilapia and other cultured fish through imprudent use of antibiotics, and its future at a global level are provided.

A global review of problematic and pathogenic parasites of farmed tilapia - Andrew P. Shinn; Annemarie Avenant‐Oldewage; Melba G. Bondad‐Reantaso; Armando J. Cruz‐Laufer; Adriana García‐Vásquez; Jesús S. Hernández‐Orts; Roman Kuchta; Matt Longshaw; Matthijs Metselaar; Antoine Pariselle; Gerardo Pérez‐Ponce de León; Pravata Kumar Pradhan; et al. (Reviews in Aquaculture, 2023)
Over the past 80 years, tilapia have been translocated globally for aquaculture; active production is recorded in >124 countries. Of 7 million tonnes of tilapia produced in aquaculture, 79% is from 79 countries outside the natural range of tilapia. Capture fisheries account for a further 723,627 tonnes of tilapia, and >47% of this is landed from established invasive populations outside Africa. Tilapias host a rich fauna of parasites, many of which have been translocated with their hosts. This review summarises >2500 host–parasite records from 73+ countries and >820 recorded tilapia translocations (provided in the supplementary materials). This work focuses on the notable pathogens that threaten the health of cultured populations of tilapia, providing a description of their pathology and includes species that also have substantial impacts on wild tilapia populations, where relevant. For each major parasite taxonomic group, we highlight which parasites have been translocated or have been acquired from the new environments into which tilapia have been introduced, together with remarks on standard treatment approaches and research on them and their management and control. Regarding the theme ‘Tilapia health: quo vadis ?’, Africa has enormous potential for aquaculture growth, but substantial knowledge gaps about tilapia parasites in many African states remain, which creates associated production and biosecurity risks. For each parasitic group, therefore, the risks of parasite translocation to new regions as tilapia aquaculture industries expand are highlighted.

Improving tilapia biosecurity through a value chain approach - Brett MacKinnon; Partho Pratim Debnath; Melba G. Bondad‐Reantaso; Sophie Fridman; Hao Bin; Omid Nekouei (Reviews in Aquaculture, 2023)
Tilapia aquaculture is a major source of animal protein, with global production reaching over 6 million tonnes in 2020. The rapid growth of the tilapia sector has led to a number of emerging disease threats and subsequent production losses. Risk analysis can provide a targeted approach for improving biosecurity in the tilapia sector. The aim of this work was to describe the tilapia value chain and review the important infectious agents of tilapia that may affect the different points along the value chain; such points include input and service suppliers, producers (i.e., hatcheries, nurseries and grow‐out farms), and processors, traders and marketers. We then describe how risk analysis can be used to identify critical controls points along the value chain and describe potential risk mitigation measures that may be implemented at those points. The control of diseases of tilapia requires a multi‐faceted approach, with risk‐based control measures chosen based on their feasibility, effectiveness and sustainability. The Progressive Management Pathway for Improving Aquaculture Biosecurity, as a risk‐based, collaborative and progressive management approach combined with the systematic preventive principles of Hazard Analysis Critical Control Point, offers a strategic and practical way of improving biosecurity in the tilapia value chain.

Tilapia health: quo vadis ? - Devin M. Bartley; J. Richard Arthur; Kevin Fitzsimmons; Michael J. Phillips; Melba G. Bondad‐Reantaso (Reviews in Aquaculture, 2023)

Strategies to enhance tilapia immunity to improve their health in aquaculture - Bei Wang; Kim D. Thompson; Eakapol Wangkahart; Jidapa Yamkasem; Melba G. Bondad‐Reantaso; Puntanat Tattiyapong; Jichan Jian; Win Surachetpong (Reviews in Aquaculture, 2023)
Various emerging and re‐emerging diseases, such as streptococcosis, tilapia lake virus disease and infectious spleen and kidney necrosis virus disease, have had a significant economic impact on the tilapia industry over the last decade. These diseases have resulted in high levels of morbidity and mortality, production losses and trade restrictions. In the absence of effective husbandry management, disease prevention strategies and appropriate biosecurity measures, infectious diseases will continue to challenge the sustainability of global tilapia aquaculture. Strategies used to reduce the impact of disease include feeding probiotic and prebiotic supplements to enhance tilapia health and to modulate the fish's gut microbiota to improve gut health. Herbal medicines and immunostimulants are also used to enhance immunity to disease, while vaccines are available, or are under development, for a number of economically important pathogens affecting tilapia culture. This review provides an overview of the benefits of enhancing the immune response of tilapia to improve their health, and in turn reduce the levels of pathogens within tilapia farming systems.

How value addition by utilization of tilapia processing by‐products can improve human nutrition and livelihood - Omar Peñarubia; Jogeir Toppe; Molly Ahern; Ansen Ward; Michael Griffin (Reviews in Aquaculture, 2023)
Aquatic foods, particularly fish, are recognized as a unique source of essential fatty acids, micronutrients and protein many diets lack, especially in poor and vulnerable communities. Tilapia ( Oreochromis sp.) fillets typically represent 30%–33% of the fish, leaving around 70% of the fish unused for human consumption. These nutrient‐rich by‐products can be converted into food and other products with medical, pharmaceutical and packaging applications. Heads and backbones of processed tilapias, and undersized tilapia can be used in the development or fortification of food products such as fish cakes, sausages and bread. Tilapia skin can be processed into leather for clothing and leather artefacts. Gelatin from fish skin can be developed into edible films and coating while collagen from fish scales and bones has good application in the cosmetic and pharmaceutical fields. The viscera can be converted into biodiesel or silage and hydrolysates, which are good sources of peptides and enzymes. To ensure 100% utilization, any remaining parts of the fish not used for food, can be transformed into products for animal consumption or for fertilizer. Thus, the conversion of by‐products from tilapia processing into value‐added products can contribute to improve human nutrition and better livelihood opportunities. However, adopting new technologies in value addition will require additional operational costs for acquiring new equipment and skills, a proven market demand for the products and an enabling policy environment.

Spanish Abstracts (Reviews in Aquaculture, 2023)

Tilapia introduction in China: Economic boom in aquaculture versus ecological threats to ecosystems - Wen Xiong; Chuanbo Guo; Rodolphe E. Gozlan; Jiashou Liu (Reviews in Aquaculture, 2023)
The introduction and use of non‐native species in aquaculture have played a central role in the development of this economic sector worldwide. Tilapia is one of the most widely introduced species in the world, and China has become the largest producer and consumer of tilapia. While non‐native tilapia in China support provisioning ecosystem services of substantial economic value, the invasion also poses potential threats to native fish diversity, ecosystems and ultimately the sustainable fisheries development. However, knowledge regarding the invading pathway, aquaculture development, economic benefits and the ecological impacts of such important non‐native species is still limited, especially in China. Based on thorough literature review as well as field surveys, this paper has comprehensively presented the introduction of tilapia species across a range of aquatic habitats and its role in the aquaculture industry growth, emphasising the economic benefits in China. In addition, we also synthesised the potential negative ecological impacts caused by tilapia invasion with global evidences, which will provide excellent lessons and management recommendations for China and other countries worldwide. Future trends tend to indicate an increase in the number and frequency of tilapia's introduction in China, with an increasing likelihood of environmental impacts. However, it is apparent that the aquaculture of non‐native tilapias is a highly profitable activity in China which makes the introductions inevitable, therefore, alternative management strategies and implications are further discussed to seek to achieve more sustainable and ecosystem‐friendly aquaculture, reduce the risks and negative impacts on ecosystems while still maintaining the economic benefits.

Recent progress of male sexual differentiation and development in the oriental river prawn ( Macrobrachium nipponense ): A review - Shubo Jin; Wenyi Zhang; Yiwei Xiong; Hongtuo Fu (Reviews in Aquaculture, 2023)
Many researchers have focused on male sexual differentiation and development of the Macrobrachium nipponense in recent years. In this review, we highlight the status of knowledge about male sexual differentiation and development in this species by summarizing the chromosome analyses, major regulatory factors, identification of male reproduction‐related genes and gene functional analyses. Fifty‐two chromosomes have been identified in the testis of M. nipponense , which led to the identification of sex‐related chromosomes in this prawn. Studies have shown that hormones secreted by the eyestalk, androgenic gland, and testis as well as 17‐estradiol and environmental factors regulate the process of male sexual development in M. nipponense . The sex differentiation and development sensitive period was identified as post‐larva 10 (PL10) to PL22; therefore, this time span is critical in the identification of male reproduction‐related genes from M. nipponense . In this study, 80 male sex‐related homologous genes were identified based on functional analysis in other species, and another 45 genes were considered to be strong male reproduction‐related candidates based on their expression changes through performing multi‐omics profiling analyses. Quantitative polymerase chain reaction analysis revealed 25 genes that were involved in the process of male sexual development in M. nipponense , and RNA interference showed that knockdown of the expression levels of SDHB , PDHE1 , NFkBa , HSDL1 and ferritin delayed testis development. Use of Crispr‐Cas9 technology and analysis of noncoding RNA should be further investigated, which will be effective in establishing an artificial technique to regulate the process of male sexual development in M. nipponense .

Arabic abstracts (Reviews in Aquaculture, 2023)

Mixotrophic cultivation of microalgae for carotenoid production - Fakhra Liaqat; Mahammed Ilyas Khazi; Ali Bahadar; Lu He; Ayesha Aslam; Rabia Liaquat; Spiros N. Agathos; Jian Li (Reviews in Aquaculture, 2023)
The intrinsic ability of microalgae to accumulate high amounts of carotenoids has made them the preferred aquatic organisms of biotechnological exploration for carotenoid production. To continuously innovate and modify microalgal bioprocesses, aquaculture scientists have been working hard for the past decades in a forward‐looking way, and mixotrophic cultivation of microalgae is deemed as a promising strategy to decrease production cost. This review is intended to summarise the recent research advancement of carotenoids production from mixotrophically cultivated microalgae, starting from the structure, biosynthesis, physiological roles and applications of carotenoids and followed by the production processes both currently established and under development. Most importantly, the microalgal physiology of mixotrophic cultivation is reviewed in depth both in general and specifically for the most studied species, and the prospects of commercially viable mixotrophic microalgal processes for carotenoid production along with the insight of future research are of course discussed. Finally, we conclude that mixotrophy might be a promising strategy for large‐scale cultivation of microalgae to produce carotenoids although some technical obstacles need to be overcome.

Cultivation of fish ciliate parasites: Progress and prospects - Ming Li; Giana Bastos Gomes; Weishan Zhao; Guangran Hu; Ke Huang; Tomoyoshi Yoshinaga; Theodore G. Clark; Wenxiang Li; Hong Zou; Shangong Wu; Guitang Wang (Reviews in Aquaculture, 2023)
Ciliates are considered the most harmful parasites of fish, causing mass mortalities and thus substantial economic losses to the aquaculture and ornamental fish industries. To better elucidate their pathogenic mechanisms and facilitate the development of effective prevention and control strategies, it is essential to apply novel technologies to ensure the continuous and sufficient supply of parasite specimens. This review discusses the latest research progress in the artificial culture of six important parasitic ciliates affecting both freshwater and marine fish globally: Ichthyophthirius multifiliis , Cryptocaryon irritans , Chilodonella ( C. hexasticha , C. piscicola and C. uncinata ), Balantidium ctenopharyngodoni , Scuticociliatida gen. spp., and Tetrahymena spp. Methods for in vitro and in vivo culture as well as cryopreservation/preservation (depending on the specific species) of these organisms are described herein. Challenges and future applications of parasite culture are also discussed.

More and diverse contributions from aquaculture - Pin Nie (Reviews in Aquaculture, 2023)

Portuguese‐Brazilian abstracts (Reviews in Aquaculture, 2023)

The changing role and definitions of aquaculture for environmental purposes - Darien D. Mizuta; Halley E. Froehlich; Jono R. Wilson (Reviews in Aquaculture, 2023)
Aquaculture is the fastest growing form of food production across the globe. The expansion of the industry has brought about a diversity of approaches to mitigate social and ecological impacts associated with aquaculture production systems. At the same time, there is a growing interest in utilizing aquaculture for conservation purposes including species recovery, habitat restoration and offsetting the impacts of wild capture on vulnerable harvested species. The diversification of the aquaculture sector and the overlapping use of terminology to describe alternative aquaculture approaches can create challenges for policy makers, managers and industry practitioners. Clear distinction between alternative aquaculture approaches and intent may improve regulatory, permitting, monitoring and consumer awareness outcomes. Here, we examine the use of four primary aquaculture approaches in the scientific literature: ‘commercial aquaculture’, ‘conservation aquaculture’, ‘restorative aquaculture’ and ‘regenerative aquaculture’ to elucidate the similarities and differences and improve understanding of the approaches. We propose definitions for the terms based on empirical analysis of related words used in scientific texts and fitness into a particular initiative. In addition, we discuss the use of those terms within the context of benefits to ‘people and nature’, namely activities that include economic, social and environmental outcomes and the variability therein. Clear definition of terms and related activities in a burgeoning field can minimize semantic confusion while improving opportunities to craft robust policy guidelines and improve stakeholder understanding and practice of aquaculture activities.

Embracing nanotechnology for selenium application in aquafeeds - Hala Saber Khalil; Sahya Maulu; Marc Verdegem; Mohsen Abdel‐Tawwab (Reviews in Aquaculture, 2023)
Selenium (Se) is an important micronutrient that has been used in aquafeeds for the normal growth, welfare and health of aquatic animals. Through nanotechnology, Se can be converted into nanoparticles that are more bioavailable, utilized and absorbed by aquatic animals. However, this is still a new and emerging area of research in aquafeeds. This paper aims to review the effect of Se and Se nanoparticles (Se‐NPs) application in aquafeeds on aquatic animals. Specifically, different compounds of Se, requirement levels by different species, effects on animal growth, physiology, antioxidant capacity and immune response have been highlighted. The review shows that the application of Se in aquafeeds could improve the growth performance, physiology, antioxidant enzymes, immunity and disease resistance in aquatic animals. However, the effectiveness could be highly influenced by the source of Se, aquaculture species and administration quantity. Through nanotechnology, the utilization and absorption of Se could be improved while reducing its toxicity. Therefore, Se‐NPs present an efficient way to utilize nutrients in aquafeeds. Important gaps, however, exist in the current knowledge, particularly with regard to the response of shrimps and crustaceans to dietary supplementation of Se and Se‐NPs as most of the existing studies have focused on fish species. Also, some species of economic importance and life stages have not been investigated, which hinders the embracement of nanotechnology in aquafeeds production.

Replacement of fish meal with fermented plant proteins in the aquafeed industry: A systematic review and meta‐analysis - Muziri Mugwanya; Mahmoud A. O. Dawood; Fahad Kimera; Hani Sewilam (Reviews in Aquaculture, 2023)
In the aquaculture feed industry, fishmeal is widely used as a source of animal protein due to its high palatability, excellent amino acid profile and increased digestibility. However, the incorporation of fishmeal in aquaculture diets increases the costs of production due to the declining wild fish stocks hence an urgent need to search for sustainable and cheaper alternative protein sources. The use of fermented plant proteins as substitutes for fishmeal in aquaculture diets has recently gained attention due to their improved nutritional quality, easy availability and low costs. Therefore, a systematic review and meta‐analysis were conducted to quantify the effects of fermented plant proteins as substitutes for fishmeal on the growth performance, feed utilisation, survival, antioxidant, metabolic and digestive enzyme activity of several aquaculture species. Results of the meta‐analysis indicated that replacement of fishmeal with fermented plant proteins in aquaculture diets enhanced the growth performance, feed utilisation, antioxidant and digestive enzyme activities of several aquaculture species regardless of experimental duration and source of fermented plant protein. Likewise, metabolic enzyme activity (i.e., Alanine aminotransferase and Aspartate aminotransferase) was reduced in experimental dietary treatment groups relative to the fishmeal control groups. To elucidate the influence of moderators on the observed effect sizes, a mixed‐effects model was conducted and the results indicated that fishmeal substitution levels and aquaculture species influenced the observed effect sizes in both antioxidant and digestive enzyme activity. No significant differences were noted in survival between the experimental dietary treatment groups and fishmeal control diets among all aquaculture species. However, carnivorous marine species exhibited lower values for specific growth rate and protein efficiency ratio in experimental dietary treatment groups compared to the fishmeal control diets. Likewise, freshwater species exhibited poor FCR values in experimental dietary treatment groups relative to the fishmeal control diets. Overall, the replacement of fishmeal with fermented plant proteins in aquaculture diets is a safe and viable solution for increased and sustainable aquaculture production.

Creatine: A valuable supplement in aquafeeds? - Sven Wuertz; Stefan Reiser (Reviews in Aquaculture, 2023)
Creatine is an amino acid derivate commonly found in vertebrate muscle tissue. Creatine facilitates the recycling of adenosine triphosphate and thus contributes to the energy supply of the muscles as well as the brain. Creatine is used as a supplement for several reasons and its effects in humans, particularly in sports medicine, have been studied excessively. Also, creatine supplementation has been studied for its functions and benefits in terrestrial farm animals. Up to date, little is known about the use of creatine as a supplement in fish nutrition. Yet, due to its many physiological functions, creatine may serve as a valuable supplement in aquafeeds of farmed aquaculture species. Indeed, creatine plays a pivotal role in the fish's muscle and may help to enhance performance of fish reared in aquaculture systems. With regard to swimming exercise, creatine may even amplify its metabolic effects. Upon supplementation, creatine stimulates muscle growth increasing body mass and it has the potential to improve feed utilisation particularly of plant‐based diets. Also, creatine plays a part in osmoregulation when fish adapt to changes in salinity. Furthermore, it may improve product quality upon slaughter. Here, we compile what is known about the many functions of creatine as well as its physiological effects in fish in comparison to mammals. We also highlight its potential beneficial effects as a supplement in aquaculture and infer why creatine can help increase the sustainability of fish feeds.

A review on the pathogenic bacterium Nocardia seriolae : aetiology, pathogenesis, diagnosis and vaccine development - Yansheng Liu; Guoquan Chen; Liqun Xia; Yishan Lu (Reviews in Aquaculture, 2023)
Nocardia seriolae , a gram‐positive branching filamentous bacterium, is the causative agent of fish nocardiosis. It mainly infects fish through gills, anus, lateral line or surface injury, resulting in a large number of white nodules in visceral organs and skin ulcerations. N. seriolae can infect about 42 species of fish and severely harm the aquaculture industry in many regions, particularly in Asia. Aiming to have a more comprehensive understanding about N. seriolae , the literature of N. seriolae before January 2022 was collected by searching nine databases and the current knowledge of the host diversity, drug resistance, genotype and phenotype, virulence factor, molecular detection and vaccine development of N. seriolae was summarized in this review. The future studies of N. seriolae are also prospected in order to help the research on the pathogenic mechanism and control of N. seriolae infection .

Progress towards reestablishing Latin America as a major pearl producing region: A review - Pedro E. Saucedo; Douglas McLaurin; César Lodeiros; Luis Freites; Luis León; Jorge I. Cáceres‐Puig; Marcos C. P. Albuquerque; Paul C. Southgate; Héctor Acosta‐Salmon (Reviews in Aquaculture, 2023)
Globally, pearl culture is a profitable sector generating significant export incomes for producer countries, as well as livelihood opportunities for local communities. Latin America has a long history as a pearl producer from extensive fisheries that date back to the 15th century. The presence of pearl oyster beds on the Pacific and Caribbean coasts of many Latin American countries was a major incentive for colonisation of the region and subsequent social and economic development of areas in the Gulf of California and the Caribbean. This review presents the historic background of the pearl fishery in this region since the arrival of the Spanish in the 16th century, describes the current status of pearl culture in Latin America, and outlines future opportunities for sector development. Information on the current status of pearl culture in Latin American countries is divided between two major categories: commercial and pilot‐scale. Commercial pearl production currently occurs only in Mexico and production updates are provided for bead‐nucleated, half pearls (mabé) and non‐nucleated (keshi) pearls from the two pearl farms operating in the Gulf of California. The second category comprises countries whose pearling activities were relevant in the past (Venezuela, Panama) and others that are emerging, but still maintain pilot‐scale production of mabé pearls using Pteria sterna (Ecuador, Peru), Pinctada mazatlanica (Panama) and Pteria hirundo (Brazil). Finally, this review discusses future prospects for pearl culture in Latin America, analysing technology gaps and challenges to be addressed if the cultured pearl sector is to achieve its full potential in this region.

Issue Information (Reviews in Aquaculture, 2023)

Antimicrobial resistance in fish pathogens and alternative risk mitigation strategies - Vijaya Kumar Deekshit; Biswajit Maiti; Ballamoole Krishna Kumar; Akshatha Kotian; Gillaine Pinto; Melba G. Bondad‐Reantaso; Iddya Karunasagar; Indrani Karunasagar (Reviews in Aquaculture, 2023)
The discovery of antimicrobial agents, particularly antibiotics, is one of the most important milestones in the history of therapeutics. Since their discovery, antibiotics have been widely used in human medicine, veterinary, agriculture and aquaculture sectors. Many of the antibiotics used in human and veterinary medicine are also being used in the aquaculture sector either for therapy or as prophylactic agents. However, there is increasing awareness and concern for the indiscriminate use of antibiotics and the consequent emergence of antimicrobial resistance in the aquaculture settings. An aquatic environment, especially if it is eutrophic, provides a suitable niche for many bacterial pathogens to survive and multiply. Although there are limited reports of large‐scale outbreaks in the aquaculture sector directly caused by antibiotic resistant fish pathogens, the presence of transferable plasmids, transposons and integrons in fish pathogens such as Aeromonas spp . , Edwardsiella spp. and Vibrio spp . is a cause of concern. Thus, the need to study the resistance determinants found in these transmissible elements to different classes of antibiotics carried by fish pathogens and, their dissemination is highly relevant.

Chinese abstracts (Reviews in Aquaculture, 2023)

Reproductive sterility in aquaculture: A review of induction methods and an emerging approach with application to Pacific Northwest finfish species - Lan Xu; Mingli Zhao; Jun Hyung Ryu; Edward S. Hayman; William T. Fairgrieve; Yonathan Zohar; J. Adam Luckenbach; Ten‐Tsao Wong (Reviews in Aquaculture, 2023)
Aquaculture is the fastest‐growing food‐production sector and is striving to become a long‐term sustainable approach to meet the rising global demand for seafood. During the expansion and advancement of aquaculture, minimizing ecological impacts should occur concomitantly with maximizing production. Farmed fish, often genetically distinct from their natural conspecifics, may pose significant risks of genetic contamination and ecological imbalance to wild populations if they escape from aquaculture confinement. Growing reproductively sterile fish is the most effective way to genetically contain farmed fish. Atlantic salmon ( Salmo salar ) escape events in the ‘Pacific Northwest’ region of the United States and Canada have raised alarms over potential ecological impacts and led to legislation in Washington State phasing out the culture of non‐native finfish species. Farming sterile native species such as coho salmon ( Oncorhynchus kisutch ) and sablefish ( Anoplopoma fimbria ) in the Pacific Northwest would ease public concerns and promote environmentally and economically sustainable aquaculture. Sterile fish also can mitigate the challenge of precocious maturation, a prominent issue associated with culture of salmonids and many other species, to improve somatic growth, flesh quality and fish health and welfare. Here, we review methods having potential applications for producing sterile fish and introduce our novel immersion‐based technology that temporarily silences the dead end ( dnd ) gene using Morpholino oligonucleotides to produce sterile coho salmon and sablefish for the first time. The successful induction of sterility in these two iconic Pacific Northwest species without introducing genetic modifications would promote the use of this immersion‐based sterilization technology for more aquaculture finfish worldwide.

Long non‐coding RNA , a supreme post‐transcriptional immune regulator of bacterial or virus‐driven immune evolution in teleost - B. Haridevamuthu; Ajay Guru; Manikandan Velayutham; P. Snega Priya; Aziz Arshad; Jesu Arockiaraj (Reviews in Aquaculture, 2023)
The global aquaculture boom, fuelled by a reduction in wild population and detection of novel viruses, has created a demanding market, hence, there is a pressing need to investigate the immune system of fish, further. As the most diverse community of vertebrates and a central contributor to the progressing global aquaculture market, teleost continues to draw vast scientific interest. Recent breakthroughs in multi‐omics technologies have provided a platform to understand the role of long non‐coding RNA (lncRNA) in the host immune system during infection. Emerging evidence shows that teleost lncRNA might have a regulatory role in immune responses, mostly through lncRNA–microRNA (miRNA) sponging. Teleost lncRNA shares a functionally active short sequence complement to target the miRNA which is conserved among the several fish species. Recent report suggests that rhabdovirus exploits a lncRNA in teleost and, to dodge the host immune mechanism and negatively regulate the immune system. This observation reveals the essentiality of lncRNA in pathogen‐driven immunity in teleost. Reports available on the function of teleost lncRNA are still in early stages and experimental verifications are a limiting factor. Unravelling the lncRNA‐mediated immune regulation in fishes could be used against the invading pathogens to strengthen the aquaculture production. This review elaborates on the experimentally identified and functionally characterized lncRNA and its regulatory role in the teleost immune response during infection and pathogen‐driven host immune evolution, which could eventually lead to achieving high standards in aquaculture productivity.

Non‐antibiotic approaches to combat motile Aeromonas infections in aquaculture: Current state of knowledge and future perspectives - Le Thanh Dien; Thao Phuong Huynh Ngo; Thao V. Nguyen; Pattanapon Kayansamruaj; Krishna R. Salin; Chadag Vishnumurthy Mohan; Channarong Rodkhum; Ha Thanh Dong (Reviews in Aquaculture, 2023)
Inland aquaculture contributed by three major fish groups, including carps, tilapias, and catfish plays a vital role in global food security and nutrition, particularly in low and middle‐income countries. However, the sustainable development of this sector is hampered by disease epidemics, especially those caused by bacteria such as Aeromonas species. At least eight pathogenic motile Aeromonas species ( A. hydrophila , A. veronii , A. jandaei , A. caviae , A. sobria , A. bestiarum , A. dhakensis and A. schubertii ) have been reported in aquaculture with some causing up to 100% mortality during disease outbreaks. Simultaneously, emerging multidrug‐resistant Aeromonas due to a long‐inappropriate use of antibiotics is alarming and highlights a global public health concern and negative socioeconomic impacts. Here, we provide a comprehensive overview of motile Aeromonas infections, antibiotic use and antimicrobial resistance of Aeromonas species . This contribution also highlights the non‐antibiotic approaches (the solutions for preventing or treating of bacterial diseases without resorting to antibiotic use) to control motile Aeromonas infections. In addition to the current state of knowledge and limitations of each prophylaxis/therapy, perspectives for future research are discussed critically, including oral/immersion multivalent vaccines, microencapsulated synbiotics, exogenous metabolites, and novel lytic bacteriophage cocktails. Some emerging applicable nanotechnology themes such as nanovaccines, nanobioactive compounds, and nanobubbles are also included in this review. In summary, combating motile Aeromonas infections in aquaculture, including multidrug‐resistant aeromonads, as well as other bacterial diseases, is a lengthy battle that requires a strategic combination of multiple non‐antibiotic approaches coherent with the One Health philosophy.

Cover Image - Ming Li; Giana Bastos Gomes; Weishan Zhao; Guangran Hu; Ke Huang; Tomoyoshi Yoshinaga; Theodore G. Clark; Wenxiang Li; Hong Zou; Shangong Wu; Guitang Wang (Reviews in Aquaculture, 2023)

Use of antimicrobials in Chilean Salmon farming: Facts, myths and perspectives - Ruben Avendaño‐Herrera; Marcos Mancilla; Claudio D. Miranda (Reviews in Aquaculture, 2023)
Chile is the second largest producer of salmon (only behind Norway), and high amounts of antimicrobials are used during the marine stage, mainly florfenicol. Intensive antimicrobials use is a relevant concern, prompting the urgent need for use reduction and advancements towards more restricted, efficient application. This review describes the historic and current use of antimicrobials in Chilean salmonid farming. Further covered is the experimental evidence reported to date, thus providing a clearer understanding for the pathogenic nature of Piscirickettsia salmonis —the most important bacterial pathogen and the main target of antimicrobials used in the Chilean industry. This review also assesses research exploring the impacts of antimicrobial treatment on the environment, as well as investigations on the antibiotic susceptibility of salmonid pathogens. This review of the scientific literature contributes to a more unbiased appraisal of the current situation in Chile. Unfortunately, various previous reports dealing with/on the antimicrobial use in the Chilean salmon farming industry have been arrived to insufficiently supported conclusions, thus the present review aims to clarify outdated or poorly substantiated information and assumptions in existing literature. The consequences of antimicrobials in fish farming are covered by this review, which is particularly relevant considering potential impacts on aquatic environments. Focus is given to the selection and spread of drug‐resistant bacteria and associated resistance‐encoding genes. Finally, herein are provided several recommendations from a One Health perspective for decreasing amounts of used antimicrobials, effectively controlling primary bacterial fish pathogens, developing proper prevention strategies and reducing the dissemination of antimicrobial resistance.

Enhancing the nutritional values of farmed fish production systems - Devin M. Bartley; Malcolm C. M. Beveridge; Michael J. Phillips; Albert G. J. Tacon; Marc Verdegem (Reviews in Aquaculture, 2023)

Genomic selection and its research progress in aquaculture breeding - Hailiang Song; Tian Dong; Xiaoyu Yan; Wei Wang; Zhaohui Tian; Ai Sun; Ying Dong; Hua Zhu; Hongxia Hu (Reviews in Aquaculture, 2023)
Since its introduction in 2001, genomic selection (GS) has progressed rapidly. As a research and application hot topic, GS has led to a revolution in the field of animal and plant breeding. Thanks to its ability to overcome the shortcomings of traditional breeding methods, GS has garnered increasing attention. Both theoretical and practical breeding studies have revealed the higher accuracy of GS than that of traditional breeding, which can accelerate genetic gain. In recent years, many GS studies have been conducted on aquaculture species, which have shown that GS produces higher prediction accuracy than traditional pedigree‐based method. The present study reviews the principles and processes, preconditions, advantages, analytical methods and factors influencing GS as well as the progress of research in aquaculture into these aspects. Furthermore, future directions of GS in aquaculture are also discussed, which should expand its application to more aquaculture species.

The role of ferroptosis in fish inflammation - Feng Gao; Xiaowei Shi; Chao Pei; Xianliang Zhao; Lei Zhu; Jie Zhang; Li Li; Chen Li; Xianghui Kong (Reviews in Aquaculture, 2023)
Ferroptosis, as one of cell death modalities, is driven by iron‐dependent phospholipid peroxidation and regulated by various cellular metabolic pathways, including iron, amino acid and lipid metabolism, as well as disease‐related signalling pathways. Cell survival or death is a critical issue in the inflammatory response. On the one hand, ferroptosis is more immunogenic than apoptosis, and ruptured ferroptotic cells release damage‐associated molecular patterns (DAMPs), which can trigger an inflammatory response. On the other hand, various pathogenic bacteria may cause peroxidation of polyunsaturated fatty acids (PUFAs) on the cell membrane, leading to ferroptosis. In fish, the key genes and signalling pathways related to ferroptosis are conserved, but there are still differences among fish species. In recent years, frequent occurrences of fish diseases have posed a considerable challenge to the large‐scale aquaculture. The specific precursors for ferroptotic cell death were iron‐dependent oxidative stress and lipid peroxidation, which always occur in fish inflammation. This review summarizes recent studies on ferroptosis in fish inflammation, that is, iron‐dependent programmed cell death, to address ferroptosis, inflammation and correlations between them in fish. This review may contribute to a better understanding of the underlying mechanisms of ferroptosis and inflammation in fish and provides suggestions for sustainable development and large‐scale aquaculture farming.

Environmental risk assessment of non‐native salmonid escapes from net pens in the Chilean Patagonia - Doris Soto; Ivan Arismendi; J. Andres Olivos; Cristian B. Canales‐Aguirre; Jorge Leon‐Muñoz; Edwin J. Niklitschek; Maritza Sepúlveda; Felipe Paredes; Daniel Gomez‐Uchida; Yuri Soria‐Galvarro (Reviews in Aquaculture, 2023)
Here, we review extensive information to estimate environmental risks from escaped non‐native salmonids based on the assessments of hazard , sensitivity and exposure of discrete water bodies in Chile. In 2020, the country harvested about 1 million tons salmonids from net pens located along 1500 km of highly biodiverse coastline. We base our analysis on existing scientific information and authors' expert opinions including an assessment of knowledge gaps and uncertainties. Risks of environmental impacts differed by salmon species, being lowest for Atlantic salmon due to its estimated lower survival, lower ability to feed after escaping and lower reproductive capacity in the wild compared to coho salmon and rainbow trout. Overall risks due to escapes of any of the species were highest in areas of both high farming intensity and low capacity of mitigating escapes (by wild predators and fishers) such as Aysén District. At same time, risk was higher in the most farmed areas that also presented suitable habitats to support reproduction and juvenile salmonid rearing. However, the risk estimation certainty differed among species being lowest for Atlantic salmon due to insufficient monitoring of their fate in the wild. Monitoring the fate and impacts of escaped salmonids, specially in higher risk areas is recommended to improve risk projections and to prevent and mitigate further impacts. Since Atlantic and coho salmon are not yet successful invaders in Chile, research attention is urgently needed to assess the environmental consequences of escapes of these species. The present approach can be applied to any aquaculture system given the availability of information on farmed species and receiving ecosystems.

The Pacific white shrimp, the most cultivated shrimp species, is it Litopenaeus or Penaeus vannamei ? - Arnaldo Figueredo; Carlos Lira; Jonathan Vera‐Caripe; Marcos De Donato; César Lodeiros (Reviews in Aquaculture, 2023)

Ingestion of anthropogenic debris by marine fishes around New Zealand - Peter L. Horn (New Zealand Journal of Marine and Freshwater Research, 2022)
A summary is presented of the anthropogenic debris recorded up to 2020 in stomachs of marine fishes from New Zealand waters. This material (mainly plastics) was found in the stomachs of 28 species, with 24 of these species identified in two studies alone. Most of the New Zealand records were not identified in recently published global assessments of plastic ingestion by fish; the likely reasons for this are discussed. Consumption of anthropogenic debris by fish in New Zealand waters is probably a widespread phenomenon, particularly for inshore demersal species with an algal dietary component and for offshore pelagic species that prey on gelatinous biota. Based on currently available data, this behaviour may occur relatively less frequently in deeper water demersal habitats, although no studies investigating the ingestion of microplastic particles by fish in this section of the New Zealand marine environment have yet been completed. The likelihood of identifying plastics in fish diets is strongly dependent on the analytical method used.

Response of tidal creek networks and tidal connectivity to coastal squeeze of saltmarshes in the southern Bohai Bay - Xuezhong Fan; Huamei Huang; Qinglong Zhang; Na Sun; Yangang Wang (New Zealand Journal of Marine and Freshwater Research, 2022)
Coastal squeeze of saltmarshes (CSS) has substantially eliminated valuable intertidal habitats and worsened local tidal hydrological environment by disintegrating tidal creek networks and losing tidal connectivity (TC). In this study, we explored the process response of creek network structure and TC to CSS dynamics, taking the southern Bohai Bay of China as a case study area. With the Landsat series data and ArcGIS spatial analysis, the morphological and structural evolution of tidal creek systems were quantified by four parameters: creek order, creek length, creek branch point, and network catchment area. Also, the TC was assessed and visualised based on a geostatistical connectivity method. It was found that low‐order small creeks were more sensitive and vulnerable to CSS and the creek network would face disintegration when about 50% of the saltmarsh squeeze degree occurred, which has been observed as a crucial threshold. In the seaward direction, the CSS process has led to the continuous replacement of high TC areas by low TC areas, greatly altering the original natural TC pattern. Revealing the relationship between CSS and creek network structure and TC will allow a further understanding of the degradation of intertidal ecosystems, and will promote their ecological and hydrological restoration.

Gonadal development in a landlocked population of pejerrey fish Odontesthes argentinensis during spawning season in relation to sex steroids and water temperature - Pamela Sabrina del Fresno; Darío César Colautti; Gustavo Emilio Berasain; Leandro Andrés Miranda (New Zealand Journal of Marine and Freshwater Research, 2022)
The relationship between water temperature and gonadal maturation of a landlocked ecophenotype of marine pejerrey ( Odontesthes argentinensis ) in La Salada de Pedro Luro lake was analysed during three spawning seasons. Mainly vitellogenic females were found in August (winter), some ovulating in October (mid‐spring) and with atretic oocytes in December (end of spring). In accordance with this, gonadosomatic index (GSI) and estradiol plasma levels showed maximum values in October (7.6 ± 0.7%; 1631.7 ± 256.1 pg/mL) and minimum values in December (1.2 ± 0.3%; 230,33 ± 8,74 pg/mL). Spermiating males were found during the whole spawning season and only arrested in December. The highest GSI values were recorded in October (4.6 ± 0.2%) and for testosterone (T) in August (1113.2 ± 503.8 pg/mL). Meanwhile, in December the minimum GSI and T plasma values (1.3 ± 0.6%, 323.8 ± 5.3 pg/mL) were observed. According to the Fourier fitted models, temperature explains more than 70% of the observed variation in GSI in both sexes. Moreover, the total GSI variation range was positively related to the total temperature range variation experienced during the reproductive seasons demonstrating the influence of this environmental variable on maturation intensity and dynamics.

Stream bank erosion as a source of sediment within New Zealand catchments - Andrew O. Hughes; Manawa K. Huirama; Philip N. Owens; Ellen L. Petticrew (New Zealand Journal of Marine and Freshwater Research, 2022)
Stream bank erosion has been anecdotally identified as an important source of sediment in New Zealand catchments, however, there have been few attempts to quantify its contribution. Here we use a radionuclide‐based sediment tracing approach to determine the relative contribution of stream bank‐ and hillslope‐derived sediment within three catchments in the upper North Island of New Zealand. Both lithogenic (radium‐226 and radium‐228) and fallout radionuclides (caesium‐137 and excess lead‐210) were used to differentiate sediment derived from stream bank and hillslope sources. The relative contribution of stream banks and hillslopes to fluvially transported suspended sediment were predicted using a mixing model approach. Our results indicate that both fallout and lithogenic radionuclides provide good source differentiation. We demonstrate that stream bank erosion can contribute very high proportions of sediment within New Zealand catchments. We used independent assessments of bank erosion from each of the study catchments to support the sediment source fingerprinting results. Further work is required to determine the spatial and temporal variability of the contribution of sediment from stream banks. Information on the importance of different sediment sources is needed to target limited catchment rehabilitation resources where they will have the most impact.

Suspended sediment and faecal contamination in a stormflow plume from the Hutt River in Wellington Harbour, New Zealand - Mark P. Gall; Rob Davies‐Colley; Juliet Milne; Rebecca Stott (New Zealand Journal of Marine and Freshwater Research, 2022)
Muddy, faecally‐contaminated river flood plumes in coastal waters are a hazard to contact recreation and bivalve shellfish consumption but are difficult to study, being episodic and transient. We used a new underway flow‐through sampler in a small, fast boat, to map a flood plume within Wellington Harbour, while simultaneously sampling water in the Hutt River inflow. Faecal contamination (indexed by E.coli) correlated with flow, salinity, coloured dissolved organic matter, total suspended solids (TSS) and water clarity (light beam attenuation and visual clarity). The freshwater content of the plume agreed well with time‐integrated river discharge. Despite the relatively short time‐scale ( E. coli (suggesting some die‐off) occurred in the plume compared to river loads. E. coli relative to TSS varied up to two orders of magnitude over a year of river flood sampling. A rapid survey of plumes combined with long‐term river observations is expected to augment monitoring and inform the extension of remote sensing and modelling efforts to faecal contamination of New Zealand coastal waters.

Use of a multi‐metric macroalgal index to document severe eutrophication in a New Zealand estuary - Leigh M. Stevens; Barrie M. Forrest; Bruce D. Dudley; David R. Plew; John R. Zeldis; Ude Shankar; Arman Haddadchi; Keryn L. Roberts (New Zealand Journal of Marine and Freshwater Research, 2022)
Environmental indicators that reliably describe estuary trophic response to nutrient loading are required for the effective management of New Zealand estuaries. A common estuary eutrophication response is frequent, extensive and persistent opportunistic macroalgae blooms. This study explores the utility of the Opportunistic Macroalgal Blooming Tool (OMBT) in the New River Estuary (∼4600 ha), a shallow intertidal‐dominated system within a pastoral farming catchment in Southland, New Zealand. Total nitrogen (TN) loads increased from 3206 T y −1 in 2000 to 5143 T y −1 in 2020. Concomitantly, areas of opportunistic macroalgae, measured using the OMBT, expanded across the available intertidal habitat (AIH) from 34.9 ha or 1.4% of the AIH to 1383 ha or 47.6% of the AIH, and the average wet weight biomass increased from 19.3 g m −2 to a peak of 1326 g m −2 in 2019. We hypothesise that opportunistic macroalgae expanded rapidly in direct response to temporal increases in TN load, with increases disproportionately contributed by expansion and intensification of dairy farming in the catchment. This study confirmed that the OMBT predictably responded to changes in TN concentration and may therefore be useful in defining estuary‐specific TN concentration thresholds to inform likely load reductions required to achieve improved environmental outcomes.