Implementing ecological intensification in fish farming: definition and principles from contrasting experiences - Joël Aubin; Myriam Callier; Hélène Rey‐Valette; Syndhia Mathé; Aurélie Wilfart; Marc Legendre; Jacques Slembrouck; Domenico Caruso; Eduardo Chia; Gérard Masson; Jean Paul Blancheton; Ediwarman; et al. (Reviews in Aquaculture, 2019)
Ecological intensification is a new concept in agriculture that addresses the double challenge of maintaining a level of production sufficient to support needs of human populations and respecting the environment in order to conserve the natural world and human quality of life. This article adapts this concept to fish farming using agroecological principles and the ecosystem services framework. The method was developed from the study of published literature and applications at four study sites chosen for their differences in production intensity: polyculture ponds in France, integrated pig and pond polyculture in Brazil, the culture of striped catfish in Indonesia and a recirculating salmon aquaculture system in France. The study of stakeholders’ perceptions of ecosystem services combined with environmental assessment through Life Cycle Assessment and Emergy accounting allowed development of an assessment tool that was used as a basis for co‐building evolution scenarios. From this experience, ecological intensification of aquaculture was defined as the use of ecological processes and functions to increase productivity, strengthen ecosystem services and decrease disservices. It is based on aquaecosystem and biodiversity management and the use of local and traditional knowledge. Expected consequences for farming systems consist of greater autonomy, efficiency and better integration into their surrounding territories. Ecological intensification requires territorial governance and helps improve it from a sustainable development perspective.

Behaviour in the toolbox to outsmart parasites and improve fish welfare in aquaculture - Samantha Bui; Frode Oppedal; Michael Sievers; Tim Dempster (Reviews in Aquaculture, 2019)
Host behaviour can prevent infection and moderate the fitness of parasites. Antiparasite behaviours are prevalent in many host–parasite systems and occur over fine or broad scales. With global growth in aquaculture production and the associated proliferation of parasites in farming systems, the behaviour of the fish being farmed has seldom been investigated in relation to parasites. Epidemics and outbreaks of parasites are prevalent in most aquaculture systems, and behaviour could be harnessed in concert with current methods to prevent and control parasites and pathogens. However, this requires a systematic understanding of the behaviours of hosts, their capacity for resistance and their interaction with the environment and the parasite. Herein, we present evidence for how behaviour could be used in aquaculture, and discuss the possibility for behaviour to be used in aquaculture as (i) an indicator of welfare status, (ii) a tool in prevention or control and (iii) to maintain or improve welfare. We apply this framework to a case study of a highly problematic parasite, the salmon louse ( Lepeophtheirus salmonis ), on farmed Atlantic salmon ( Salmo salar ). We present the current state of the system, and the drawbacks of current control or prevention methods. We synergise current knowledge on host behaviours and show how behaviour could be incorporated into current and new approaches for prevention and control. Through this first evaluation of the possibilities behaviour presents in disease management, we aim to facilitate a shift in the current disease control paradigm from reactive‐based post‐infection control to pre‐infection prevention approaches.

Enabling mātauranga‐informed management of the Kaipara Harbour, Aotearoa New Zealand - Maria Hepi; Jeffrey Foote; Leane Makey; Monique Badham; Alyssce Te Huna (New Zealand Journal of Marine and Freshwater Research, 2018)
The Integrated Kaipara Harbour Management Group (IKHMG) promotes the integrated management, inter‐agency coordination and kaitiakitanga of the Kaipara Harbour and its catchment. Led by the hapū (subtribe) Te Uri o Hau, the group is a collective of stakeholders and community. In 2013, the Institute of Environmental Science and Research (ESR) and Te Uri o Hau examined the IKHMG to understand what enables and hinders mātauranga‐informed management of the Kaipara Harbour. A review of literature relating to mātauranga and environmental resource management found a myriad of issues in integrating indigenous knowledge with science, or with indigenous knowledge holders working with scientists and/or resource managers. Our cross‐cultural collaborative research examined to what extent the IKHMG overcame these issues and incorporated mātauranga into planning and decision‐making. We make the case that the challenge facing cross‐cultural integrated catchment programmes should not be so much ‘how to integrate indigenous knowledge into resource management’ but ‘how to integrate indigenous knowledge holders into planning and decision‐making’ to enable indigenous knowledge holders to articulate management in their own terms as an expression of self‐determination.

Māori oral traditions record and convey indigenous knowledge of marine and freshwater resources - Hēmi Whaanga; Priscilla Wehi; Murray Cox; Tom Roa; Ian Kusabs (New Zealand Journal of Marine and Freshwater Research, 2018)
Whakataukī are part of a strongly developed Māori oral tradition that conveys critical information about aspects of life, society and tribal memory, including ecological knowledge. Such codified knowledge depends on language use and structure as a key mechanism for cultural transmission. Additionally, many meanings may not be apparent without knowing the historical, cultural and linguistic context from which the whakataukī originated. We examined a primary dataset of c. 3500 versions of whakataukī , drawn from collections published after European arrival c. 200 years ago, to determine how marine and freshwater principles, practices and knowledge bases have developed in response to changing environmental and societal contexts in Aotearoa. We present information on marine and freshwater resources contained in whakataukī to shed light on the connections between humans and their environment that transcend prosaic uses and enlighten deeper social and behavioural engagement with the surrounding environment. Understanding past engagement can help shape future marine and freshwater relationships in Aotearoa.

Fishing for the cultural value of kahawai ( Arripis trutta ) at the Mōtū River, New Zealand - Kimberley H. Maxwell; Te Whānau‐a‐Hikarukutai Ngāti Horomoana; Richard Arnold; Matthew R. Dunn (New Zealand Journal of Marine and Freshwater Research, 2018)
Fisheries management has an important role in sustaining fisheries‐dependent cultures. We describe the cultural values of the Mōtū kahawai ( Arripis trutta ) fishery for Te Whānau‐a‐Hikarukutai/Ngāti Horomoana (TWAH/NH). Using a kaupapa‐Māori approach and culturally appropriate social science methods, cultural values of the Mōtū kahawai fishery were shared. The Identified Cultural Influence (ICI) index determined if kahawai is a cultural keystone species (CKS) for TWAH/NH. TWAH/NH have developed distinct, centuries‐old wisdom, protocols and practices through their interactions with the kahawai. The fishery contributes to their identity and the ICI results suggest that kahawai is TWAH/NH’s CKS. Indigenous knowledge and management systems can provide sustainable management practices improving how cultural values connected to fisheries are enhanced. We recommend culturally appropriate information sharing and analysis methods used here, for efficiently describing the cultural significance of fisheries. Increasing the CKS fisheries recognised will emphasise the need for fisheries managers to sustain cultural values.

Mātauranga Māori driving innovation in the New Zealand scampi fishery - Shaun Ogilvie; Robert Major; Alaric McCarthy; Glenice Paine; Richard Paine; Geoff Connor; Steve Connor; David Taylor; Andrew Jeffs; Kevin Heasman; Chris Batstone; Benita Chambers; et al. (New Zealand Journal of Marine and Freshwater Research, 2018)
Motivation to improve commercial fishing technology is changing from ‘how can we catch more fish’ to ‘how can we reduce the impact of fishing on the environment’. To implement new fisheries technologies and innovations, it is important to have sources of innovative ideas for improvement, and processes to allow the uptake and transition from old to new technologies. One fishery that is undergoing a technology transition is the New Zealand scampi ( Metanephrops challengeri ) fishery. Here we report on a research programme aimed at improving the cultural and environmental performance of scampi fishing practices, initiated by the Māori‐owned Waikawa Fishing Company, and underpinned by Mātauranga Māori and values inherent in kaitiakitanga. This paper provides a case study for how Mātauranga Māori and western science can engage in a fisheries technology transition through a transdisciplinary research programme.

Using Māori knowledge to assist understandings and management of shellfish populations in Ōhiwa harbour, Aotearoa New Zealand - Kura Paul‐Burke; Joseph Burke; Charlie Bluett; Tim Senior (New Zealand Journal of Marine and Freshwater Research, 2018)
This article discusses a marine research project which prioritised mātauranga Māori (Māori knowledge systems) to generate common management approaches and responses for the taonga (culturally important) species; Kūtai, Perna canaliculus , Green Lipped Mussel populations in Ōhiwa harbour, Aotearoa New Zealand. Findings from the trans‐disciplinary marine research project were used to develop a mussel management action plan (MMAP) which was endorsed and accepted in its entirety by the high‐level Māori tribal and Governmental partners of the Ōhiwa Harbour Implementation Forum (OHIF). This article provides an overview of research which used localised Māori knowledge systems to provide the foundations for improving, enhancing and safeguarding traditional mussel populations in the harbour. Further, this article critically positioned mātauranga Māori as an important and meaningful strategy for empowering Māori collaboration and voices in the wise use, care and practical management of marine taonga species for present and future generations.

Evaluation of a traditional Māori harvesting method for sampling kōura (freshwater crayfish, Paranephrops planifrons ) and toi toi (bully, Gobiomorphus spp.) populations in two New Zealand streams - Ian A. Kusabs; Brendan J. Hicks; John M. Quinn; William L. Perry; Hēmi Whaanga (New Zealand Journal of Marine and Freshwater Research, 2018)
Representative sampling of crayfish in streams is often impractical, especially in non‐wadable habitats, or in areas with soft substrates. Whakaweku are artificial habitats made from bracken fern ( Pteridium esculentum ) that can be used successfully in a range of habitats. We compared whakaweku, minnow traps, fyke nets and electrofishing for sampling freshwater crayfish (kōura; Paranephrops planifrons ) and bullies (toi toi; Gobiomorphus spp .) in two streams with differing stream characteristics and fish assemblages. Whakaweku captured a full‐size range of kōura of both sexes, including small kōura (OCL 7–12 mm) that were not caught by minnow traps or fyke nets. Colonisation by kōura reached 90% of maximum after 2 weeks and CPUE was constant from 2 to 9 weeks. After 9 weeks, CPUE decreased due to decay of the fern fronds. Whakaweku are an effective sampling tool that are inexpensive, simple to set, and do not require expensive equipment or specialised training.

Tuākana/Teina Water Warriors Project: A collaborative learning model integrating mātauranga Māori and science - Phyllis Callaghan; Ripeka Paraone; Maiki Murray; Ngaikiha Tahau; Saffron Edgarton; Ewan Bates; Ewarini Ataria; Harero Heremaia; Nukutai Rupene; Emily Wilson; Lochlan Hanham; Daniel Soal; et al. (New Zealand Journal of Marine and Freshwater Research, 2018)
Our waterways, particularly in urban environments, are subject to increasing pressures from human activity. Similarly, urbanisation has irreversibly changed the Māori cultural experience of their natural world including freshwater ecosystems. The Water Warriors is a collaborative project between Te Pā o Rākaihautū and Hagley Community College that was established to look after the waterways and re‐connect rangatahi (youth) with these environments within urban Ōtautahi (Christchurch). Fundamental to this project was the opportunity to integrate science with mātauranga Māori as equally valid knowledge systems. In doing this, our pononga (students) will not have to wait until they are adults to enjoy and experience science through a Māori world view and through this work simultaneously bring to life a cultural narrative of science. This paper describes the Water Warriors initiative along with an active student voice reflecting on their experiences.

Whakamanahia Te mātauranga o te Māori: empowering Māori knowledge to support Aotearoa’s aquatic biological heritage - James Ataria; Melanie Mark‐Shadbolt; Aroha Te Pareake Mead; Kevin Prime; Jim Doherty; James Waiwai; Tohe Ashby; Simon Lambert; Gary Owen Garner (New Zealand Journal of Marine and Freshwater Research, 2018)
As Aotearoa New Zealand grapples with developing solutions to complex issues surrounding its unique freshwater and marine biological heritage, there is a growing recognition that mātauranga Māori can be ‘unlocked’ and used with great effect alongside western science. Examples where appropriate consideration and development of robust methodologies for the application of mātauranga Māori coexisting alongside western science are increasing. Unfortunately, despite the benefits that can be derived from this collaboration, the quality of engagement is not always satisfactory often due to poor interpersonal relationships and misidentification of the knowledge holders. By providing an appropriately historical context, this article is able to consider the critical issues now facing mātauranga and the Māori knowledge holders today, and fundamental requirements that will empower application of this knowledge within bio‐heritage management. We consider how the development of a methodology between mātauranga Māori holders and potential end‐users might contribute to improved outcomes for Aotearoa’s biological heritage.

East Otago Taiāpure: sharing the underlying philosophies 26 years on - Anne‐Marie Jackson; Christopher D. Hepburn; Brendan Flack (New Zealand Journal of Marine and Freshwater Research, 2018)
Taiāpure (local fishery) are Customary fisheries Protection Areas (CPAs) designed to make better provision for rangatiratanga (Māori chieftainship) under Article II of te Tiriti o Waitangi. The East Otago Taiāpure was applied for in 1992 and finally gazetted in 1999. It has been twenty‐six years since the East Otago Taiāpure was applied for and the East Otago Taiāpure Management Committee has incorporated mātauranga‐ā‐hapū (sub‐tribal knowledge) as well as local knowledge to inform decision making to advocate for better management of local fisheries and ecosystems for the benefit of all people and the generations to come. We provide a narrative from over a quarter of a century of management of the East Otago Taiāpure to provide a useful reference for communities wishing to explore the taiāpure concept to realise rangatiratanga for their uri (descendants) to come.

Relationships between Maori values and streamflow: tools for incorporating cultural values into freshwater management decisions - Shannan K. Crow; Gail T. Tipa; Doug J. Booker; Kyle D. Nelson (New Zealand Journal of Marine and Freshwater Research, 2018)
This study aimed to develop quantitative relationships for Maori cultural values supported by streamflow. We examined the results of a Cultural Flow Preference Study (CFPS) for five streams in Canterbury, New Zealand, and used mixed effects models to quantify how observed streamflow supported scores for Overall Health (OH). Relationships between streamflow and OH differed between sites and assessors within each site. Ignoring differences between sites and assessors, there was a positive relationship that explained 5% of the variation between streamflow and OH. After accounting for differences between sites and assessors, there was a positive relationship that explained 53% and 62% of the variation respectively. Flow attributes sustaining cultural values are based on the characteristics of the site and relationships change between rivers. Our study provides a transferable framework for developing cultural health–flow relationships that will enable Maori to be involved from the outset of any environmental flow assessment.

Indigenous and local peoples’ values of estuarine shellfisheries: moving towards holistic‐based catchment management - Ani Alana Kainamu‐Murchie; Islay D. Marsden; Rawiri T. M. Tau; Sally Gaw; John Pirker (New Zealand Journal of Marine and Freshwater Research, 2018)
Estuaries support a wide range of human activities and values, but are one of the most anthropogenically impacted ecosystems in the world. Ki uta ki tai is a holistic view of waterways that is embodied within Ngāi Tahu environmental management, which acknowledges the connectivity between environmental systems and people with the environment. While this philosophy is referred to within current policies, management does not effectively account for or reflect this philosophy. This research evaluated indigenous and local socio‐cultural values provided by estuarine shellfisheries across Waitaha/Canterbury and found Ngāi Tahu place‐based interaction was impacted by management and anthropogenic inputs. Participants’ estuarine stressors aligned with global stressors. Experienced harvesters/fishers adapted their practices to these stressors, while less experienced harvesters/fishers visited high food‐risk sites. Effective management requires identifying the risks to socio‐cultural values towards accountability of activities, to meet the ethic of ki uta ki tai.

Mātauranga Māori: shaping marine and freshwater futures - Joanne Clapcott; Jamie Ataria; Chris Hepburn; Dan Hikuroa; Anne‐Marie Jackson; Rauru Kirikiri; Erica Williams (New Zealand Journal of Marine and Freshwater Research, 2018)

Classifying the mauri of wai in the Matahuru Awa in North Waikato - Aareka Hopkins (New Zealand Journal of Marine and Freshwater Research, 2018)
Moohiotanga Tuku Iho, contemporary maatauranga and western science were used to classify the mauri (life force) of wai (water) in Matahuru Awa (river) in North Waikato. Moohiotanga Tuku Iho is tuupuna (ancestral) knowledge passed down through generations and together with local classifications were the guiding principles for using attributes of Taaonga Tuku Iho (treasures inherited) as parameters to classify the mauri of wai. Taaonga Tuku Iho in the taiao (environment) whakapapa (genealogy) to Papatu‐aa‐nuku (earth mother) and Ranginui‐aa‐tea (sky father), and subordinate atua (gods) ensured the continued existence of taaonga would maintain the mauri of wai in awa. Models in the literature were used to explore the advantages re‐establishing ngaahere (forest) where they have been removed for manu (birds) to nest and breed for example, advantages that would not only enhance the mauri of the wai in Matahuru Awa, it would restore the mana (respect) of the hapuu (sub tribe).

Murihiku Cultural Water Classification System: enduring partnerships between people, disciplines and knowledge systems - Jane C. Kitson; Ailsa M. Cain; Muriel N. Te Huikau Johnstone; Rewi Anglem; Jane Davis; Moana Grey; Aimee Kaio; Stevie‐Rae Blair; Dean Whaanga (New Zealand Journal of Marine and Freshwater Research, 2018)
The Murihiku Cultural Water Classification System is founded on partnerships between people, disciplines and knowledge systems. This freshwater management framework is being developed at the scale of the Te Ara Koroka Pounamu Trail. Numerous barriers prevented Ngāi Tahu ki Murihiku use of the trail from around the 1880s; however, this cultural landscape and the values, beliefs and practices it supports (past, present and future) are still central to the identity of Murihiku whānau. To help reconstruct and revitalise mātauranga Māori around Te Ara Koroka, historical literature sources were used, alongside cultural value mapping, interviews and contemporary information sources. This paper explores cultural heritage methods to show how indigenous knowledge can be meaningfully and respectfully protected in research programmes. We propose that access requirements and protection mechanisms used by museums, libraries and archives could inform improved processes to better protect mātauranga Māori within the New Zealand science and innovation system.

Severed at the head: towards revitalising the mauri of Te Awa o te Atua - Dan Hikuroa; Julia Clark; Anthony Olsen; Erin Camp (New Zealand Journal of Marine and Freshwater Research, 2018)
Te Awa o te Atua, known today as the Tarawera River, lies in the Bay of Plenty, North Island, New Zealand. Despite its immense importance to iwi, it has been subject to intense anthropogenic pressures and modification over the past century. Ngāti Rangitihi, one iwi kaitiaki of the river, wanted to understand how the mauri of Te Awa o te Atua has been impacted, with the ultimate aim of revitalising the mauri. Drawing from mātauranga Māori and science the analysis undertaken provides insights for a recovery plan that Ngāti Rangitihi can champion. Critically this approach has identified solutions that neither body of knowledge could have reached in isolation. Using the Mauri Model, the mauri of the Te Awa o te Atua was determined to be significantly depleted, with the re‐routing of the Tarawera River severing the head of the river and stranding the lagoon having had the most negative impact. Glossary of Māori words: Iwi: kinship group; Kāinga: home, village, settlement; Kaitiaki: guardian; Kaitiakitanga: guardianship; Kaupapa: values and principles; Kōrero: accounts; Mahinga kai: food‐gathering practice; Mamae: deeply felt intergenerational hurt; Mana whenua: territorial authority; Mātauranga Māori: māori knowledge, culture, values and world view; Mauri: life force (see also section in text); Pūrākau: codified maori narrative; Taonga: treasure (noun), to be treasured (verb); Te Awa o te Atua River of the Gods; Tikanga: cultural practices; Tino rangatiratanga: chiefly autonomy; Tuna: eel; Urupā: burial ground; Waka: canoe; Wānanga: discuss and deliberate; Whakaoranga te iwi: revitalise health for the people; Whakapapa: drawing identity from; Wheke: octopus

Issue Information (Reviews in Aquaculture, 2018)

Chinese Abstracts (Reviews in Aquaculture, 2018)

A simplistic approach to detect health anomalies at a regional level using shrimp production data - Ana Muniesa; Julio Cabanillas‐Ramos; Imanol Ruiz‐Zarzuela; Francisco J. Magallón‐Barajas; Ignacio de Blas (Reviews in Aquaculture, 2018)
The global production and yield of shrimp ponds depend on multiple factors, and an unexpected variation in production parameters could be an indicator of pathological events such as white spot disease (WSD) outbreaks in a syndromic surveillance system. Using the production data from 7139 production cycles at farm level collected at two Mexican states (Sonora and Sinaloa) from 2004 to 2011, an ecological survey (also called correlational study) has been carried out summarizing data for year and oceanic basin. The production results had been analysed looking for significant association ( P

Intelligent feeding control methods in aquaculture with an emphasis on fish: a review - Chao Zhou; Daming Xu; Kai Lin; Chuanheng Sun; Xinting Yang (Reviews in Aquaculture, 2018)
In aquaculture, feeding is the primary factor determining efficiency and cost, so it is important to know when to stop feeding to maximize efficiency. Until now, fish feeding has been mostly based on artificial discrimination, which is usually time‐consuming and laborious. In recent years, intelligent feeding control according to changes in behaviour and growth status has gained increasing attention. This approach involves many methods as well as monitoring and feedback equipment and can automatically determine the feeding demands of fish. This review summarizes the development of intelligent feeding control methods, such as mathematical models, acoustic methods and computer vision, in aquaculture over the past three decades. All methods have unique application scenarios and models for the culture to which they are most suitable, and the advantages and disadvantages of each method in the laboratory as well as in pond, cage and recirculating aquaculture systems are analysed. Studies show that improvements in sensor accuracy and hardware and software processing speed have promoted the development of new technologies and methods, providing effective or potential support for intelligent feeding control. However, its accuracy and intelligent are still need to be improved to meet the needs of actual feeding scenarios. Through close collaborations between engineers and fish behaviourists, the feeding machine and system will be more elaborate and precise on the basis of the above methods, and the level of intelligence will be further improved.

Beneficial roles of feed additives as immunostimulants in aquaculture: a review - Mahmoud A.O. Dawood; Shunsuke Koshio; Maria Ángeles Esteban (Reviews in Aquaculture, 2018)
The use of antibiotics in the aquafeeds to mitigate infectious diseases or to boost growth performance is commonly practiced. Recently, the prophylactic use of antibiotics and chemotherapies have been criticized which eventually led to their ban in aquaculture by law on many countries. In view of the current restrictions on antibiotic use, there is a critical need to evaluate other possible alternatives. One potential substitute for antibiotics in aquafeeds is the use of functional feed additives. The present review is a comprehensive and an updated compilation of the available works on different feed additives, their examples, modes of action and useful applications for improving aquafeeds. It highlights several functional feed additives including probiotics, prebiotics, synbiotics, immunostimulants, organic acids, nucleotides and medicinal herbs. Apart from boosting aquafeeds and safeguarding general health of aquatic animals, some of these substances have been found to possess beneficial immunostimulant and anti‐stress relieving properties. Furthermore, the use of these natural substances increases the consumer confidence of farmed fish. Due care has been taken to cover the on‐going trends and recent advances with a perspective vision and their holistic usages and beneficial applications in aquatic animals’ systems. The current study also shed light regarding the management and production aspects of aquatic animals which will enlighten farmers and producers for better economic growth.

Nutrition in ornamental aquaculture: the raise of anthropocentrism in aquaculture? - Benedetto Sicuro (Reviews in Aquaculture, 2018)
Ornamental aquaculture nutrition is profoundly different from conventional aquaculture nutrition from several points of views as the prices, finality and diversity. This paper tries to answer to some simple questions: do modern ornamental fish feeds reflect more physiological fish needs or aquarist expectations? What are the driving forces behind the modern aquarium nutrition? On the light of the considerations made in this paper, it emerges that popularity of ornamental aquaculture is largely influenced by a progressive humanization of ornamental fish. Obesity and longevity transfer is the most evident nutritional effect of pet proximity to humans and this special kind of ‘contagion’ is observable in ornamental fish too. Assuming that aquarium fish have been humanized, ornamental fish industry has taken profit from this. A drastic change happens to fish feeds after crossing the human doorstep. This is probably ignored by humans, but not by ornamental aquafeed companies that sometimes induce erroneous customer expectations to improve their profits. Feeding an ornamental fish in our modern society represents a symbolic action more referred to humans than to fish physiological needs; therefore, human psychology affects the ornamental fish feeds quality much more than the fish physiology. This is the main and illogical conclusion of this paper. This paper tries to enlighten some unexpected relationship between us (humans) and this modern category of domesticated animals: aquarium fish and to give some possible future perspectives.

Improving feed efficiency in fish using selective breeding: a review - Hugues de Verdal; Hans Komen; Edwige Quillet; Béatrice Chatain; François Allal; John A.H. Benzie; Marc Vandeputte (Reviews in Aquaculture, 2018)
Improving feed efficiency ( FE ) is key to reducing production costs in aquaculture and to achieving sustainability for the aquaculture industry. Feed costs account for 30–70% of total production costs in aquaculture; much work has been done on nutritional and husbandry approaches to improve FE but only a limited amount of research has been devoted to using genetics, despite its potential. This paper reviews past work to improve FE in fish using selective breeding and assess future directions. Direct selection on FE traits requires methods to measure individual feed consumption and estimate FE efficiently and accurately. This is particularly difficult to do in fish because of the environment in which they live. Many of the published studies on FE were found to be inaccurate because of methodological problems. The relatively low heritability estimates of FE traits in fish published to date are probably partly as a result of inaccurate measurements of feed intake. Improving ways to measure the individual feed intake with high accuracy will be critical to the successful application of genetics to improving FE . Indirect selection criteria that could be used to improve FE (including growth after starvation/refeeding, body composition, neuropeptides or hormone levels) are discussed. Promising approaches to measuring feed intake accurately that may enable these studies to be undertaken are identified. More work using these will be needed prior to assessing the practicality of the introduction of direct or indirect traits for FE in fish genetic improvement programmes.

A critical analysis of the international legal framework regulating the microbiological classification of bivalve shellfish production areas - Robson Ventura de Souza; Carlos Campos; Luis Hamilton Pospissil Garbossa; Luiz Fernando de Novaes Vianna; Argeu Vanz; Guilherme Sabino Rupp; Walter Seiffert (Reviews in Aquaculture, 2018)
This study presents a review of the microbiological standards and associated monitoring practices for classification of commercial shellfish production areas in force in Brazil, European Union and United States of America. The classification systems are not immediately comparable principally because some regulations are based on the monitoring of water and others of shellfish flesh. To create a common baseline to compare these regulations, regression models were developed based on monitoring data and used to correlate levels of faecal indicator bacteria in water and in shellfish. The classification system used in the European Union was found to provide the highest level of shellfish safety for classification categories that do not require post‐harvest treatments prior to marketing, while the United States system provides higher level of shellfish safety for classification categories that require these treatments. The Brazilian legislation prescribes depuration as the post‐harvest treatment for shellfish with much higher levels of coliforms than the United States and European Union systems. Evidence was found that the microbiological limits for sea water set out in the Brazilian Resolution 357 – CONAMA are more stringent than the regulations used in the European Union and United States. The results also suggest that the Brazilian Shellfish Sanitation Programme and the European Union legislation are the least stringent concerning maximum faecal contamination tolerated. This assessment provides information on margins of safety for shellfish products traded internationally.

Prebiotics as functional ingredients: focus on Mediterranean fish aquaculture - Inês Guerreiro; Aires Oliva‐Teles; Paula Enes (Reviews in Aquaculture, 2018)
The increased demand for food fish, together with the banning of antibiotics for fish growth promotion and the greater public awareness for healthy fish production, led to an increased interest in the potential of functional feeds as health promoters. Prebiotics are functional ingredients that are used in fish, being reported to be associated with improvements in growth, feed efficiency, gut microbiota, digestive enzyme activities, gut morphology, immune status, disease resistance, intermediary metabolism, and stress responses. Those benefits may be related with the increase in gut beneficial bacteria, bacteria end‐products of prebiotic fermentation, or the interaction between prebiotics and pattern recognition receptors. Due to the reported prebiotic‐related positive effects in fish, a large amount of studies have been published in the last years, mainly focusing on prebiotics’ benefits to fish. Thus, the present review focuses on prebiotics’ potential as functional ingredients, focusing on their mechanisms of action. In addition, this review summarizes prebiotic effects in Mediterranean aquaculture fish, whose production has greatly increased in the last years. Finally, topics that deserve to be further explored, such as prebiotic effects related with fish age and size, and timing and duration of administration are suggested.

Systems and techniques used in the culture of soft‐shell swimming crabs - Camila Prestes dos Santos Tavares; Ubiratã Assis Teixeira Silva; Leandro Angelo Pereira; Antonio Ostrensky (Reviews in Aquaculture, 2018)
The academic interest in the production of soft‐shell swimming crabs has increased in direct proportion to the increasing demand worldwide for this gastronomic delicacy. The techniques of obtaining this product are essentially based on the maintenance of swimming crabs at premoult stage in open, semi‐closed or closed farming systems, until the moment of moulting. These different types of systems reflect the biological e environmental control method evolution. To achieve industrial scale production of soft swimming crabs, the option of using closed systems has increased in recent years. This type of system offers several advantages, such as greater control over environmental variables, greater ease of installation, higher storage densities, greater ease of monitoring ecdysis occurrence and, especially, the possibility of incorporating several forms of automation. In this review, the main production systems currently used, as well as the main techniques for obtaining the animals, their management under controlled conditions, harvesting and slaughter, are presented and discussed, focusing on future perspectives for the world production of soft‐shell swimming crabs.

Epigenetics in aquaculture – the last frontier - Luana Granada; Marco F.L. Lemos; Henrique N. Cabral; Peter Bossier; Sara C. Novais (Reviews in Aquaculture, 2018)
Aquaculture production is expanding rapidly around the world. To tackle rising production and species diversity issues, innovations in the field of aquaculture feeds, breeding, disease management and other improvements must be addressed. In this framework, the study of epigenetic mechanisms behind different aquaculture rearing processes presents great opportunities. The transcriptional impact of epigenetic modifications, triggered by environmental stimuli, has been shown to influence the organism's phenotype. Therefore, understanding the environmental‐induced epigenetic markers related to disease resistance or other economically important traits will allow the establishment of favourable breeding conditions with increased economical revenue. Several studies have shown epigenetic effects in various species, induced by different rearing conditions, with benefits for the organisms and evidences for heritability of the acquired adaptive phenotypic traits across generations, making these studies even more relevant in a production context. These studies have demonstrated the great potential of epigenetics to positively induce disease resistance, stress tolerance and attain better sex ratios in the aquatic organism. Also, in the field of nutritional epigenetics, the possibility of early nutritional programming to improve the performance of broodstock or even the long‐term performance of their progeny has been suggested. In sum, an increased understanding of epigenetic mechanisms in economically important species, and the epigenetic markers leading to the most favourable phenotypic traits, will contribute to the expansion of economically viable commercial aquaculture industries. The major epigenetic mechanisms and respective analysis methods, as well as the state of the art and potential applications in aquaculture, are addressed in this review.

Attraction and repulsion of mobile wild organisms to finfish and shellfish aquaculture: a review - Myriam D. Callier; Carrie J. Byron; David A. Bengtson; Peter J. Cranford; Stephen F. Cross; Ulfert Focken; Henrice M. Jansen; Pauline Kamermans; Anders Kiessling; Thomas Landry; Francis O'Beirn; Erik Petersson; et al. (Reviews in Aquaculture, 2018)
Knowledge of aquaculture–environment interactions is essential for the development of a sustainable aquaculture industry and efficient marine spatial planning. The effects of fish and shellfish farming on sessile wild populations, particularly infauna, have been studied intensively. Mobile fauna, including crustaceans, fish, birds and marine mammals, also interact with aquaculture operations, but the interactions are more complex and these animals may be attracted to (attraction) or show an aversion to (repulsion) farm operations with various degrees of effects. This review outlines the main mechanisms and effects of attraction and repulsion of wild animals to/from marine finfish cage and bivalve aquaculture, with a focus on effects on fisheries‐related species. Effects considered in this review include those related to the provision of physical structure (farm infrastructure acting as fish aggregating devices ( FAD s) or artificial reefs ( AR s), the provision of food (e.g. farmed animals, waste feed and faeces, fouling organisms associated with farm structures) and some farm activities (e.g. boating, cleaning). The reviews show that the distribution of mobile organisms associated with farming structures varies over various spatial (vertical and horizontal) and temporal scales (season, feeding time, day/night period). Attraction/repulsion mechanisms have a variety of direct and indirect effects on wild organisms at the level of individuals and populations and may have implication for the management of fisheries species and the ecosystem in the context of marine spatial planning. This review revealed considerable uncertainties regarding the long‐term and ecosystem‐wide consequences of these interactions. The use of modelling may help better understand consequences, but long‐term studies are necessary to better elucidate effects.

Disease reduction in aquaculture with genetic and genomic technology: current and future approaches - Ahmed Elaswad; Rex Dunham (Reviews in Aquaculture, 2018)
Reduction in the occurrence and severity of disease in aquaculture would improve the productivity, profitability, efficiency and welfare of aquacultural fish. Genetic approaches that have been successfully implemented in aquaculture to enhance disease resistance and reduce disease incidence include classical selection, genetic marker‐assisted selection, intraspecific crossbreeding, interspecific hybridization and transgenesis. The rate and speed of improvement in disease resistance varies from one genetic enhancement programme to another. Genome editing with zinc finger nucleases ( ZFN s), transcription activator‐like effector nucleases ( TALEN s) and clustered regularly interspaced short palindromic repeats ( CRISPR s)‐ CRISPR ‐associated protein 9 (Cas9) opens avenues for targeted genome modifications. This technology can be applied in aquaculture to manipulate disease‐resistance genes by means of gene knock‐in, gene knockout and regulation of gene expression. The maximum rate of improvement can be achieved by combining different genetic enhancement programmes. Here, we present a review for the current and future prospect of disease reduction in aquaculture with genetic and genomic technologies.

Issues of aquatic experimentation in research on marine finfish larval production in Europe and North America - Ove Nicolaisen (Reviews in Aquaculture, 2018)
The aim of this review was to examine practices in academic research focusing on production of larvae of European marine fish species. The literature spanned peer‐reviewed articles over the years 1977–2014 for the main commercially produced marine species: Atlantic cod, halibut, sea bream, sea bass and turbot. Search hits were categorized into the main themes basic biology, natural habitat studies and aquaculture, and the latter theme further subdivided into nutrition, health, reproduction and production factor studies. In total, 74 of the production factor studies were thoroughly examined in terms of overall research structure, study designs, methods, analyses and reporting practices. A picture of a fragmented whole with many isolated contributors and limited cooperation appeared, and despite the multivariate nature and high complexity of the area, isolated and low replicated studies focusing on one variable at the time dominated. Randomization and blinding procedures were rarely accounted for, and a need to standardize practical conduct of research in terms of physical infrastructure, biological material used, control of tank environment, sampling, tank tending and response measurements appeared. Issues of statistical analysis were also apparent, spanning the choice of main techniques and follow‐up contrast procedures and Pseudoreplication. Additionally, the reporting of designs, analyses and results was often incomplete. Consequences of the different issues are discussed, and possible remedies proposed. The findings are in accordance with conclusions from contemporary studies addressing scientific quality and methodological issues at other areas of research.

Use of native and non‐native shrimp (Penaeidae, Dendrobranchiata) in world shrimp farming - Rafael Fernández de Alaiza García Madrigal; Ubiratã de Assis Teixeira da Silva; Camila Prestes dos Santos Tavares; Eduardo Luis Cupertino Ballester (Reviews in Aquaculture, 2018)
The 2013 global farmed shrimp production totalled 4.3 million tons, whereas the production of Litopenaeus vannamei as non‐native species represented the 64% of that amount. The risks of introducing non‐native or exotic species are a growing environmental concern. Therefore, the objective of this study was to discuss updated information about the introduction of non‐native species and to evaluate the efficiency indicators of non‐native species in contrast to native ones. The results of a systematic revision of the publications about shrimp farming are presented, comparing the zootechnical performance of native and non‐native species, with the use of meta‐analysis tools. The conducted search returned 4680 results, corresponding to the articles that included one of the criteria previously established by the present work. Seven publications, which included 22 studies, met the requirements for the meta‐analysis. The effect size calculated was positive, meaning that, according to the considered data, the use of non‐native species resulted generally in higher values of growth rate in relation to the native species observed. Other aspects like the emergence and dissemination of the main viral diseases affecting global shrimp farming were also revised. We conclude that, although the advantages of using non‐native species, especially L. vannamei , over native species are clear, there are enough compelling evidences to support the viability of small‐scale native species farming. We also discussed why big companies, governments and associations related to the production and commerce of farmed shrimp should finance and support the development of native species farming.

Vertebral abnormalities in free‐living Chinook salmon ( Oncorhynchus tshawytscha , Walbaum) in New Zealand - Peter S. Davie; Seumas P. Walker; Matthew R. Perrott; Jane E. Symonds; Mark Preece; Adelbert De Clercq; John S. Munday (New Zealand Journal of Marine and Freshwater Research, 2018)
Spinal abnormalities are common in farmed Chinook Salmon in New Zealand. We report spinal abnormalities in adult Chinook salmon which were predominantly hatchery reared and released as smolts and which we term free‐living. We compare these to rates seen in farmed New Zealand salmon. 101 free‐living adult salmon were radiographically assessed for spinal curvatures (lordosis, kyphosis, scoliosis; LKS) and other vertebral abnormalities. Severity of abnormality was assessed on a three‐point scale. Abnormal vertebral bodies were detected in 88.1% of free‐living salmon. Spinal curvatures were the most common abnormality type with 83.2% of fish showing this abnormality but only one free‐living Chinook had LKS of severity greater than 1. Farmed Chinook salmon are reported to have LKS rates of 29% with 18% of LKS abnormalities of severity greater than 1. These results suggest that free‐living Chinook salmon frequently develop spinal abnormalities, but these abnormalities are less severe than those observed in farmed salmon.

Molecular characterisation of the complete nuclear ribosomal DNA sequence of the blacklip abalone Haliotis rubra - Zhansheng Guo; Leng Han; Yi Ding; Xuguang Hou; Zhenlin Liang (New Zealand Journal of Marine and Freshwater Research, 2018)
Genes encoded in nuclear ribosomal DNA (nrDNA), which comprise a multi‐family of genes with tandem repeat units, play an important role in nucleolus formation. In the present study, we sequenced and analysed the complete rDNA sequence of an economically important shellfish in Australia, Haliotis rubra . The single rDNA unit measured 9881 base pairs (bp) in length and included the following elements in order: 18S rRNA (1858 bp), internal transcribed spacers (ITS, 756 bp), 28S rRNA (3413 bp) and an intergenic spacer (IGS, 3854 bp). The phylogenetic tree was constructed using abalone ITS sequences; here, the relationship revealed that abalone species within the same region and with same chromosome number tended to cluster within a clade. The positions of putative transcription termination and RNA transcription initiation sites were predicted in the IGS region. A comparative sequence complexity analysis and dot plots revealed a high level of variability in the IGS.

Otolith microchemistry indicates regional phylopatry in the larval phase of an amphidromous fish ( Gobiomorphus hubbsi ) - Manna L. Warburton; Matt G. Jarvis; Gerard P. Closs (New Zealand Journal of Marine and Freshwater Research, 2018)
Knowledge of stock structure is key for the effective management of any fish species. Amphidromous fish, which live and spawn in freshwater but spend a pelagic larval period at sea, have typically been assumed to disperse widely during their larval phase, resulting in populations being sourced from a single unstructured larval pool. We used otolith microchemical analysis to examine the stock structure of bluegill bully ( Gobiomorphus hubbsi ), a declining amphidromous eleotrid endemic to New Zealand, along the west coast of South Island, New Zealand. Some drainages – even those in close proximity (c. 20 km) – were readily distinguishable based on otolith trace element concentrations, while little structure was evident between other geographically disparate locations. These results indicate that, at least in some cases, locally retained larvae, rather than a single unstructured larval pool, dominates recruitment. Management of bluegill bully and other amphidromous species must therefore consider the possibility of regionally distinct populations.

Managing land‐use effects on Northland dune lakes: lessons from the past - Tom Stephens; Paul Augustinus; Brett Rip; Patricia Gadd; Atun Zawadski (New Zealand Journal of Marine and Freshwater Research, 2018)
The Northland region of New Zealand includes numerous high‐value, macrophyte‐dominated dune lakes. Recent water policy reforms offer limited guidance on managing for aquatic macrophytes. In addition, dune lake histories are poorly known as regular monitoring dates to 2005 AD. Here, ca. 4000 years of lake functional behaviour is reconstructed from sedimentary archives in two Northland dune lakes (Humuhumu and Rotokawau). Results demonstrated that macrophyte dominance is sensitive to catchment erosion and hydrological drawdown. Degradation of macrophyte communities occurred in the nineteenth and twentieth centuries, earlier at Lake Humuhumu than Lake Rotokawau (post‐1880 AD and post‐1930 AD, respectively). In both lakes, increased erosional influx reduced macrophyte productivity, before later increases to wider trophic state (post‐1970 AD). Lake‐level decline is linked to increased nutrient loading at Lake Rotokawau but less so, Lake Humuhumu which is more strongly groundwater‐fed. In Northland dune lakes, water‐level reduction and erosional influx from land use have driven macrophyte degradation.

Assessing sperm membrane viability using flow cytometry in farmed New Zealand giant kokopu Galaxias argenteus - Johnston Pearce; Armagan Sabetian; Liz‐Marie Keyser; Sheng Wang; Jun Lu (New Zealand Journal of Marine and Freshwater Research, 2018)
We employed flow cytometry to assess plasma membrane viability of sperm cells in farmed giant kokopu Galaxias argenteus , an endemic amphidromous New Zealand fish. Specifically, the variables of fish size (TL mm) and weight (grams) were assessed against sperm viability. We found no significant difference ( P G. argenteus . This study shows that flow cytometry is an effective, accurate and rapid method for analysing sperm viability in G. argenteus .

Diatom assemblages from surface sediments of the Río de la Plata estuary, Uruguay - Laura Perez; Ernesto Brugnoli; Pablo Muniz; Inés Sunesen; Eugenia A. Sar; Carolina Crisci; Carolina Cuña; Felipe García‐Rodríguez (New Zealand Journal of Marine and Freshwater Research, 2018)
The Río de la Plata estuary (RdlP) exhibits environmental gradients associated with the freshwater input and oceanic water intrusion. The aim of this study was to assess diatom species distribution in surface sediment samples related to such environmental gradients. The internal section of RdlP was dominated by Aulacoseira spp . , Eunotia spp., Staurosirella martyi , Actinocyclus normanii and Thalassiosira baltica , indicatives of low salinity levels and high trophic conditions, associated with the riverine and estuarine regimes. The external section was dominated by Coscinodiscus radiatus , Thalassiosira spp., Paralia sulcata , Cyclotella striata , among other marine taxa, indicatives of high salinity and low trophic conditions, associated with the influence of the Southwestern Atlantic Ocean. Furthermore, the intermediate section presents a mixture of both diatom groups representing mixing conditions. The observed diatom species groups capture fairly well the RdlP environmental variability and can be reliably used for paleoenvironmental studies in this and other similar estuarine systems.

Climate change projections for the surface ocean around New Zealand - Cliff S. Law; Graham J. Rickard; Sara E. Mikaloff‐Fletcher; Matt H. Pinkerton; Erik Behrens; Steve M. Chiswell; Kim Currie (New Zealand Journal of Marine and Freshwater Research, 2018)
The future status of the surface ocean around New Zealand was projected using two Earth System Models and four emission scenarios. By 2100 mean changes are largest under Representative Concentration Pathway 8.5 (RCP8.5), with a +2.5°C increase in sea surface temperature, and decreases in surface mixed layer depth (15%), macronutrients (7.5–20%), primary production (4.5%) and particle flux (12%). Largest macronutrient declines occur in the eastern Chatham Rise and subantarctic waters to the south, whereas dissolved iron increases in subtropical waters. Surface pH projections, validated against subantarctic time‐series data, indicate a 0.335 decline to ∼7.77 by 2100. However, projected pH is sensitive to future CO 2 emissions, remaining within the current range under RCP2.6, but decreasing below it by 2040 with all other scenarios. Sub‐regions vulnerable to climate change include the Chatham Rise, polar waters south of 50°S, and subtropical waters north of New Zealand, whereas the central Tasman Sea is least affected.

Estimated calving interval for the New Zealand southern right whale ( Eubalaena australis ) - Anthony Raphael Davidson; William Rayment; Steve M Dawson; Trudi Webster; Elisabeth Slooten (New Zealand Journal of Marine and Freshwater Research, 2018)
Southern right whales ( Eubalaena australis ) were widespread in New Zealand waters before commercial whaling in the nineteenth century caused drastic declines in their abundance and distribution. Following the cessation of whaling, the population has been recovering and is now slowly recolonising its former range. Estimates of population demographics, including reproductive output, are essential for predicting the trajectory of this population. We gathered photo‐identification data on female southern right whales during annual field trips to the Auckland Islands, the principal calving area in New Zealand waters. Forty‐five calving intervals were observed between 2006 and 2013 (mean interval = 3.31 years, 95% CI = 3.06–3.57). Incorporating the effects of possible missed calving events produced a plausible range of mean calving intervals from 3.17 to 3.31 years. Our results suggest that the calving interval of New Zealand southern right whales is similar to that found in populations elsewhere.

Anthropogenic increases of catchment nitrogen and phosphorus loads in New Zealand - Ton H. Snelder; Scott T. Larned; Rich W. McDowell (New Zealand Journal of Marine and Freshwater Research, 2018)
Spatial regression models were used to predict yields (kg ha −1 yr −1 ) of nitrogen (N) and phosphorus (P) discharged from catchments throughout New Zealand under natural and current conditions. The models were derived using loads (kg yr −1 ) of TN, NO 3 ‐N, TP and DRP calculated for 592 river water quality monitoring sites. Anthropogenic increases in yields above natural levels were associated with the proportions of catchments occupied by the intensive agricultural land cover and were unevenly distributed across regions. Anthropogenic increases in national loads of TN, NO 3 ‐N, TP and DRP exported to the ocean were 74%, 159%, 48% and 18%, respectively. Increases in loads exported to the ocean varied considerably at smaller scales, with catchments having significant load increases between 4‐ and 26‐fold for N and 6‐ to 9‐fold for P. Predictions of yields and loads reported here have utility in the development of strategies to manage nutrients.

Issue Information (Reviews in Aquaculture, 2018)

Chinese Abstracts (Reviews in Aquaculture, 2018)

Risk of waterborne virus spread – review of survival of relevant fish and crustacean viruses in the aquatic environment and implications for control measures - Birgit Oidtmann; Peter Dixon; Keith Way; Claire Joiner; Amanda E. Bayley (Reviews in Aquaculture, 2018)
Aquatic animal diseases are a major constraint for increasing aquaculture production. Understanding the contribution of pathogen spread from infected aquaculture sites is critical in devising control measures in the event of an outbreak. We have reviewed the available literature on the persistence in the aquatic environment of several important viral pathogens of fish and crustaceans. These include infectious haematopoietic necrosis virus, viral haemorrhagic septicaemia virus, infectious salmon anaemia virus, koi herpes virus, epizootic haematopoietic necrosis virus and infectious pancreatic necrosis virus, white spot syndrome virus ( WSSV ), Taura syndrome virus and yellow head virus. Some trends were common to all viruses: (i) viability declined with increasing temperature (at temperatures above 0°C); (ii) higher biological loading in water correlated with reduction in detectable viable viruses; and (iii) virus decay in water is a function of time. Most aquatic animal viruses ( AAV s) remained viable for several days or weeks. WSSV is particularly stable. Comparison of studies investigating survival parameters was sometimes difficult because of the different methods employed and different ways in which the data were presented. Data gaps are identified and experimental methods employed for testing critically assessed. The information presented in this review is directly relevant to design effective control measures for AAV s and to explore measures that reduce the economic impact of disease caused by these important pathogens.

Applications of genotyping by sequencing in aquaculture breeding and genetics - Diego Robledo; Christos Palaiokostas; Luca Bargelloni; Paulino Martínez; Ross Houston (Reviews in Aquaculture, 2018)
Selective breeding is increasingly recognized as a key component of sustainable production of aquaculture species. The uptake of genomic technology in aquaculture breeding has traditionally lagged behind terrestrial farmed animals. However, the rapid development and application of sequencing technologies has allowed aquaculture to narrow the gap, leading to substantial genomic resources for all major aquaculture species. While high‐density single‐nucleotide polymorphism ( SNP ) arrays for some species have been developed recently, direct genotyping by sequencing ( GBS ) techniques have underpinned many of the advances in aquaculture genetics and breeding to date. In particular, restriction‐site associated DNA sequencing ( RAD ‐Seq) and subsequent variations have been extensively applied to generate population‐level SNP genotype data. These GBS techniques are not dependent on prior genomic information such as a reference genome assembly for the species of interest. As such, they have been widely utilized by researchers and companies focussing on nonmodel aquaculture species with relatively small research communities. Applications of RAD ‐Seq techniques have included generation of genetic linkage maps, performing genome‐wide association studies, improvements of reference genome assemblies and, more recently, genomic selection for traits of interest to aquaculture like growth, sex determination or disease resistance. In this review, we briefly discuss the history of GBS , the nuances of the various GBS techniques, bioinformatics approaches and application of these techniques to various aquaculture species.

Sugars as supplemental cryoprotectants for marine organisms - Sujune Tsai; Gabriella Chong; Pei‐Jie Meng; Chiahsin Lin (Reviews in Aquaculture, 2018)
Cryopreservation has been extensively used in various mega‐industries and has recently been applied in genetic banking for conservation purposes. Compared with conventional cell preservation methods, cryopreservation can maintain the viability of cryopreserved cells for an indefinite time at a relatively lower cost and lesser manpower, with lower probabilities of contamination and genetic changes. This study presents the crucial role of sugar, a cryoprotectant supplement in cryopreservation. Sugar molecules typically interact with the lipid bilayer during the freezing phase to maintain plasma membrane integrity when cells undergo dehydration. When combined with other permeable cryoprotectants such as glucose with methanol and trehalose with dimethyl sulphoxide, sugar prolongs and enhances cellular post‐thaw viability. Moreover, terrestrial and marine organisms have benefited from the inclusion of sugar in the cryopreservation protocol. For wide range of cells such as the sperm, oocytes, embryos and larvae of marine vertebrates and invertebrates, as well as marine algae, cryopreservation with sugar produced positive results compared with cryopreservation without sugar. Not all sugar is beneficial, and the type and concentration of sugar should be applied according to the species. Moreover, the freezing method may also affect the function of sugar. Nevertheless, understanding the role of sugar in cryobiology and conducting a preliminary trial of sugar for cryopreserving cells would benefit future research on cryopreservation.

Plant essential oils as fish diet additives: benefits on fish health and stability in feed - Fernando J. Sutili; Delbert M. Gatlin; Berta M. Heinzmann; Bernardo Baldisserotto (Reviews in Aquaculture, 2018)
Nutritional strategies focused on the use of phytochemicals as modulators of immunological and physiological responses, as well as antistress and antioxidant therapies and health promoters of the gastrointestinal tract have attracted increased interest in animal production. Over the past two decades, several studies have reported positive results of using plant essential oils ( EO s) as dietary additive in several farm animal species. Recently, these nutritional alternatives have been evaluated and reported in fish production in order to enhance the resistance to diseases and prevent outbreaks, as well as to improve fish growth, animal welfare and feed utilization. However, despite the diverse and relevant biological activities reported, these phytochemicals are composed of often unstable and volatile molecules, which makes the chemical and physical characteristics of the EO s important aspects to be considered in fish nutrition research. This review summarizes the current knowledge regarding the use of plant EO s as fish dietary additives, focusing on their potential as modulators of the gut bacterial community and discussing some aspects regarding their stability in feeds.

Progress in fish gastrointestinal microbiota research - An R. Wang; Chao Ran; Einar Ringø; Zhi G. Zhou (Reviews in Aquaculture, 2018)
The gastrointestinal (GI) microbiota of vertebrates plays critical roles in nutrition, development, immunity and resistance against invasive pathogens. In the past decade, research of the GI microbiota of mammals has drastically increased our knowledge on the microbiota and their relationship with health and disease. However, our understanding of fish intestinal microbiota is limited. This review provides an overview of research on fish gut microbiota, including microbial composition, formation, factors that affect the GI microbes and characteristics of fish intestinal microbiota compared with human and mice. Further, the updated research on gnotobiotic zebrafish is elaborated and the insights gained on functions of the fish intestinal microbiota are discussed. Understanding the intestinal microbiota of fish will guide the development of probiotics, prebiotics and hopefully probiotic effectors as novel additives to improve the health of fish.

Use of lumpfish for sea‐lice control in salmon farming: challenges and opportunities - Adam Powell; Jim W. Treasurer; Craig L. Pooley; Alex J. Keay; Richard Lloyd; Albert K. Imsland; Carlos Garcia de Leaniz (Reviews in Aquaculture, 2018)
Efficient sea‐lice control remains one of the most important challenges for the salmon farming industry. The use of wrasse (Labridae) as cleaner fish offers an alternative to medicines for sea‐lice control, but wrasse tend to become inactive in winter. Lumpfish ( Cyclopterus lumpus ) continue to feed on sea‐lice at low temperatures, and commercial production has escalated from thousands of fish in 2010 to well over 30 million juveniles deployed in 2016. However, production still relies on the capture of wild broodstock, which may not be sustainable. To meet global industry needs, lumpfish production needs to increase to reach c. 50 million fish annually and this can only come from aquaculture. We review current production methods and the use of lumpfish in sea cages and identify some of the main challenges and bottlenecks facing lumpfish intensification. Our gap analysis indicates that the areas in most need of research include better control of maturation for year‐round production; formulation of appropriate diets; artificial selection of elite lines with desirable traits; and development of vaccines for certified, disease‐free juvenile production. The welfare of farmed lumpfish also needs to be better quantified, and more information is needed on optimal densities and tank design. Finally, the risk of farmed lumpfish escaping from net pens needs to be critically assessed, and we argue that it might be beneficial to recover cleaner fish from salmon cages after the production cycle, perhaps using them as broodstock, for export to the Asian food markets or for the production of animal feeds.

Protein phosphorylation and ions effects on salmonid sperm motility activation - Kelly Dumorné; Elías Figueroa; Jacky Cosson; Manuel Lee‐Estevez; Patricio Ulloa‐Rodríguez; Iván Valdebenito; Jorge G. Farías (Reviews in Aquaculture, 2018)
Sperm motility is considered as a key factor allowing determination of semen quality and predicts fertilizing capacity. In many fish species, the spermatozoa are immotile in the testes and seminal plasma, and motility is induced when they are released in the aqueous environment. Initiation and activation of sperm motility are prerequisite processes for the contact and fusion of male and female gametes at fertilization. Many proteins are involved in the activation of sperm motility in many species. Cell signalling for the initiation of sperm motility in the salmonid fish has drawn much attention during the last two decades. In some species, protein phosphorylation process was shown to be involved in flagellar motility regulation. Hyperpolarization of the sperm membrane induces synthesis of cAMP (cyclic AMP ), which triggers further cell signalling processes, such as cAMP ‐dependent protein phosphorylation that finally initiates sperm motility in salmonid fish. Ions such as Na + , K + and Ca 2+ play also an important role in the activation of sperm motility in many species, more specifically in salmonids. Salmonid fish sperm motility can be suppressed by millimolar concentrations of extracellular K + , and dilution of K + upon spawning is enough to trigger the cAMP ‐dependent signalling cascade leading to motility initiation. This review aims to update the present knowledge about the roles of ions and protein phosphorylation process in the sperm motility activation in salmonids.

A comprehensive review of Vibrio ( Listonella ) anguillarum : ecology, pathology and prevention - Michael E. Hickey; Jung‐Lim Lee (Reviews in Aquaculture, 2018)
Vibrio ( Listonella ) anguillarum is a marine bacteria that is pathogenic to a number of aquatic organisms including several species which are important to the aquaculture industry. Organisms that are infected by V. anguillarum are diagnosed with vibriosis which can be lethal in a matter of days. Vibriosis can be particularly devastating to aquaculture businesses and measures of prevention or treatment are generally quite expensive. Efforts to understand and control V. anguillarum virulence have been of high‐priority among international aquatic research studies. The knowledge that has accumulated as a result of this collective research effort is reviewed in this article.

Astaxanthin as feed supplement in aquatic animals - Keng Chin Lim; Fatimah Md. Yusoff; Mohamed Shariff; Mohd Salleh Kamarudin (Reviews in Aquaculture, 2018)
Astaxanthin is a high value keto‐carotenoid pigment renowned for its commercial application in various industries comprising aquaculture, food, cosmetic, nutraceutical and pharmaceutical. Among the verified bio‐resources of astaxanthin are red yeast Phaffia rhodozyma and green alga Haematococcus pluvialis . The supreme antioxidant property of astaxanthin reveals its tremendous potential to offer manifold health benefits among aquatic animals which is a key driving factor triggering the upsurge in global demand for the pigment. Numerous scientific researches devoted over a number of years have persistently demonstrated the instrumental role of astaxanthin in targeting several animal health conditions. This review article evaluates the current best available evidence to judge the beneficial usage of astaxanthin in aquaculture industry. Most apparent is the profound effect on pigmentation, where astaxanthin is frequently utilized as an additive in formulated diets to boost and improve the coloration of many aquatic animal species, and subsequently product quality and price. Moreover, the wide range of other physiological benefits that this biological pigment confers to these animals is also presented which include various improvements in survival, growth performance, reproductive capacity, stress tolerance, disease resistance and immune‐related gene expression.

Aquaculture of two commercially important molluscs (abalone and limpet): existing knowledge and future prospects - Anthony Mau; Rajesh Jha (Reviews in Aquaculture, 2018)
Molluscan aquaculture produces the most food fish by volume in the global mariculture market. The historical, cultural and ecological value of molluscs makes them a highly sought‐after delicacy in many regions of the world. Specifically, the aquaculture of abalone and that of limpets are two key industries with striking similarities and importance within the context of food production and food security. In this review, the current knowledge of these two commercially important seafood species is explored for a comprehensive understanding of its aquaculture status. The various culture methods and systems, animal nutrition and necessary improvements are discussed for abalone and limpets, respectively. For abalone, the knowledge base is extensive and some reviews have been written to compile essential information regarding different aspects of this healthy industry. For limpets, there is a small collection of aquaculture literature, and this is, to the authors’ knowledge, the first comprehensive review of the research. Our goal was to reveal, within the area of aquaculture research, the current status of both abalone and limpet industries while exposing their respective knowledge gaps for appropriate development of new technologies. With a firm understanding of these molluscs, the production of abalone and limpet will be sustainable for the long term.

Toxic effects of nitrite on freshwater organisms: a review - Hana Kocour Kroupová; Olga Valentová; Zdeňka Svobodová; Pavel Šauer; Jana Máchová (Reviews in Aquaculture, 2018)
High nitrite concentrations may occur mainly in recirculating aquaculture systems, but can also be found under certain conditions in natural waters. Among studied freshwater organisms, molluscs and worms followed by fish are the most resistant to nitrite. On the other hand, crustaceans and aquatic insects followed by amphibians are the most sensitive. Wide interspecific differences in nitrite susceptibility can be found within freshwater insects, crustaceans and amphibians. Chloride concentration in water is supposed to be the most important factor influencing nitrite toxicity. Generally, a positive chloride effect on nitrite toxicity reduction can be expected in all aquatic animals (or their early stages) employing gills for breathing and ion exchange. This phenomenon has already been observed in an amphipod ( Eulimnogammarus toletanus , Pinkster & Stock), a planarian ( Polycelis felina , Dalyell), two species of crayfish, several fish species and in amphibians in early development stages. A relatively huge amount of data on nitrite effects is available for fish, but other freshwater organisms were less frequently studied. Information on chronic effect of nitrite is nearly completely missing.

RNA interference in shrimp and potential applications in aquaculture - Dung Viet Nguyen; Olivier Christiaens; Peter Bossier; Guy Smagghe (Reviews in Aquaculture, 2018)
As the RNA interference mechanism was discovered, researchers have made huge strides in unravelling biological mechanisms at the gene level in a wide range of organisms. RNA i is a simple and rapid method that allows silencing gene expression at the post‐transcriptional level and is triggered by the introduction of double‐stranded RNA into the cell, leading to the degradation of the corresponding mRNA . In this review, we will provide an overview of successful RNA i experiments to date in Crustacea, and shrimp in particular, with special focus on various potential applications of RNA interference in research and aquaculture. An important aspect of RNA i in any species is the delivery of the double‐stranded RNA and the barriers that have to be overcome to get the ds RNA into the target cells. Different options, experimental procedures, success rates and challenges in using RNA i are discussed in this review.

Overview of 3 year precommercial seafarming of Macrocystis pyrifera along the Chilean coast - Carolina Camus; Javier Infante; Alejandro H. Buschmann (Reviews in Aquaculture, 2018)
Chile is one of the main producers of seaweeds in the world; however, most of the production comes from harvesting natural beds and only 2.4% from cultures, dominated by the agarophyte Gracilaria chilensis . One of the most exploited resources is the giant kelp Macrocystis pyrifera , which is sold fresh for abalone feed and dry for alginate extraction. Recently, new possible markets are developing for this species, for example human consumption and biofuel/chemical production that could increase the demand and justify the development of a commercial cultivation system. The objective of this work was to present the recent development of the seafarming of M. pyrifera in Chile, focusing on the fundamental determinants of productivity in cultivated systems and the identification of the binding constraints to productivity. Three experimental plots (up to 21 Ha) were designed and deployed in three study areas (Caldera in northern Chile and Quenac and Ancud in southern Chile) to test different environmental conditions. During a period of 3 years, sporophytes produced in an indoor hatchery were deployed monthly, at different densities, and followed until harvest. Environmental parameters and biomass were monitored on a monthly basis. Our findings demonstrate the feasibility of Macrocystis seafarming on a large scale in Chile. Important differences in yield were observed between the study areas associated with either environmental physical or biological factors, such as the presence of herbivores. Our best production cycle reached 124 WMT Ha −1 month −1 in southern Chile, and the worst, less than 20 WMT Ha −1 month −1 in northern Chile. Finally, some direct and indirect constrains were encountered, including seeding season and depth, and the presence of pests and diseases, that are discussed.

A meta‐analysis of integrated multitrophic aquaculture: extractive species growth is most successful within close proximity to open‐water fish farms - Daniel Kerrigan; Coleen C. Suckling (Reviews in Aquaculture, 2018)
Fish farming in open water releases dissolved and particulate waste (inorganic and organic) into the surrounding marine environment. To reduce this environmental impact, commercial extractive species can be grown alongside to utilize and reduce this waste, a technique known as integrated multitrophic aquaculture ( IMTA ). Information is lacking on whether (i) IMTA is generally successful with respect to extractive species growth responses and (ii) at what spatial scale they can be cultivated from fish cage nutrient sources. Focussing on bivalves and macroalgae as extractive species, this study uses a meta‐analysis approach to summarize and conclude peer‐reviewed data on IMTA to address these information gaps. We show that there are clear benefits to integrating bivalves and macroalgae with fish farms. Bivalves grown within, and relatively near, fish cages (0 m and 1–60 m distance categories, respectively) showed significantly higher biomass production relative to controls compared to those grown at larger spatial scales (61+ m). However, biomass production of macroalgae was significantly higher than controls only within close proximity to fish cages (0 m). This information shows increased extractive species production is generally greatest at relatively small spatial scales. It also highlights the need for more site‐specific information (e.g. seawater parameters, hydrodynamics, food supply, farm capacity) in future studies. The allocation of control sites and locating these at suitable distances (>1–8 km) from fish farm effluent sources to avoid fish farm nutrient contamination are also recommended.

Influence of age, size and condition factor on lipid concentration in the snapper Chrysophrys auratus - Hamish Allen; Armagan Sabetian; Martin Bader; Tom Rowlands (New Zealand Journal of Marine and Freshwater Research, 2018)
Survival, growth rates and functionality of larvae have been hypothesised to correlate with higher lipid provisioning in older teleosts. To test the lipid provisioning part of this hypothesis, we investigated the total and relative (mg/g) lipid (triglyceride) concentration in both the source (liver) and sink (gonad) lipidation organs of female snapper Chrysophrys auratus across age, size and condition factor throughout its spawning season. Age, size and condition factor had little discernible effect on the total or relative lipid concentration in either liver or gonadal tissue. Therefore, if oocyte quality (based on triglyceride concentration) is comparable across a population, research on the relationship between lipidomics and reproductive success needs to move beyond highlighting correlations to elucidating causation by focusing on the biochemical mechanisms of egg quality and larval survival, identifying maternal parameters associated with consistent lipid provisioning, and partitioning of phenotypic and genotypic maternal influences.

Erratum (New Zealand Journal of Marine and Freshwater Research, 2018)

Ocean acidification in New Zealand waters: trends and impacts - Cliff S. Law; James J. Bell; Helen C. Bostock; Chris E. Cornwall; Vonda J. Cummings; Kim Currie; Simon K. Davy; Malindi Gammon; Christopher D. Hepburn; Catriona L. Hurd; Miles Lamare; Sara E. Mikaloff‐Fletcher; et al. (New Zealand Journal of Marine and Freshwater Research, 2018)
The threat posed by ocean acidification (OA) to the diversity and productivity of New Zealand marine ecosystems is assessed in a synthesis of published trends and impacts. A 20‐year time series in Subantarctic water, and a national coastal monitoring programme, provide insight into pH variability, and context for experimental design, modelling and projections. A review of the potential impact of changes in the carbonate system on the major phyla in New Zealand waters confirms international observations that calcifying organisms, and particularly their early life‐history stages, are vulnerable. The synthesis considers ecosystem and socio‐economic impacts, and identifies current knowledge gaps and future research directions, including mechanistic studies of OA sensitivity. Advanced ecosystem models of OA, that incorporate the indirect effects of OA and interactions with other climate stressors, are required for robust projection of the future status of New Zealand marine ecosystems.

Census survey approach to quantifying īnanga spawning habitat for conservation and management - Shane Orchard; Michael J. Hickford (New Zealand Journal of Marine and Freshwater Research, 2018)
Here, we describe a methodology for quantifying the spawning habitat of īnanga ( Galaxias maculatus ), a protected native fish species. Our approach is demonstrated with a survey of the Heathcote/Ōpāwaho following the Canterbury earthquakes that produced unexpected findings. Spawning habitat was detected over a 2.5 km reach and the area occupied by spawning sites (75m 2 ) was much larger than in previous records (ca. 21m 2 ). Sites dominated by the invasive Phalaris arundinaceae were found to support high egg numbers. Spawning has not previously been recorded on this species and it is identified in the literature as a threat to spawning habitat. Considerable spatio‐temporal variation was also detected in the location of spawning sites and pattern of egg production. Together, these aspects illustrate the need for a comprehensive survey methodology to reliably quantify spawning habitat. The Heathcote/Ōpāwaho example shows the utility of our census approach for achieving this, and supporting habitat conservation objectives.

The biology, ecology and history of toheroa ( Paphies ventricosa ): a review of scientific, local and customary knowledge - P. M. Ross; M. P. Beentjes; J. Cope; W. P. de Lange; B. G. McFadgen; P. Redfearn; B. Searle; M. Skerrett; H. Smith; S. Smith; J. Te Tuhi; J. Tamihana; et al. (New Zealand Journal of Marine and Freshwater Research, 2018)
Toheroa ( Paphies ventricosa ) were formerly abundant on west and south‐facing New Zealand surf beaches. Harvesting of this surf clam was intense during the early to mid‐1900s, and populations declined to levels where harvesting was no longer viable. Despite having now been protected for 35–45 years, toheroa have failed to recover. This paper reviews the history of human interactions with toheroa and our understanding of their ecology, with a view to identifying knowledge requirements for management and restoration. Historical and legal documents pertaining to the use of marine resources are reviewed and scientific understanding compared with customary and local knowledge. We consider the factors that may be preventing toheroa recovery and make recommendations for research into life history, habitat requirements and the ecological consequences of changing land use. Management options are suggested to address the effects of vehicle use on beaches, poaching and the failings of the customary harvest system.

Responses of two temperate sponge species to ocean acidification - Tracey E. M. Bates; James J. Bell (New Zealand Journal of Marine and Freshwater Research, 2018)
There are still major gaps in our understanding of the impact of ocean acidification (OA) on some groups of organisms within different geographic regions. We investigated the effect of OA on two common and ecologically important temperate sponge species in New Zealand ( Tethya bergquistae and Crella incrustans ). Sponges were kept at pH 8 (control) and 7.6 for 4 weeks. Responses of the two species varied, with T. bergquistae kept at pH 7.6 showing some mortality in response to reduced pH and evidence of tissues necrosis. In contrast, only one C. incrustans died in the pH 7.6 treatment and showed little evidence of any tissue degradation. Only T. bergquistae showed evidence for physiological effects of reduced pH as respiration rates were generally higher in the pH 7.6 treatment. Our results provide preliminary evidence to support a general tolerance of temperate sponges to reduced pH, but that some species‐specific responses may exist.

Complete nuclear ribosomal DNA sequence analyses of the black‐footed abalone Haliotis iris - Zhansheng Guo; Xuguang Hou; Leng Han (New Zealand Journal of Marine and Freshwater Research, 2018)
The black‐footed abalone Haliotis iris is an economically important shellfish species in New Zealand. We successfully amplified, sequenced and analysed the complete nuclear ribosomal DNA (nrDNA) of H. iris . The length of the nrDNA was determined to be around 9.6 kb and included, in order, small subunit ribosomal RNA (nrSSU, 1858bp), internal transcribed spacer (ITS, 749 bp), large subunit ribosomal RNA (nrLSU, 3412bp) and an intergenic spacer (IGS, 3560–3662 bp). The nrLSU genes were identical in two individuals, whereas the nrSSU and ITS regions existed at three and four base differences, respectively. The IGS was more variable than the other nrDNA regions. A phylogenetic tree was constructed based on the ITS sequence datasets, which revealed that Haliotidae has two major subclades, mainly distributed in the North Pacific, Europe and Australia. The complete nrDNA sequence will be useful for the classification, phylogeny and breeding of this shellfish.

Long‐range dependence in the runoff time series of the most important Patagonian river draining to the Pacific Ocean - Rodrigo M. Montes; Renato A. Quiñones (New Zealand Journal of Marine and Freshwater Research, 2018)
The Baker River is the largest free‐flowing river in Chilean Patagonia. Long‐range dependence (LRD), a recognised hydrological property of river runoff worldwide, was detected for the Baker River runoff time series. Analyses were conducted on a monthly scale between 1961 and 2015 using the fractal and multifractal detrended fluctuation analysis methodology. A long‐range‐dependent Hurst coefficient ( H ) equal to 0.94 was obtained. A scaling range, which is the signature of LRD, was detected for the Baker River runoff time series between 1 and 5.25 years. Baker River runoff showed a strong correlation ( r = 0.96) with the Antarctic Oscillation (AAO) Index during the 2007–2015 period. The high storage capacity of Lake General Carrera, the size of the Baker River basin area and the dynamics of AAO are proposed as main factors that contribute to the emergence of LRD in the Baker River runoff time series.

Chinese Abstracts (Reviews in Aquaculture, 2018)

Issue Information (Reviews in Aquaculture, 2018)

Vitamin C supplementation to optimize growth, health and stress resistance in aquatic animals - Mahmoud A.O. Dawood; Shunsuke Koshio (Reviews in Aquaculture, 2018)
Vitamins are organic compounds that can be synthesized from other essential nutrients; however, they are required in trace amounts from an exogenous source for normal growth, reproduction and health. Vitamin C (ascorbic acid, AA) is an essential micronutrient for normal growth and physiological function of most aquatic animals. In terrestrial animal nutrition, vitamin C has recently spurred scientific interest because of the increasing knowledge on vitamin C involvement in gene expression, cell cycle and reproduction in mammals; in addition, recent advances in molecular biology techniques allow the more effective estimation of the effect of vitamin C on metabolism and physiology. In contrast, this information is scarce in aquatic animal nutrition, as studies have essentially focused on the estimation of minimum vitamin C requirement for maximum growth and immune response as well as for the formulation of least‐cost diet. This scarcity of information is also due to the lack of well‐established indicators of vitamin C status in aquatic organisms. The present review summarizes and discusses information about vitamin C sources, bioavailability, deficiency and requirement in aquatic animals to plan further studies. In the future, vitamin C nutrition studies in aquaculture should also include immune responses, histopathology of the gills, liver, gonad development, gamete quality and quantity, fecundity, larvae survival and gene expression. Dietary vitamin C requirements should be estimated at every life‐history stage of cultured species. All this information will allow a better understanding of the essentiality of vitamin C in aquatic animal growth, development, reproduction and health.

The spotted rose snapper ( Lutjanus guttatus Steindachner 1869) farmed in marine cages: review of growth models - Sergio G. Castillo‐Vargasmachuca; Jesús T. Ponce‐Palafox; Eulalio Arámbul‐Muñoz; Guillermo Rodríguez‐Domínguez; Eugenio Alberto Aragón‐Noriega (Reviews in Aquaculture, 2018)
The main purpose of this study was to review the growth models used in fish culture and demonstrate the benefit of using the most appropriate growth model for aquaculture studies. For this reason, another part of this study was to use a dataset from spotted rose snapper ( Lutjanus guttatus Steindachner, 1869) cultured in floating cages to determine what growth models were applicable to this species. A total of 558 weight‐at‐age data points from a commercial farm located near Nayarit, Mexico were used. The fish were cultured for 270 days in three cages of 125 m 3 capacity. The initial density was 25 fish m −3 , with an average weight of 2.07 ± 0.52 g. Four asymptotic models (von Bertalanffy growth model, a logistic model, the Gompertz growth model and the Ratkowsky modified model), three nonasymptotic models (exponential, power extended and persistence models) and three versions of the generalized Schnute model were selected as candidate models. The best model was selected based on the Akaike information criterion. The maximum log‐likelihood algorithm was used to parameterize the models considering a multiplicative error structure. The survival was 90%, and the average final weight was 429.84 ± 31.53 g. We concluded that the best model for describing the growth of spotted rose snapper farmed in marine floating cages was the Schnute model.

A revisit to fishmeal usage and associated consequences in Chinese aquaculture - Dong Han; Xiujuan Shan; Wenbing Zhang; Yushun Chen; Qingyin Wang; Zhongjie Li; Guofan Zhang; Pao Xu; Jiale Li; Shouqi Xie; Kangsen Mai; Qisheng Tang; et al. (Reviews in Aquaculture, 2018)
China has dominated global aquaculture production for more than two decades. Aquaculture production in China increased from 24.6 million metric tons (mmt) in 2000 to 47.5 mmt in 2014, an increment of 93.1%. Along with the fast‐growing aquaculture industry, aquafeed production in China increased from 5.1 mmt in 2000 to 19.0 mmt in 2014, an increment of 272.5%. However, despite the rapid increase in aquafeed production, the fishmeal usage in aquafeeds in China has remained stable over the years. Fishmeal imports into China remained relatively steady at 1.0–1.5 mmt per annum from 2000 to 2014. An often unacknowledged fact is that China contributes more than 60% to the world aquaculture production at a cost of only 25–30% of the world fishmeal output. This review attempts to explain why the fishmeal usage has not increased proportionately with the increasing aquafeed production in China from several angles: (i) the current status of fishmeal usage in Chinese aquaculture; (ii) the relationship between the decreasing dietary inclusions of fishmeal and improved feed techniques, especially the use of alternative protein sources for fishmeal; (iii) the dominance of Chinese aquaculture by low trophic level species of plants, filter feeders, herbivores and omnivores and consequent low demands for fishmeal; and (iv) the increasing price of fishmeal and the management of exploitation of wild fisheries in the main fishmeal exporting countries to China. The trends and prospects of fishmeal usage in the future in Chinese aquaculture and the associated consequences are also addressed. Like other countries, China is now actively developing both resource conservation‐based capture fisheries and environment‐friendly freshwater and marine aquaculture systems. Aquaculture will be the main source of aquatic food in the future and will also indirectly contribute to save the world wild fisheries, and China will be main player that will continue to contribute towards this end.

Direct application of ozone in aquaculture systems - Adam Powell; Jacob W.S. Scolding (Reviews in Aquaculture, 2018)
Ozone (O 3 ) is a powerful oxidant that has been used in both the aquaculture and water treatment industries to improve water quality and reduce pathogens during pretreatment, treatment of effluent, as a continual treatment during RAS operations, and for bivalve depuration. As ozone can be toxic to aquatic organisms, the technology has also been investigated to destroy invasive or nuisance species, and other research has also highlighted negative effects of residual ozone on water courses. Ozone and ozone‐produced oxidants used in aquaculture operations have therefore typically been removed from water prior to entry into tanks holding stock animals. However, a growing body of research has identified direct application of ozone, here defined as exposure of residual ozone and ozone‐produced oxidants to cultured species of finfish, shellfish and live feeds across various life stages. This approach appears to be increasingly employed as a beneficial technology due to proven enhancement of hygiene and water quality, provided dosages or concentrations are appropriate to maintain animal health and welfare. This review paper concentrates on the observed benefits and drawbacks of direct ozonation, influencing factors and future considerations for standardisation and uptake of the technology.

Use of bacterial subcellular components as immunostimulants in fish aquaculture - Sib Sankar Giri; Cheng Chi; Jin Woo Jun; Se Chang Park (Reviews in Aquaculture, 2018)
Aquaculture and fisheries products are expected to play a leading part in addressing the food necessities of the increasing human population. However, in intensive aquaculture, fish are exposed to stress conditions that deteriorate their immune systems, leading to increased disease vulnerability. These disease outbreaks have resulted in production losses and represent one of the key constraints in fish farming. Accordingly, aquaculture disease management efforts have concentrated on the establishment of environmental friendly and lasting methods. Recently, several studies have revealed that various bacteria (especially probiotics)‐derived cellular components might be used as promising immunostimulants in fish aquaculture. Such components curtail the risk concomitant with the use of antibiotics, chemotherapeutics, vaccines and probiotics. Among the various health advantages ascribed to bacterial cellular components, the modulation of specific and nonspecific immune responses, cytokine gene expression and anti‐pathogenic activities are most anticipated benefits. Their potential as vaccine adjuvants for fish culture has also been demonstrated. However, as an emerging practice, limited knowledge is available regarding the detailed interactions with fish immune systems. Therefore, the underlying mechanisms involved in fish immune cell activation need to be explored further. In this context, the present article aspires to review the available studies on the use of bacterial cellular components in fish culture and their biological effects on fish such as growth promotion, immunostimulation and anti‐pathogenic activities as well as to evaluate the factors that control the optimal induction of immune responses in fish. In addition, future issues that merit further investigation are suggested.

Stochastic analysis of production dynamics of male and female redclaw crayfish ( Cherax quadricarinatus ) reared under commercial intensive cultivation - Lavinia Nuñez‐Amao; Humberto Villarreal; José Naranjo‐Paramo; Alfredo Hernandez‐Llamas (Reviews in Aquaculture, 2018)
We used a stochastic model to simulate, over time, total biomass production of male and female Australian redclaw crayfish ( Cherax quadricarinatus ), so as production of commercial‐sized crayfish (40–60 and 61–90 g). The model was calibrated with a database from an intensive commercial farm. Results showed that uncertainty in obtaining production of the 61–90 g grade diminished with time. In the case of 40–60 g grade and total biomass, uncertainty was minimal at 69 days (males 40–60 g grade), 84 days (females 40–60 g grade), 92 days (male total biomass) and 94 days (female total biomass). The model predicted that, at harvesting time, there is 95% confidence intervals that males produce 2.96–3.29 t ha −1 (mean = 3.13 t ha −1 ) and females produce 2.49–2.72 t ha −1 (mean = 2.60 t ha −1 ), of biomass, closely approximating biomass production registered in the database. When increasing sample size from one pond to 16 ponds, variability in production was reduced in 75.5% (males) and 65.2% (females). Sensitivity analysis showed that individual weight, and percentages corresponding to the total commercial population and the 40–60 g size were the variables mostly influencing the variance of yields. The results showed that the dynamics of production of commercial biomass strongly differ among ponds. We conclude that the model is a useful tool for analysis of the stochastic processes governing production dynamics of redclaw crayfish biomass.

Strategies to modulate the intestinal microbiota of Tilapia (Oreochromis sp.) in aquaculture: a review - Alyssa M. Haygood; Rajesh Jha (Reviews in Aquaculture, 2018)
Tilapia ( Oreochromis sp.) are the most widespread aquaculture species grown and are expected to continue increasing in production to meet the growing demand for fish by an ever‐increasing human population. Fish health management is one of the major concerns in the production of aquaculture species. A number of studies have been conducted to identify new procedures for reducing disease of commonly farmed species, such as tilapia. To prevent disease, the use of antibiotics is common practice in most aquaculture facilities. However, consumer demand and increasing incidence of antibiotic resistance have caused the reduction in the use of antibiotics being administered regularly. A recent strategy is the incorporation of antibiotic alternatives, such as probiotics, prebiotics, and alternative carbohydrate ingredients to promote the growth and health of the fish through the modulation of gastrointestinal microbiota. Intestinal autochthonous microbiota fulfils a number of important roles in host digestion, immunity and intestinal integrity. In the past, the majority of studies on the intestinal microbiota of tilapia used culture‐based methods that are not representative of the entire community. With the advancement of molecular techniques, current studies are utilizing culture‐independent methods to monitor the microbial modulation in the tilapia gastrointestinal tract. This review discusses the effects of antibiotics, probiotics, prebiotics and alternative feed ingredients on the intestinal microbiota of tilapia using culture‐independent techniques. Although advances have been made in the understanding of tilapia intestinal microbiota, more research is needed into the microbial ecology, alternative feedstuff effects and economic impacts of modulating intestinal microbiota of tilapia.

Abalone growth and associated aspects: now from a metabolic perspective - Leonie Venter; Du Toit Loots; Andre Vosloo; Peet Jansen van Rensburg; Jeremie Zander Lindeque (Reviews in Aquaculture, 2018)
Worldwide, there are approximately 100 Haliotis species, more commonly known as abalone or ‘Paua’ in New Zealand, ‘Venus's‐ears’ in Greece, ‘Awabi’ in Japan, ‘Perlemoen’ in South Africa and ‘Ormers’ in Europe. Regardless of what they are called in any part of the world, a high monetary value is coupled to this animal, because it is largely considered a seafood delicacy. Subsequently, a great deal of research primarily focused on improving the health and growth rates of abalone were carried out to maximise productivity of the commercial farming efforts in various countries. In this review, we comprehensively describe the most recent available scientific literature on abalone biology, and those aspects related to the growth of this organism; more specifically, those factors related to the uptake and breakdown of metabolic products which ensures long‐term growth. We subsequently discuss this in terms of basic animal design, farming outcomes, feeding, cellular growth mechanisms and the unique metabolic processes that exist in these species. Using this information and the knowledge of the metabolic processes in other organisms, we additionally make a number of new hypotheses regarding how these metabolic processes may function in terms of abalone growth. Based on the information presented in this review, we also identify major research opportunities and gaps in the existing knowledge of abalone metabolism, which when elucidated may not only serve the purpose of better understanding these organisms growth but also could potentially lead to increased productivity of the abalone commercial farming sector.

Design and implementation of a collaborative epidemiological surveillance system for aquaculture (VECA) - Ana Muniesa; Imanol Ruiz‐Zarzuela; Ignacio de Blas (Reviews in Aquaculture, 2018)
Syndromic surveillance and participatory epidemiology are nowadays taking part in the public health system because they can be very interesting tools to complement the classical ones. Although syndromic surveillance could be nonspecific, it is usually based on real‐time data analysis to provide early warnings. Participatory Epidemiology can bring us different and interesting approaches that we can use to better understand the problem. VECA implements an epidemiological surveillance system, validated by experts and users, which allows collecting real‐time information of each facility on production data, origin of animals, environmental parameters, disease status and therapeutic and prophylactic measures. Based on the data collected, the results of preliminary epidemiological analyses have been selected to design the most relevant indexes, which will set different levels of health warning, to help those responsible for aquatic animal health and producers to make the right decisions. The platform can be used by owners or those responsible of farms who wish to collaborate in the development of this system of epidemiological alert and to prevent future diseases that cause incalculable losses in the sector.

Use of formalin in intensive aquaculture: properties, application and effects on fish and water quality - Joana F. Leal; Maria Graça P. M. S. Neves; Eduarda B. H. Santos; Valdemar I. Esteves (Reviews in Aquaculture, 2018)
Formalin (aqueous solution of formaldehyde stabilized with methanol) is one of the most used disinfectants in aquaculture. It is used to eliminate infectious agents but may be responsible for negative effects on fish and water quality. This work focuses on physical–chemical properties of formalin and on its reactions and its use in intensive aquaculture and in environment. The types of treatments and the action mode of formalin are also described. The main consequences of formalin exposure to fish are damage in gills and alterations in mucous cells. Formalin also interacts with some treatments adopted in aquaculture establishments, for example biological filter, where the nitrification process seems to be strongly affected. With respect to formalin inactivation, formaldehyde (effluent) may be diluted with water or specific treatments should be conducted to decrease the concentration levels before its discharge into the environment. The common methodologies applied to aquaculture are not completely efficient on formalin removal from water, and the advanced oxidation processes may be a good alternative.

Occurrence of mycotoxins in commercial aquafeeds in Asia and Europe: a real risk to aquaculture? - Rui A. Gonçalves; Karin Naehrer; Gonçalo A. Santos (Reviews in Aquaculture, 2018)
There is increasing awareness of the negative effects of mycotoxins in aquatic species, which is highlighted in recent publications. Partly due to climate change associated with an overall increase of mycotoxins contamination in plant ingredients, and also due to the tendency to replace expensive animal‐derived proteins, such as fish meal, by more economical plant proteins sources, which increases the probability of mycotoxin contamination in aquaculture feeds (Hooft et al . ). Over a 1‐year period, 41 samples of finished aquaculture feed, both shrimp and fish, were analysed within the scope of BIOMIN mycotoxin survey programme. The samples were tested for aflatoxins, zearalenone, deoxynivalenol, fumonisins and ochratoxin A. Samples were sourced in Asia (31 samples) and Europe (10 samples) from fish/shrimp farms or feed producers. The values detected pose a risk for several important aquaculture species, assuming single mycotoxin contamination, that is excluding possible additive and synergetic effects between mycotoxins. Co‐occurrence of mycotoxins in feeds may induce synergistic effects and increase the negative impact of mycotoxins in aquatic‐farmed species at lower levels than when present in single contamination. This review gives an overview of the different mycotoxins and revises the effects of mycotoxins in aquatic species. Additionally, it reports the levels of mycotoxins in aquafeeds in 2014 and compares detected levels with possible negative effects in fish and shrimp. As it is highlighted by the results of the survey, the risk of co‐occurrence is high and the knowledge on the effects of multimycotoxins contamination in aquatic species is basically none.

South American fish for continental aquaculture - Gustavo Moraes Ramos Valladão; Sílvia Umeda Gallani; Fabiana Pilarski (Reviews in Aquaculture, 2018)
The South American continent is known for its high production and exports in fisheries and aquaculture, but has not reached its full potential in fish farming. The latest data on fish production in Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Uruguay and Venezuela were explored in this review. Aspects of biology, production, market and health of the species most produced in South America are described in detail. These species include the round fish ( Colossoma spp., Piaractus spp. and hybrids) and catfish ( Pseudoplatystoma spp. and hybrids), in addition to the promising pirarucu Arapaima gigas , yellowtail tetra Astyanax altiparanae and silver catfish Rhamdia quelen . Among the countries mentioned, Chile and Brazil are two of the largest intensive fish producers in the world. Chile relies primarily on marine fish, whereas Brazil is prominent for continental production. Special emphasis is given to the black pacu Colossoma macropomum because it is a commonly farmed fish in South American countries and offers several desirable productive characteristics (domesticated, omnivorous and easy to reproduce). Furthermore, this fish has the greatest potential to compete economically with tilapia production in South America. The production of native fish is currently overtaking the production of exotic species in some countries, which is considered a milestone for South American aquaculture. Regarding diseases, the main pathogens are similar to those observed throughout the world, such as Ichthyophthirius multifiliis , different species of monogeneans and trichodinids, and the bacteria Aeromonas hydrophila . Local pathogens, such as the parasites Perulernaea gamitanae and Goezia spinulosa , are also concerning.

Innate and adaptive immune molecules of striped murrel Channa striatus - Rajesh Palanisamy; Prasanth Bhatt; Venkatesh Kumaresan; Mukesh Pasupuleti; Jesu Arockiaraj (Reviews in Aquaculture, 2018)
Channa striatus, also called snakehead murrel, is an important freshwater teleost fish which has been widely cultured for its tasty flesh along with nutritional and medicinal values. The growth of both cultured and wild murrels is affected by various physical, chemical and biological factors. As a teleost fish, C. striatus is an intermediate organism between invertebrates and vertebrates. They have a well‐developed innate immune system than invertebrates and a primitive adaptive immune system compared to that of higher vertebrates, thus an interesting unique immune structure to explore. Studies have identified that a few external stimulants do instigate the immune system to fight against the pathogens at the time of infection in C. striatus . This review discusses the physicochemical and biological stress factors, immune system and immune molecules of C. striatus which are potentially involved in combating the stress factors.

Aquaculture of marine non‐food organisms: what, why and how? - Miguel Costa Leal; Rui Jorge Miranda Rocha; Rui Rosa; Ricardo Calado (Reviews in Aquaculture, 2018)
Aquaculture is among the fastest growing industries in the world and the fastest in the food production sector. However, not all aquaculture organisms are produced for human consumption. Indeed, an important fraction of aquaculture products target a wide variety of applications, from pharmaceutical, cosmeceutical, ornamental and nutraceutical applications, as well as biofuel production, conservation efforts and academic purposes, among others. Despite the increasing importance of aquaculture for non‐food purposes, a comprehensive review covering the state of the art of this topic, its latest developments and future trends is missing. Here, we review what marine organisms are produced for non‐food purposes, as well as why and how they are produced. Instead of providing a thorough methodological review, production protocols are briefly summarized and an updated guide to the most relevant literature is provided. We overview current developments driving the aquaculture of non‐food organisms, underpin their most significant applications and highlight future prospects for non‐food aquaculture.

Natural antioxidants from sea: a potential industrial perspective in aquafeed formulation - Mohammad Aklakur (Reviews in Aquaculture, 2018)
Aquaculture is set to grow amidst threats of new stressors and diseases. The increasing awareness on nutrition and feeding has led a paradigm shift towards therapeutic nutrition, an alternative aquaculture management strategy that can create a balance between productivity and long‐term sustainability. The core objective behind this approach was to minimize the impact of stressors via neutralization of free radicals, repair of oxidative damage to biomolecules and membrane systems, immune augmentation and maintenance of normal physiological homoeostasis. The eventual shift of balance between oxidants and antioxidants leads to oxidative stress and subsequently immune suppression, pathological symptoms and slow growth. Therefore, in aquaculture the use of supplemental antioxidants and augmentation of endogenous cellular antioxidants becomes essential. Lipid rancidity is the major concern, which determines feed stability and storage time, besides the cellular antioxidant homoeostasis. As observed, ethoxyquin ( EQ ), the widely used synthetic antioxidant in animal feed industry, has growing human health hazard concerns. Efficient and cost‐effective natural antioxidants are a real need of time. The most diverse marine ecosystem opens a new horizon for extraction and development of natural antioxidants from sea. The antioxidants such as vitamin E, vitamin C, peptides, amino acids, chitooligosaccharide derivatives ( COS ), astaxanthin, carotenoids, sulphated polysaccharides ( SP s), phlorotannins, phenolic compound and flavones had shown a great potential to be used in feed formulation, as an additive for feed quality maintenance and shelf life. Therefore, new industrial perspectives and novel approaches are required for isolation and development of bioactive substances with antioxidative property for cost‐effective feed.

Genetic connectivity among populations of two congeneric direct‐developing whelks varies across spatial scales - Angela M. Fleming; Melanie M. Dohner; Nicole E. Phillips; Peter A. Ritchie (New Zealand Journal of Marine and Freshwater Research, 2018)
We examined the phylogeographic structure of two congeneric, direct‐developing, intertidal whelks endemic to New Zealand, Cominella virgata and C. maculosa . A total of 855 specimens were collected from 23 rocky shore locations and we used them to determine the level of DNA sequence variation at the mitochondrial DNA (mtDNA) cytochrome c oxidase subunit I gene. Cominella virgata and C. maculosa have relatively high levels of haplotype diversity but low levels of nucleotide diversity. Sample sites formed regional groups that were composed of genetically differentiated populations, a finding consistent with their limited dispersal abilities. Cominella virgata showed higher levels of regional differentiation than C. maculosa , and there were also species‐specific differences in genetic patterns within some regions. Both species exhibited genetic homogenisation among proximate sites within groups, suggesting some dispersal does occur between areas that are not connected by contiguous rocky shore habitat.

Factors influencing biodeposit production by the New Zealand freshwater mussel Echyridella menziesii - Kevin J. Collier; Susan J. Clearwater; Paula H. M. W. Neijenhuis; Susanna A. Wood (New Zealand Journal of Marine and Freshwater Research, 2018)
Laboratory experiments on the New Zealand freshwater mussel Echyridella menziesii were used to investigate the short‐term effects (7–8 days) of food type on rates of biodeposition and benthic substrate respiration. Post‐feeding biodeposition rates ranged from 0.34 to 1.52 mg g −1 h −1 (mean = 0.50 mg g −1 h −1 ) and were unaffected by the addition of toxin‐producing Microcystis . Addition of suspended sediment (30 mg L −1 ) visibly altered substrate composition, and increased total and inorganic biodeposit production rates by 24–33% compared to mussels fed commercial phytoplankton stock. Biodeposition rates of mussels in lake bed substrates were 38% higher than those in silica sand for identical feeding regimes, suggesting that a significant proportion of material produced in this experiment could have been derived from feeding on organic matter in the lake bed sediments. Respiration rates were higher in treatments with Microcystis but were unaffected by the presence of mussels. This laboratory study suggests that biodeposition by E. menziesii is resilient to short‐term exposure to Microcystis , and highlights the ability of mussels to alter benthic substrate composition by incorporating suspended sediment into substrates.

Rotenone treatment has a short‐term effect on New Zealand stream macroinvertebrate communities - Lan Pham; Matt G. Jarvis; David West; Gerard P. Closs (New Zealand Journal of Marine and Freshwater Research, 2018)
Invasive fish eradication is a key management strategy in aquatic ecosystems, and is often accomplished using piscicides such as rotenone. However, the effects of piscicides on aquatic invertebrate communities are poorly understood, particularly over long time scales. We monitored invertebrate communities in two treatment and two reference streams prior to and for one year following the use of rotenone to eradicate trout in Zealandia wildlife sanctuary, Wellington. Immediately following treatment, invertebrate density and taxonomic richness declined significantly, and community composition diverged markedly relative to reference streams, with pollution sensitive taxa declining greater than more tolerant taxa. Treatment streams recovered to pre‐treatment conditions within 4–12 months of rotenone application, indicating minor long‐term impacts on invertebrate communities. Speed of recovery of individual taxa appeared to be associated with life history variables, e.g. generation times and dispersal ability. Untreated upstream reaches and nearby water bodies likely facilitated successful invertebrate community recovery. Our results demonstrate that rapid recovery of New Zealand stream invertebrate communities is possible within one year of rotenone application.

Establishing habitat‐specific indicator species in Tierra del Fuego with freshwater macroinvertebrates - Christopher B. Anderson; Montana Johnson; María Eugenia Lopez (New Zealand Journal of Marine and Freshwater Research, 2018)
As a tool to understand Tierra del Fuego’s basic ecology and detect changes due to human pressures, this study develops habitat bioindicators. We compared the freshwater benthic macroinvertebrates at 61 study sites in six habitat types: grassland streams, urbanised streams, forested streams, beaver ponds, lakes and peat bog ponds. Forty‐nine taxa were identified; insects were the most diverse group. Beaver pond, lake and grassland stream assemblages were similar, as were those from lakes, grassland streams and peat bog ponds. Fourteen taxa were habitat‐specific. In forests, these included mayfly scrapers ( Andesiops , Meridialaris ) and blackfly filterers ( Gigantodax ). In lakes, two copepod filterers were indicators, and in urban streams, one shredder ( Aphroteniella ) and three collector‐gatherers (springtail, earthworm, aquatic worm). Predators ( Corixa , Aeshna ) were characteristic of peat bog ponds. Beaver ponds had no indicator species. Establishing links between species and ecosystems constitutes the beginning of a broader effort to understand anthropogenic impacts to Fuegian watersheds.

Reproductive biology of the leatherjacket, Meuschenia scaber (Monacanthidae) (Forster 1801) in the Hauraki Gulf, New Zealand - Valerio Visconti; Elizabeth D. L. Trip; Marc H. Griffiths; Kendall D. Clements (New Zealand Journal of Marine and Freshwater Research, 2018)
The leatherjacket Meuschenia scaber is widely distributed in Australasian waters, and is a valued bycatch of inshore bottom trawl fisheries although little is known of its life history. Here, we describe the reproductive biology of the species based on 651 leatherjackets sampled in the Hauraki Gulf, New Zealand, between July 2014 and March 2016. The maximum total length ( L T ) recorded for females and males were 320 and 315 mm, respectively, with both sexes present in all size classes. Monthly analysis of gonad condition revealed a clear spawning season from late austral winter to early summer (August–December), and histological analysis of the ovaries revealed that M. scaber is an indeterminate serial spawning gonochorist. The estimated sizes at sexual maturity ( L 50 ) for females (189.9 mm L T ) and males (188.4 mm L T ) did not differ significantly. Relatively small testes, sexual dimorphism and underwater observation of nesting suggest that M. scaber is a paired spawner.

The spawning and early life‐history of a New Zealand endemic amphidromous eleotrid, bluegill bully ( Gobiomorphus hubbsi ) - Matt G. Jarvis; Hannah A. Harland; Manna L. Warburton; Gerard P. Closs (New Zealand Journal of Marine and Freshwater Research, 2018)
The larval stage of fishes is critical in determining their dispersal, survival and recruitment, but little is known of the larval behaviours and tolerances of amphidromous fishes, particularly in New Zealand. We report the results of a series of observational and experimental studies on bluegill bully ( Gobiomorphus hubbsi ), including spawning sites and behaviours, larval characteristics at hatch, phototactic responses of larvae, and larval survival at different salinity levels. Spawning primarily occurred in the lower reaches of the river, and larvae from different nests exhibited marked differences in, and trade‐offs between, larval characteristics at hatch, potentially affecting larval success. Larvae were positively phototactic to intense light, an unexpected result based on diel drift patterns and international research. Finally, larvae exhibited markedly higher survival rates when reared at intermediate salinities compared to freshwater or seawater, suggesting estuaries may play an important role as nursery grounds for bluegill bully and other amphidromous fish.

First capture and description of larval torrentfish ( Cheimarrichthys fosteri ) during their seaward migration - Matt G. Jarvis; Manna L. Warburton; Aurélien Vivancos; Gerard P. Closs (New Zealand Journal of Marine and Freshwater Research, 2018)
While many of New Zealand’s freshwater fishes undertake larval migrations as part of their amphidromous life‐history, little is known of the larval stages of these fish. Torrentfish ( Cheimarrchthys fosteri ), a New Zealand endemic, amphidromous, riffle specialist are particularly enigmatic; their spawning sites and behaviours are unknown, and larvae have never been collected either emigrating from freshwater or during their marine feeding phase. During summer drift sampling, we captured unidentified fish larvae emigrating downstream in the Waianakarua River, South Island, New Zealand. Based on multiple lines of evidence (meristic comparisons with adults, morphology, time of capture, and adult fish populations of the Waianakarua) we identify these larvae as torrentfish. This represents the first time torrentfish larvae have been captured or identified, laying the foundations for future studies into the early life‐history and ecology of this unique and threatened fish.

Corrigendum (New Zealand Journal of Marine and Freshwater Research, 2018)

Phylogeographic patterns in Maguimithrax spinosissimus (Decapoda: Mithracidae) from Colombian Caribbean - Julio César Hurtado‐Alarcón; Néstor Hernando Campos Campos; Adriana Bermúdez Tobón; Edna J. Márquez (New Zealand Journal of Marine and Freshwater Research, 2018)
The Caribbean king crab Maguimithrax spinosissimus is an important artisanal fisheries resource with a distribution range that includes the Florida Keys and Caribbean Sea islands. We carried out a phylogeographic analysis of M. spinosissimus in one oceanic (Old Providence) and two continental islands (Rosario and Tintipán). We analysed 89 and 49 Control Region (CR) and Cytochrome Oxidase I (COI) sequences, respectively. We found genetic differentiation between Old Providence and Rosario + Tintipán units ( F ST values of 0.84 for CR and 0.91 for COI gene), and gene flow between Rosario and Tintipán ( F ST values −0.0085 for CR, P > .88; −0.01 for COI gene, P > .99). Our analysis showed two genetic stocks and possibly an isolated biogeographic unit of M. spinosissimus . We suggest managing the species as different populations, and conducting more ecological and biological studies for the determination of possible cryptic species.

Short‐term and diurnal temperature changes alter the response of harmful algal blooms of Pseudo‐nitzschia pungens to solar ultraviolet radiation - J. Chen; H. Wang; A. Q. Yang; R. R. Si; W. C. Guan (New Zealand Journal of Marine and Freshwater Research, 2018)
In this study, we explored the interactive effects of temperature and solar ultraviolet radiation (UVR) on the growth, pigment contents, photochemical efficiency and non‐photochemical quenching (NPQ) of Pseudo‐nitzschia pungens , which forms harmful algal blooms globally. Cells were first pre‐acclimated to temperatures of 20°C, 25°C or 28°C for 10 days. They were then exposed to three different types of solar radiation for 60 min. We then measured the photochemical efficiency of the cells during the 60‐min exposure and a 360‐min recovery period under dim light (20 μmol photons m − 2 s −1 ). In addition, we analysed the diural change in photochemical efficiency and NPQ over a 10‐h period. We found that P. pungens that were exposed to higher temperatures in the short term (i.e. 20–25°C, 20–28°C and 25–28°C) or long term (i.e. 25–25°C and 28–28°C) exhibited lower levels of photoinhibition and faster recovery rates than samples exposed to a lower temperature (i.e. 20–20°C). This indicated that the deleterious effects of UVR can be minimised by both chronic and acute exposure to higher temperatures within the tolerated temperature range for P. pungens .

The effect of willow control using a glyphosate formulation on aquatic invertebrates within a New Zealand wetland - Janine Wech; Alastair Suren; Matthew Brady; Cathy Kilroy (New Zealand Journal of Marine and Freshwater Research, 2018)
Exotic trees, such as willow ( Salix spp.), have become invasive around New Zealand waterways. Lowland wetlands in particular are vulnerable, with invasions changing hydrology and causing biodiversity loss. Applying herbicide to the willow canopy is a cost‐effective control method, however uncertainty remains around effects on wetland aquatic invertebrates. Within a North Island, New Zealand, wetland, we conducted a paired before‐after, control‐impact study to determine if aerially applied glyphosate (with adjuvants) affected invertebrate assemblages. No effect on communities was detected during the first year after glyphosate treatment, however significant differences between control and spray‐exposed communities were found during the second year, coinciding with a significant drought event in March 2013. By the third year, no statistically significant differences were found between communities from control and spray‐exposed sites. This study suggests that glyphosate use, in comparable environments, is unlikely to affect aquatic invertebrates. Furthermore, the study illustrates invertebrate communities’ resilience to drought events.

Chinese Abstracts (Reviews in Aquaculture, 2018)

Issue Information (Reviews in Aquaculture, 2018)

Metabolomic strategies for aquaculture research: a primer - Tim Young; Andrea C. Alfaro (Reviews in Aquaculture, 2018)
Metabolomics is a fast‐evolving field that provides qualitative and quantitative analyses of metabolites within cells, tissues or biofluids. Recent applications of metabolomics approaches in aquaculture research have highlighted the huge potential for solving problems within all aspects of the production line, from hatchery production to post‐harvest quality control. To assist with the growing application of metabolomics in aquaculture research, this contribution provides a review of techniques and steps necessary to conduct metabolomics research, from experimental design to data interpretation. Specifically, we target scientists who are new to the field of metabolomics, and we offer simple, but comprehensive steps and strategies to conduct this type of research. We conclude this primer with some advice on how to access relevant expertise and facilities for metabolomics‐based aquaculture research.

Meta‐analysis approach to the effects of live prey on the growth of Octopus vulgaris paralarvae under culture conditions - Diego Garrido; M. Virginia Martín; Covadonga Rodríguez; José Iglesias; Juan C. Navarro; Alicia Estévez; Francisco Hontoria; Mikel Becerro; Juan J. Otero; Josu Pérez; Inmaculada Varó; Diana B. Reis; et al. (Reviews in Aquaculture, 2018)
The common octopus ( Octopus vulgaris , Cuvier 1797) is a promising species for aquaculture diversification, but the massive mortality during the first life stage is the main bottleneck for its commercial production. The aim of the present study was to compare the effects of different live preys ( Artemia and crustacean zoeae) and/or Artemia enrichment protocols in the paralarval growth by using a meta‐analysis approach. A total of 26 independent assays were used, including data from the bibliography and from experiments carried out by our group. Three comparisons were established: (i) crustacean zoeae vs. Artemia , (ii) different crustacean zoeae species and (iii) Artemia enriched with marine lecithin (rich in polar lipids‐ PL and docosahexaenoic acid‐ DHA ) vs. previously used Artemia enrichments. The meta‐analysis approach allowed a quantitative review of independent studies with reliable conclusions, avoiding the subjectivity inherent to classical reviews. The outputs provided statistical confirmation of the better suitability of crustacean zoeae with respect to Artemia . However, not all crustacean species showed the same results, given that the high variability on Grapsus zoeae hampered finding significant differences with respect to the control treatment ( Artemia ). Nutrient composition and biometry of the different types of prey are discussed as possible causes of the differences arising from the meta‐analysis. Finally, the present results suggest that marine lecithin has a beneficial effect on paralarval growth with respect to previously used enrichments, which could be related to the increase in DHA and PL in Artemia , given the essential role of these lipid components in octopus paralarval physiology.

Role of deposit‐feeding sea cucumbers in integrated multitrophic aquaculture: progress, problems, potential and future challenges - Leonardo Nicolas Zamora; Xiutang Yuan; Alexander Guy Carton; Matthew James Slater (Reviews in Aquaculture, 2018)
There is significant commercial and research interest in the application of sea cucumbers as nutrient recyclers and processors of particulate waste in polyculture or integrated multitrophic aquaculture ( IMTA ) systems. The following article reviews examples of existing IMTA systems operating with sea cucumbers, and details the role and effect of several sea cucumber species in experimental and pilot IMTA systems worldwide. Historical observations and quantification of impacts of sea cucumber deposit‐feeding and locomotion are examined, as is the development and testing of concepts for the application of sea cucumbers in sediment remediation and site recovery. The extension of applied IMTA systems is reported, from basic piloting through to economically viable farming systems operating at commercial scales. The near‐global recognition of the ecological and economic value of deposit‐feeding sea cucumbers in IMTA applications within existing and developing aquaculture industries is discussed. Predictions and recommendations are offered for optimal development of sea cucumber IMTA globally. Future directions within the industry are indicated, and key areas of ecological, biological and commercial concern are highlighted to be kept in mind and addressed in a precautionary manner as the industry develops.

Perceived versus real toxicological safety of pangasius catfish: a review modifying market perspectives - Albertinka J. Murk; Ivonne M.C.M. Rietjens; Simon R. Bush (Reviews in Aquaculture, 2018)
Mass media reports suggest that pangasius ( Pangasianodon hypophthalmus ) is ‘full of poison’ because it is able to survive in the ‘heavily polluted Mekong River’ and contains pesticides and veterinary treatment chemicals. However, most of these claims are not substantiated with scientific evidence. To assess the safety of pangasius consumption, a full toxicological risk assessment was performed. The results obtained were compared to toxicity claims made in a selection of media reports. Information on contaminant levels encountered in pangasius was collected from the EU Rapid Alert System for Food and Feed ( RASFF ) database. The toxicological risk assessments do not support any of the toxicological risks suggested in the media. Next, the maximum pangasius consumption that would be considered safe was estimated on the basis of the highest levels of the toxic contaminants reported in Vietnamese pangasius by RASFF and the safety thresholds for the contaminants. The maximum amount of the recalled fillet that could have been consumed without any adverse effects amounted to between 3.4 and 166.7 kg day −1 (lifelong for a 70 kg adult) in the case of pesticide contamination and between 0.613 and 303 kg fillet day −1 in the case of preservatives and antibiotics. It is concluded that consumption of pangasius available on the European market does not pose any concern for the health of the consumer. The analysis presented in this study illustrates that publicly available independent information could help consumers to develop their own well‐informed opinion about food safety issues.

Breeding and culture status of Hilsa ( Tenualosa ilisha, Ham. 1822) in South Asia: a review - Amiya Kumar Sahoo; Md. Abdul Wahab; Michael Phillips; Anisur Rahman; Arun Padiyar; Velmurugu Puvanendran; Rama Bangera; Ben Belton; Dilip Kumar De; Dharmendra Kumar Meena; Bijay Kumar Behera; Anil Prakash Sharma; et al. (Reviews in Aquaculture, 2018)
The Hilsa shad, Tenualosa ilisha popularly known as ‘Hilsa’, is one of the most commercially important fish species in South Asian countries. The species is widely distributed from the Persian Gulf to Bay of Bengal and ascends into estuaries, rivers and brackish‐water lagoons of the Indo‐Pacific region. Recently, the availability of hilsa has drastically dwindled in aquatic systems across this region, due to anthropogenic pressures, mainly intensive fishing and river obstruction by dams and barrages. Climate change may also be contributing to the declining populations. Hence, there is an urgent need for conservation of the species. In addition, hilsa is of great cultural and economic importance among the peoples of Ganga‐Brahmaputra‐Meghna basin, with very high market demand and increasingly high prices, presently an average of around US$ 12 per kg for consumers both in India and Bangladesh. Many attempts at hilsa breeding and culture have been made across South Asia, particularly in India and Bangladesh, since the 1900s. To date, no breakthrough has been achieved in completing the life cycle in captivity. This review provides an insight into the status of artificial breeding, larval rearing and culture of this species, and identifies research gaps that need to be addressed by future aquaculture development programmes for hilsa in South Asia.

Bacteria as food in aquaculture: do they make a difference? - Nancy Nevejan; Peter De Schryver; Mathieu Wille; Kristof Dierckens; Kartik Baruah; Gilbert Van Stappen (Reviews in Aquaculture, 2018)
Bacterioplankton is an important component of marine as well as fresh waters and accounts for a large fraction of the production of particulate matter in those ecosystems. The concept of bacteria as providers of essential nutrients in aquatic food webs has been raised most recently in relation to the utilization of bacteria as a food source in aquaculture food chains. This article represents a comprehensive review on the potential role of bacteria as a direct food source for aquaculture organisms. After studying shortly the analytical tools that can be applied to determine the uptake and assimilation of bacteria by higher trophic levels, it describes the bacterial loads that are found in closed and open aquaculture systems and elaborates on the composition of bacteria from a nutritional point of view. Next this study elaborates in more detail on the role of bacteria as food for the zooplankton groups used as live food in aquaculture hatcheries and for various groups of aquaculture target organisms, such as fish, crustaceans and especially bivalves. This includes an assessment of the specific uptake mechanisms of the different taxonomic groups of interest in relation to their efficiency to ingest bacteria. Finally, future research lines are suggested to elucidate the nutritional impact of the bacterial community in aquaculture systems and how to steer this in order to optimize the production.

Showcasing metabolomic applications in aquaculture: a review - Andrea C. Alfaro; Tim Young (Reviews in Aquaculture, 2018)
Aquaculture production is currently challenged to meet the growing demands for seafood protein throughout the world. To achieve this growth in an efficient, safe and sustainable manner, novel tools and applications will need to be incorporated at each step of the production line. A variety of ‘omics’ (e.g. transcriptomics, proteomics, metabolomics) applications have already begun to emerge in aquaculture research with extreme success. A promising new ‘omics’ approach is metabolomics, which aims to use metabolite profiles to identify biomarkers indicative of physiological responses of living samples (e.g. whole organism, tissues, cells) to environmental or culture conditions. One of the benefits of this approach is that it uses a broad scan of biological conditions to identify often unexpected problem or risk areas upon which to focus management attention. In this contribution, we have selected relevant research examples to showcase the applications of metabolomics in aquaculture in four major areas: hatchery production, nutrition and diet, disease and immunology, and post‐harvest quality control. The novelty of this approach is highlighted by the fact that we cite the majority of published papers in this field, and they are all recent (within the last decade) contributions.

Cryopreservation and vitrification of fish semen: a review with special emphasis on marine species - Caio Magnotti; Vinicius Cerqueira; Manuel Lee‐Estevez; Jorge G. Farias; Iván Valdebenito; Elías Figueroa (Reviews in Aquaculture, 2018)
Semen conservation methods have been extensively studied for fish species over the last 60 years. Cryopreservation techniques can be divided into two types: one with slow cooling rates like traditional freezing and the other with ultrarapid rates as used in vitrification. These protocols increase the time over which semen samples can be used for reproduction or sperm quality analysis. Marine fish possess greater resistance than freshwater species to variations in osmolality. This favours the application of these methods, which produce better results after thawing and offer high biotechnological potential for aquaculture. In the last 15 years, sperm cryopreservation studies have been carried out in 32 marine species, but there are few analyses of the effects of freezing on the morphology and physiology of sperm cells. The object of this review was to provide recent data on semen cryopreservation in marine fish species and to suggest variables which may be applied in future research.

Expansion of aquaculture parks and the increasing risk of non‐native species invasions in Brazil - Luciano B. Lima; Fagner Junior M. Oliveira; Henrique C. Giacomini; Dilermando P. Lima‐Junior (Reviews in Aquaculture, 2018)
Aquaculture is the main vector for introduction of non‐native species in Brazil and around the world. Despite the potentially serious and irreversible ecological impacts caused by non‐native species, they continue to be in many cases the preferred option in aquaculture farms, of which the recent plans of aquaculture expansion promoted by the Brazilian Government are an emblematic example. In this study, we present a survey of publicly available information on aquaculture parks to be installed across the Brazilian territory, with emphasis on species status as native or non‐native, and discuss the implications for the conservation of aquatic biodiversity. One hundred and thirty‐nine aquaculture parks ( AP s), with a total of 1556 sites covering 941.38 hectares, have been called for bids. Among these, 122 AP s will contain at least one non‐native species, and 68 AP s will be based exclusively on their cultivation. A predictable consequence is the enhancement of propagule pressure in surrounding aquatic ecosystems, increasing the risk of non‐native species establishment or persistence, which will likely intensify the environmental impacts already in course in four major river basins and along the Brazilian coast. These impacts will add up to more direct effects of aquaculture farming – for example elevated input of nutrients and organic matter – and include changes in habitat and water quality, spread of diseases, biotic homogenization, loss of population viability resulting from hybridization and outbreeding depression, and the local extirpation of native species.

Zebrafish as a useful model for immunological research with potential applications in aquaculture - Manuel Lee‐Estevez; Elías Figueroa; Jacky Cosson; Stefanía E. Short; Ivan Valdebenito; Patricio Ulloa‐Rodríguez; Jorge G. Farías (Reviews in Aquaculture, 2018)
The Zebrafish ( Danio Rerio ) is a Teleost fish, which offers several practical advantages concerning manipulation, maintenance and versatility as well as short life cycle, low cost and physiological similarity with most farmed species. Zebrafish have been used as model for several aquaculture‐relevant infectious agents, since the cost of infections to aquaculture can be great, making failure of immunity a major risk for commercial fish farming. This have allowed scientist to understand pathogens biology as well as fish immune response against infection, and thus have helped to improve disease control in aquaculture. This review summarizes the recent reports and main knowledge concerning the cellular and molecular aspects of the immune response in zebrafish and its potential applications in the fish farming industry. Several research results in zebrafish and other teleosts reveal that mucosal tissues have a strong and well‐structured immune response involving both innate and adaptive components. Together with the advantages of low maintenance cost, easy handling and genetic tools available, zebrafish comes up as a useful and reliable animal model for in vivo study of fish immune response and mechanisms as well as fish‐affecting infectious and inflammatory diseases which are a cause of concern for the aquaculture industry. Also, vaccines development, drugs screening and immunologically focused fish food assessment seem to be promising fields where zebrafish model can be used to generate positive impacts to the aquaculture practice.

Potential of microbial‐derived nutrients for aquaculture development - Julián Gamboa‐Delgado; Julia Mariana Márquez‐Reyes (Reviews in Aquaculture, 2018)
Fisheries and aquaculture products will have a lead role in satisfying the food requirements of the growing human population. The fish meal required for the manufacture of aquaculture feeds represents a limited resource having high demand. Unconventional sources of nutrients have been intensely researched and among these, the microbial biomass produced from heterotrophic and autotrophic microorganisms has been considered as a promising substitute for animal‐ and plant‐derived ingredients. Several studies have shown that different species of yeast, bacteria and microalgae are viable for high density culture and show excellent nutritional characteristics for terrestrial and aquatic animals. Such features have lead to additional research to upscale production and although production costs are still high; novel, sophisticated methods have focused on utilizing alternative substrates for producing microbial biomass. The aquaculture industry requires renewable nutrient sources that can yield high quality protein and other essential nutrients. In this context, the nutritional characteristics of microorganisms and the emerging technologies aimed to produce microbial biomass allow forecasting increased applications. The present manuscript reviews the current state of the production and use of microorganisms as dietary ingredients in aquaculture nutrition, with emphasis on those showing solid potential as functional additives and fish meal replacement ingredients. A synthesis of recent results on the effects promoted by the dietary inclusion of microbial biomass is presented, underlining the employment of different sources of yeast, bacteria and microalgae and the physiological ability of aquatic animals to utilize these alternative nutrient sources.

Application of zeolites in aquaculture industry: a review - Zahra Ghasemi; Iman Sourinejad; Hossein Kazemian; Sohrab Rohani (Reviews in Aquaculture, 2018)
Zeolites are microporous crystalline hydrated aluminosilicates, which have found various applications because of their very unique physicochemical characteristics such as ion exchange and adsorption–desorption properties. Significant progress has been made in recent years on applications of these inorganic adsorbents in different industries including agriculture, aquaculture, water and wastewater treatment, air purification and petrochemicals. This review article intends to summarize the published reports on the applications of natural, synthetic and modified zeolites in aquaculture industry. Application of zeolitic materials for water quality improvement of fish farms and fish transportation tanks by selective capturing of ammonia and toxic heavy metals and zeolite application as feed additive to enhance fish growth and promote their health and nutritional parameters are the most important discussed areas. According to the technical data that are discussed in this review, natural and synthetic zeolites should be considered as materials with tremendous potential of applications in the aquaculture industry. Considerable amounts of research works are under way to explore other opportunities for application of zeolites to benefit aquaculture industry.

Selection response in fish and shellfish: a review - Trygve Gjedrem; Morten Rye (Reviews in Aquaculture, 2018)
The aquaculture sector is significantly behind plant and farm animal production in applying selective breeding, in spite of the fact that it has been suggested that the world aquaculture production could be doubled in 13 years if breeding programmes were supplying stocks for the farmed species. It is estimated that as late as in 2010, only 8.2% of the world's total aquaculture production was based on material developed in selective breeding programmes. Reported estimates of genetic gain per generation for a key trait like growth rate average 13%, implying that the animal's potential for growth can be doubled in a time span of only six generations of selection, as demonstrated for major farmed species like Atlantic salmon and Nile tilapia. Likewise are reported genetic gains for improved disease resistance generally very high. This study offers an updated review of published estimates on genetic gains for a range of traits in aquaculture species. Results are highly encouraging and demonstrate a substantial potential for genetic improvement in aquatic productions, in particular for traits such as growth rate and resistance to diseases.

Recapturing escaped fish from marine aquaculture is largely unsuccessful: alternatives to reduce the number of escapees in the wild - Tim Dempster; Pablo Arechavala‐Lopez; Luke T. Barrett; Ian A. Fleming; Pablo Sanchez‐Jerez; Ingebrigt Uglem (Reviews in Aquaculture, 2018)
Farmed fish that escape and mix with wild fish populations can have significant ecological and genetic consequences. To reduce the number of escaped fish in the wild, recapture is often attempted. Here, we review the behaviours of escapees post‐escape, and how recapture success varies with escaped fish size, the size of the initial escape event and recapture methods. Success rates of fishing gears varied among species, with gill‐nets and coastal barrier nets most effective for recapture of salmonids. Recapture success was strongly negatively correlated with both fish size and the number of fish escaped, regardless of species. Recapture success was universally low across all studied species (8%). Numerous tracking studies of escaped fish indicate that recapture efforts should be initiated within 24 h of an escape incident for highest recapture success. However, most large escape events are due to storms, which mean recapture efforts rarely start within this timeframe. Recapture of escaped fish is broadly ineffective in marine habitats, with rare exception. High bycatch rates during ineffective recapture attempts imply that large‐scale recapture efforts should be weighed against the possibility of affecting wild fish populations negatively. We suggest three alternative approaches to reduce escapee numbers in wild habitats: (i) protect populations of predatory fish around sea‐cage farms from fishing, as they prey upon smaller escapees; (ii) construct impact offset programmes to target recapture in habitats where escapees can be efficiently caught; and (iii) ensure technical standards are legislated so that fish farmers invest in preventative technologies to minimize escapes.

Aquaculture of Sarcothalia atropurpurea tetraspores in New Zealand for carrageenan production - S. E. McNeill; R. Falshaw (New Zealand Journal of Marine and Freshwater Research, 2017)
The endemic red seaweed Sarcothalia atropurpurea is a potentially valuable source of carrageenan, but no information is available on growing this species as a crop in New Zealand. Tetraspores released from wild‐harvested reproductive thalli were settled onto strings and grown initially in tanks under two different day‐lengths. Seeded strings were transplanted to open water at 2, 6 and 10 weeks after spore release. Gametophytic biomass was harvested twice by pruning plants approximately six and nine months after spore release. Sporeling length was correlated with day length during tank culture but these differences were not apparent after a period of open‐water culture. Spores cultured with medium day‐length for 6–10 weeks before transfer to open water grew into harvestable plants that contained similar amounts and types of carrageenan to that from wild material. These results demonstrate for the first time that aquaculture of gametophytic S. atropurpurea from tetraspores is possible.

Editorial Board (New Zealand Journal of Marine and Freshwater Research, 2017)

Epiphytic diatoms as indicators of ecological condition in New Zealand’s lowland wetlands - C. Kilroy; A. M. Suren; J. A. Wech; P. Lambert; B. K. Sorrell (New Zealand Journal of Marine and Freshwater Research, 2017)
The condition of New Zealand’s remnant wetlands has been documented by landscape‐scale assessments such as the Index of Ecological Integrity and Wetland Condition Index. We explored the potential for microscopic aquatic biota (epiphytic diatoms) to provide complementary information about wetland condition using data from 77 lowland sites (mainly palustrine swamps) with circumneutral pH. In the South Island, correspondence between diatoms and wetland indices or water quality was weak. In the North Island, conductivity and total dissolved nitrogen (TDN) together explained 49% of the variance in assemblage composition and several diatom genera were indicative of high or low conductivity, dissolved phosphorus and TDN. Changes in these water quality variables may trigger changes in wetland condition, which are eventually reflected by the landscape‐scale indices. Diatoms respond rapidly to water quality changes suggesting potential for diatom indicator taxa to provide early warning of wetland degradation or to track restoration.

Effects of reduced pH and elevated pCO 2 on sperm motility and fertilisation success in blood clam, Tegillarca granosa - Wei Shi; Xinguo Zhao; Yu Han; Cheng Guo; Saixi Liu; Wenhao Su; Yichen Wang; Shanjie Zha; Xueliang Chai; Wandong Fu; Huicheng Yang; Guangxu Liu (New Zealand Journal of Marine and Freshwater Research, 2017)
Although it has been shown that ocean acidification generally has a negative impact on fertilisation success of broadcast spawning marine organisms, whether induced fertilisation success reduction is a consequence of elevated p CO 2 or decreased pH remains unclear. Therefore, the impacts of HCl‐ and CO 2 ‐induced acidified seawater on sperm motility and gametes fertilisation capability of a broadcast spawning bivalve species, Tegillarca granosa were investigated in the present study. The results showed that the fertilisation capability of both gametes was significantly reduced in either HCl‐ or CO 2 ‐acidified seawater. In addition, significant impacts on sperm motility were observed in the group exposed to CO 2 ‐acidified seawater, suggesting that this parameter is sensitive to p CO 2 instead of solely pH value. The differences between the two seawater acidification manipulating methods may be due to the intrinsic difference in diffusion capability of CO 2 and protons.

Pine afforestation affects key primary producers in mountain grassland streams in Córdoba, Argentina - Luciana Cibils‐Martina; Javier Márquez; Romina Principe; Noemí Gari; Ricardo Albariño (New Zealand Journal of Marine and Freshwater Research, 2017)
We evaluated changes in benthic algal community in grassland mountain streams converted to exotic pine afforestation. Three headwater streams draining grasslands and three draining plantations of Pinus elliottii were selected in a semiarid mountain watershed (Córdoba, Argentina). Hydraulic and physicochemical variables were recorded and benthic algal samples were collected in each stream at two hydrological periods (high and low flow). Light intensity was lower in afforested streams. Community composition differed between grassland and afforested streams. Algal abundance and richness, richness of chlorophytes and cyanobacteria, and the indicator taxa were reduced in afforested streams. Diversity, evenness and biomass were higher in the high water period but did not differ between riparian vegetation types. The observed changes in benthic algal attributes may have implications in ecosystem functioning because of the central role that algal biofilms play in the productivity of these fluvial systems, as sources of food, energy and oxygen.

Molecular and morphological characterisation of Sphaerolaimus haurakiensis n. sp. (Nematoda, Sphaerolaimidae) from the New Zealand continental shelf - Daniel Leduc; Zeng Qi Zhao (New Zealand Journal of Marine and Freshwater Research, 2017)
A new species of the predatory nematode genus Sphaerolaimus is described from the continental shelf off northeastern New Zealand, and an updated list of valid Sphaerolaimus species is provided. Sphaerolaimus haurakiensis n. sp. is characterised by eight longitudinal rows of 10–16 μm long somatic setae becoming gradually sparser posteriorly, six outer labial papillae and four 6–7 μm long cephalic setae in a single circle, amphideal fovea located at level of posterior buccal cavity, arcuate spicules 1.1 cloacal body diameters long, gubernaculum with curved apophyses almost parallel to the spicules, and vulva located at 55% of body length from anterior. S. haurakiensis n. sp. is the only valid species of this common, globally distributed genus recorded to date from the New Zealand Economic Zone, but several other species are likely to be present. Preliminary phylogenetic analyses based on sequences of the small subunit (SSU) 18S rDNA gene indicate that the new species is closely related to S. uncinatus Freudenhammer, 1970 a species found on continental margins of the Mediterranean and Northeast Atlantic.

Corrigendum (New Zealand Journal of Marine and Freshwater Research, 2017)

The dinoflagellate genera Gambierdiscus and Ostreopsis from subtropical Raoul Island and North Meyer Island, Kermadec Islands - Lesley L. Rhodes; Kirsty F. Smith; Arjun Verma; Sam Murray; D. Tim Harwood; Tom Trnski (New Zealand Journal of Marine and Freshwater Research, 2017)
An expedition to North Meyer Island, Kermadec Islands, in November 2015, resulted in the isolation of two Gambierdiscus species, G. australes and a previously unknown Gambierdiscus species maintained in the Cawthron Institute Culture Collection of Micro‐algae as CAWD242. Identifications were based on morphology and DNA sequence data analysis. Nine isolates of G. australes produced maitotoxin‐1 (MTX‐1) ranging from present (detectable but below the confidence level) to 36.6 pg per cell. One further isolate did not produce MTX‐1, but all G. australes isolates produced putative MTX‐3. Isolate CAWD242 was negative for MTX‐1 but produced MTX‐3. Ostreopsis sp. 3 isolated from samples collected during an earlier expedition in 2013 produced low concentrations of palytoxin (PLTX)‐like compounds (0.013 pg per cell), but an isolate of the same species from samples collected in 2015 was non‐toxic. Other dinoflagellates isolated and identified were Coolia malayensis , Amphidinium carterae and Prorocentrum hoffmannianum .

Assessment of the metabarcoding approach for community analysis of benthic‐epiphytic dinoflagellates using mock communities - Kirsty F. Smith; Gurjeet S. Kohli; Shauna A. Murray; Lesley L. Rhodes (New Zealand Journal of Marine and Freshwater Research, 2017)
In this study, we assessed the use of DNA metabarcoding as a method for biodiversity assessment of benthic‐epiphytic dinoflagellate communities and for detecting rare, toxin‐producing taxa. Mock communities and three primer pairs were used to establish the recovery of species signal and quantitative representation of species in the samples, as well as to determine primer biases, bioinformatic filtering steps, and threshold levels. Samples were analysed using high‐throughput sequencing Illumina ™ MiSeq technology. We did not find a relationship between read number and cell abundance for all treatments. However, the method was extremely sensitive, with two of the primer pairs detecting a single cell representing less than 0.001% of the cells in the sample. Benthic and epiphytic dinoflagellate communities were also collected from the Bay of Islands (Northland, New Zealand). Dinophyceae species richness was much higher when samples were analysed using metabarcoding than when analysed by microscopy, and we detected several new taxonomic records for New Zealand.

Wind‐driven upwelling and surface chlorophyll blooms in Greater Cook Strait - Stephen M. Chiswell; John R. Zeldis; Mark G. Hadfield; Matthew H. Pinkerton (New Zealand Journal of Marine and Freshwater Research, 2017)
We present the results of a combined observational and numerical study to investigate cool plumes of nutrient‐rich upwelled water that emanate near the Kahurangi Shoals and extend into Greater Cook Strait. Surface temperature and chlorophyll are mapped using satellite observations to produce surface climatologies, to validate a numerical simulation and to show the utility of using spatial temperature differences as a measure of upwelling. We find upwelling near the Kahurangi Shoals is strongly wind‐driven in the weather band. Upwelling occurs at all times of the year, but its surface signature is only visible in summer months. The upwelled nutrient‐rich water supports increased primary production compared to surrounding waters, particularly in summer when the water column is more stratified and surrounding surface waters are presumably nutrient depleted.

Issue Information (Reviews in Aquaculture, 2017)

Chinese Abstracts (Reviews in Aquaculture, 2017)

Application of machine vision systems in aquaculture with emphasis on fish: state‐of‐the‐art and key issues - Mohammadmehdi Saberioon; Asa Gholizadeh; Petr Cisar; Aliaksandr Pautsina; Jan Urban (Reviews in Aquaculture, 2017)
Demands of aquatic products are increasing dramatically during past decades. Also quality assurance has gradually received more attention by both producers and consumers. Thus, fish producers are exploring all possible approaches for improving the productivity and profitability. Monitoring of fish state and behaviour during cultivation may help to improve profitability for producers and also reduce the threat of severe loss because of disease and stress incidents. It is necessary to evaluate and measure quality of fish products in accurate, fast and objective way for meeting the different demands of the fish‐processing industry after harvesting. Traditional methods are usually time‐consuming, expensive, laborious and invasive. Using rapid, inexpensive and noninvasive methods is therefore important and desirable. Optical sensors and machine vision system provide the possibility of developing faster, cheaper and noninvasive methods for in situ and after harvesting monitoring of quality in aquaculture. This review describes the most recent technologies and the suitability of different optical sensors for the fish farming management and also assessment, measurement and prediction of fish products quality. Two major areas of optical sensors applications in aquaculture are discussed in this review: (i) preharvesting and during cultivation; and (ii) post‐harvesting. Finally, accuracy and uncertainty of optical sensors applications in aquaculture are discussed. This review showed that MVSs and optical sensors have found real‐world application based on tremendous possibility offered by digital camera development and increasing the speed of computer‐based processing; however, still new algorithms, methods and re‐engineered sensors need to be developed to meet real‐world requirements.

Socio‐cultural dynamics shaping the potential of aquaculture to deliver development outcomes - Miranda Morgan; Geraldine Terry; Surendran Rajaratnam; Jharendu Pant (Reviews in Aquaculture, 2017)
There is growing appreciation of the role of aquaculture in diversifying livelihoods of the poor. However, prevailing cultural norms and values, and social relations often influence its development outcomes, which we explore in this study. Socio‐cultural dynamics affect the capacity of resource‐poor and marginalized groups for the adoption and retention of aquaculture technologies. Gender norms and gender division of labour in a given community not only influence whether men or women participate in aquaculture but also shape their differential access to resources and position in decision‐making, with knock‐on effect for aquaculture productivity. Ethnic and cultural norms of collectivism, particularly in traditional fishing communities, support aquaculture efforts, but these are often overlooked by many development endeavours. Improved productivity does not necessarily translate into enhanced income, food and nutrition security. In many areas, benefits for women are lower despite their more active participation in aquaculture operations, post‐harvest processing and marketing compared to men. Local power relations may limit access to land and water resources as well as inputs and services by the poor, restricting more equitable distribution of income from aquaculture. Nutritional outcome from aquaculture largely depends on preferences and acceptability of fish as a food and local customs regarding its preparation, preservation, cooking and distribution. Aquaculture interventions that take resource base and socio‐cultural contexts into account are crucial for realizing increased income, food and nutrition benefits sustainably.

The utilization and mode of action of organic acids in the feeds of cultured aquatic animals - Wing‐Keong Ng; Chik‐Boon Koh (Reviews in Aquaculture, 2017)
The use of antibiotics in the feeds of cultured aquatic animals to mitigate infectious diseases or to boost growth performance is commonly practised. In recent years, the prophylactic use of antibiotics has been criticized which eventually led to their ban in animal production by many countries. In view of the current restrictions on antibiotic use, there is a critical need to evaluate alternatives. One potential substitute for antibiotic growth promoters in aquafeeds is organic acids and/or their respective salts. The use of dietary organic acids in the culture of aquatic animals has been the focus of much research and commercial interest recently. This review provides a comprehensive compilation of the current knowledge on the use of organic acids in aquafeeds, with emphasis on its impacts on growth, nutrient utilization, mineral availability, gut microbiota and disease resistance. Many studies have reported that some organic acids can significantly enhance the growth performance and health status of fish. Contradictory results have also been reported, which seems to depend on the aquatic animal species, type and concentrations of organic acids and the culture conditions used. Recent research indicating the beneficial impact of dietary organic acids on shrimp growth and health is highlighted. Possible mechanisms of action of these functional feed additives are discussed. Strategies for enhancing the effectiveness of dietary organic acids are given. This review aims to contribute to the sustainability of global aquaculture production by providing a viable alternative to harmful antibiotics, thereby meeting the growing consumer demand for antibiotic‐free seafood products.

Ocean acidification and marine aquaculture in North America: potential impacts and mitigation strategies - Jeff C. Clements; Thierry Chopin (Reviews in Aquaculture, 2017)
Shifting environmental conditions resulting from anthropogenic climate change have recently garnered much attention in the aquaculture industry; however, ocean acidification has received relatively little attention. Here, we provide an overview of ocean acidification in the context of North American aquaculture with respect to potential impacts and mitigation strategies. North American shellfish farms should make ocean acidification an immediate priority, as shellfish and other calcifying organisms are of highest concern in an increasingly acidifying ocean and negative effects have already been felt on the Pacific coast. While implications for various finfish have been documented, our current understanding of how acidification will impact North American finfish aquaculture is limited and requires more research. Although likely to benefit from increases in seawater CO 2 , some seaweeds may also be at risk under more acidic conditions, particularly calcifying species, as well as non‐calcifying ones residing in areas where CO 2 is not the primary driver of acidification. Strategies to mitigate and adapt to the effects of acidification exist on the regional scale and can aid in identifying areas of concern, detecting changes in seawater carbonate chemistry early enough to avoid catastrophic outcomes, and adapting to long‐term shifts in oceanic pH. Ultimately, ocean acidification has already imposed negative impacts on the aquaculture industry, but can be addressed with sufficient monitoring and the establishment of regional mitigation plans.

Sustainability vs. Quality in gilthead seabream ( Sparus aurata L.) farming: are trade‐offs inevitable? - Elisabete Matos; Jorge Dias; Maria T. Dinis; Tomé S. Silva (Reviews in Aquaculture, 2017)
European aquaculture industry should be at the forefront of sustainable development, providing healthy and safe food of the highest quality to the consumer, through an environmentally sound approach. The purpose of this review was to explore in what way the current drive for sustainability has affected what the consumer perceives as quality in fish, specifically in gilthead seabream, one of the most important farmed species in the Mediterranean. It focuses on nutritional aspects such as fish meal and fish oil replacement, quality tailoring through finishing strategies, the influence of different farming systems and the effect of slaughter stress on seabream quality. In general, fish meal and fish oil replacement with vegetable ingredients will result in changes in the fatty acid profile of the fillets, and consequently the potential health benefits seabream offers to the consumer. While organoleptic properties suffer little change, the impact of these ingredients on welfare has not been fully investigated. Further studies are also needed to evaluate the effect of land animal ingredients on seabream quality. In either case, although finishing strategies to restore essential fatty acids are not completely effective, seabream can still retain a high nutritional value. Information on the use of dietary supplements as finishing strategies is still extremely scarce. Regarding fish welfare, the high densities practised in intensive production systems pose concerns which warrant further research in this area. Furthermore, new alternatives for common harvesting and slaughter methods are needed to improve welfare, as traditional methods are clearly stressful.

Biomass and nutrient composition of temperate mangroves ( Avicennia marina var . australasica ) in New Zealand - Phan Tran; Iana Gritcan; Jarrod Cusens; Andrea C. Alfaro; Sebastian Leuzinger (New Zealand Journal of Marine and Freshwater Research, 2017)
Accurate estimates of biomass pools and their nutrient content are key for assessing the potential of vegetation to mitigate anthropogenic carbon emissions. In this study, we used the harvest method to estimate above‐ and below‐ground biomass (AGB and BGB) and nutrient content of the New Zealand mangrove Avicennia marina var . australasica at Mangawhai Harbour, northern New Zealand. AGB of A. marina was estimated at 5.7 ± 1.79 kg m −2 and BGB at 13.15 ± 1.55 kg m −2 (mean ± SE). The root‐shoot ratio at this site was 1.73. Fine roots contributed most to the total biomass (37%) followed by woody biomass (32%), coarse roots (27%), leaves (3%), and pneumatophores and seedlings (1%). Allocation of total carbon (TC) followed similar proportions as total biomass with was 64% in the roots, 33% in wood, and 3% in the leaves (by dry mass). Roots contained 64% of total nitrogen (TN) and 53% of total phosphorus (TP) (by dry mass). In leaves, TN was 5% and TP was 6% with the remaining nutrients in woody biomass. The foliar N:P ratio was 8.2, suggesting nitrogen limitation at this site. Based on these results, we estimate that New Zealand mangroves store a total of 0.2–1.1 Mt carbon (C) above ground and 1.06–1.72 Mt C below ground.

Multi‐decadal shoreline change and beach connectivity in a high‐energy sand system - Brendon Blue; Paul S. Kench (New Zealand Journal of Marine and Freshwater Research, 2017)
Understanding how and why the world’s coastlines are changing is a pressing international concern in a context of rising sea levels, increased climatic variability and intensifying coastal development. Medium to long‐term records of coastal change are rare worldwide and often limited to individual beach compartments. This study presents a 70‐year (1940–2010) aerial imagery record to compare decadal changes in shoreline position across four high‐energy west coast beaches near Auckland, New Zealand/Aotearoa: Whatipu, Karekare, Piha and Te Henga (Bethells). The common exposure of these adjacent mesotidal beaches to changing wind and wave conditions might, if they present the dominant controls on shoreline position, be expected to produce synchronous change. Whatipu (935 m), Piha (32 m) and Te Henga (52 m) showed net overall progradation for the study period, while Karekare retreated slightly (−4.1 m). All except Whatipu underwent periods of beachwide erosion. Shoreline change was not coherent between beaches, despite similar exposure to variations in wind, wave and sea level. Variable sediment supply from northward littoral drift is implicated as the primary control on decadal‐scale shoreline change for these beaches, highlighting the importance of local context in influencing shoreline response to changing environmental conditions.

Acute toxicity of copper, lead, zinc and their mixtures on the sea urchin Evechinus chloroticus - Agnes M. Rouchon; Nicole E. Phillips (New Zealand Journal of Marine and Freshwater Research, 2017)
Coastal pollution is complex, often consisting of multiple contaminants, and it is increasingly recognised that exposure to combinations of pollutants can produce different outcomes than each does separately. This study investigates the toxicity of three major pollutants in coastal environments (copper, lead and zinc) individually and in binary mixtures on larvae of Evechinus chloroticus , a sea urchin endemic to New Zealand. Larval development assays were conducted for 72 h. Median effective concentrations (EC50) for normal larval development for individual metals were 5.4 μg/L Cu, 52.2 μg/L Pb and 27.7 μg/L Zn. Evechinus chloroticus was more sensitive to copper and zinc than most echinoid species tested to date. Effects of metal mixtures were analysed using a toxic unit (TU) approach. Cu + Zn and Cu + Pb had a less‐than‐additive effect on E. chloroticus larval development. By contrast, Zn + Pb was strictly additive. None of the interactions were strong, with sums of TU ranging from 1.00 to 1.85. These results support the use of criteria based on strictly‐additive models to determine whether these three metals exceed water quality thresholds when occurring in a simple mixture.

Impacts of a bivalve mass mortality event on an estuarine food web and bivalve grazing pressure - Hannah F. E. Jones; Conrad A. Pilditch; David P. Hamilton; Karin R. Bryan (New Zealand Journal of Marine and Freshwater Research, 2017)
Declines in bivalve populations have been quite common worldwide, often associated with coastal development, pollution and climate change. In addition to the impacts of these chronic stressors, occasional mass mortality events may have severe consequences on ecosystem services and biodiversity. In this study, we examined the impact of a mass mortality event of the clam ( Austrovenus stutchburyi ) on an estuarine food web and the grazing pressure exerted by the bivalve population. In February 2009, c. 60% of the clam population died in Whangateau Harbour, New Zealand. Population clearance rate calculations suggest that the clam population do not exert significant top‐down control on phytoplankton biomass in the estuary, and thus the impact of the mortality event on bivalve grazing pressure was less severe than the reduction in abundance would suggest. A trophic model shows that phytoplankton play a limited role in the estuary food web, which is instead dominated by microphytobenthos and clams. This study highlights the importance of microphytobenthos in shallow estuaries, and the application of the trophic model is a useful tool that can identify key components of the ecosystem and could help inform monitoring programmes.

Preservatives and sample preparation in stable isotope analysis of New Zealand freshwater invertebrates - Kristy L. Hogsden; Peter A. McHugh (New Zealand Journal of Marine and Freshwater Research, 2017)
Interpretation of stable isotope data needs to take into account known, but often variable and inconsistent, influences of preservatives and lipids on carbon and nitrogen isotopic values. We tested how short‐term ( 13 C and δ 15 N values of 10 common New Zealand stream invertebrates and assessed whether mathematical lipid corrections (derived overseas) are valid here. The different methods significantly affected δ 13 C but not δ 15 N values. Specifically, ethanol‐preserved and lipid‐extracted samples were enriched in δ 13 C (by 1–2 ‰) relative to frozen samples. Short‐term storage in ethanol (70%) was comparable to lipid removal and similar δ 13 C values were obtained when frozen samples were corrected mathematically. In contrast, δ 15 N values differed i ) lipid extraction or mathematical correction may be unnecessary for ethanol‐preserved samples, as ethanol appears to behave as a lipid solvent; ( ii ) existing mathematical corrections can adequately adjust for lipid‐related shifts in δ 13 C in frozen samples; and ( iii ) δ 15 N values lend similar insight regardless of preservation/preparation methods. Although these results support the notion that archived (ethanol‐preserved) invertebrate samples can inform isotope studies, additional work is needed to determine storage durations to which our findings apply.

Trimethylamine oxide content and spoilage potential of New Zealand commercial fish species - G. Summers; R. D. Wibisono; D. I. Hedderley; G. C. Fletcher (New Zealand Journal of Marine and Freshwater Research, 2017)
Breakdown of trimethylamine oxide (TMAO) during post‐harvest storage contributes significantly to loss of seafood quality. We surveyed 51 New Zealand commercial fish species and determined white muscle tissue concentrations of TMAO and the TMAO‐derived spoilage indices: trimethylamine nitrogen (TMA‐N) and total volatile basic nitrogen (TVB‐N). There were significant differences in the TMAO concentrations between fish of various genus and species. Values ranged between 8 and 789 mg/100 g for ray‐finned fishes (Actinopterygii), and 262 and 789 mg/100 g for cartilaginous fishes. The distribution of TMAO was similar to that of Northern Hemisphere fish species. Deep water species had the highest concentrations of TMAO. Seasonal effects in tarakihi ( Nemadactylus macropterus ) and red gurnard ( Chelidonichthys kumu ) were studied and TMAO declined significantly over the summer months. TMA‐N was typically below 2 mg/100 g and TVB‐N concentrations did not exceed the limits set by the European Community (EC) Commission Regulation No. 1022/2008.

Accumulation of nodularin in New Zealand shortfin eel ( Anguilla australis ): potential consequences for human consumption - B Dolamore; J Puddick; SA Wood (New Zealand Journal of Marine and Freshwater Research, 2017)
The native Anguilla australis (shortfin eel) is a culturally significant species for indigenous Māori populations of New Zealand. At Lake Forsyth/Te Wairewa (Canterbury), local Māori have depended on A. australis as a source of mahinga kai (traditional food) for centuries. This lake experiences blooms of Nodularia spumigena and the associated hepatotoxin nodularin has been detected in water samples. This study aimed to determine if nodularin accumulated in A. australis , and whether levels posed a health risk for human consumption. The maximum concentrations of N. spumigena and nodularin detected in lake water samples were 240 × 10 6 cells/mL and 91,000 µg/L, respectively. Nodularin was detected in the liver and muscle of eels (max. 147 µg/kg in liver and 29 µg/kg in muscle). One muscle sample exceeded the recommended levels for safe human consumption of nodularin in fish (24 μg/kg).

Acute toxicity of arsenic to larvae of four New Zealand freshwater insect taxa - Olivier Champeau; Jo Anne E. Cavanagh; Thomas J. Sheehan; Louis A. Tremblay; Jon S. Harding (New Zealand Journal of Marine and Freshwater Research, 2017)
Arsenic, often found in gold deposits, can enter aquatic systems. The toxicity of arsenate (As(V)), the most common valence state of arsenic in freshwater, was assessed on the larvae of four freshwater insect taxa from naturally acidic (pH 5.9) and circumneutral (pH 7.4) New Zealand streams. Insects from the acidic stream were more sensitive to arsenate‐spiked water than those from the circumneutral stream. Early instars ( Deleatidium spp. (Leptophlebiidae) were the most sensitive compared to later instars (3–6 mm) (4‐d LC 50 1.5 and 3.5 mg/L, respectively) or to the stonefly Zelandobius spp. (Gripopterygidae) (4‐d LC 50 2.5 mg/L). The cased caddisflies Pycnocentria spp. (Conoesucidae) and Helicopsyche spp. (Helicopsychidae) from circumneutral stream were the most tolerant (4‐d LC 50 45.4 and 113 mg/L, respectively). The 14‐day arsenic LC 10 and LC 50 for Deleatidium spp. late instars exposed to mining‐impacted water were 0.12 and 0.36 mg/L, respectively.

First report of a rickettsia‐like organism from farmed Chinook salmon, Oncorhynchus tshawytscha (Walbaum), in New Zealand - C. L. Brosnahan; H. J. Ha; K. Booth; A. M. J. McFadden; J. B. Jones (New Zealand Journal of Marine and Freshwater Research, 2017)
In the summer months of 2015 Chinook salmon, Oncorhynchus tshawytscha (Walbaum), were submitted to the New Zealand Ministry for Primary Industries (MPI) for disease investigation. Gross examination of 10 moribund fish revealed multiple areas of ulceration over all areas of the body including fins and mouth in eight of the 10 fish. Pale livers ( n = 4), mottled appearance of the kidney ( n = 5) and reddening of the distal intestines ( n = 5) were also observed. As these fish presented with skin lesions, Piscirickettsia salmonis was included as a differential diagnosis. Testing for this agent was conducted and a rickettsia ‐ like organism (RLO) was detected by histopathology in seven fish and by molecular methods in three fish. Nucleic acid sequencing revealed that this organism had highest similarity to a piscirickettsia‐like organism with a 19 base pair (bp) deletion in the internal transcribed spacer (ITS) region of the rDNA operon when compared to the reference strain P. salmonis , LF‐89 (ATCC VR‐1361). The variation was similar to that of the Tasmanian RLO detected in Atlantic salmon, Salmo salar L (GenBank accession number AY578985). Based on these sequence variations, a tentative identification of New Zealand rickettsia‐like organism (NZ‐RLO) was suggested. NZ‐RLO is not considered to be the primary cause of the mortalities in these fish, with the primary cause still under investigation. This is the first report of a RLO in New Zealand farmed salmon.

Chinese Abstracts (Reviews in Aquaculture, 2017)

Issue Information (Reviews in Aquaculture, 2017)

Use of phytases in fish and shrimp feeds: a review - Daniel Lemos; Albert G. J. Tacon (Reviews in Aquaculture, 2017)
Phytases have been employed in animal feeds for several years, used primarily for reducing the environmental impact and phosphorus loads of farm effluents. Beneficial effect of dietary phytase has been associated with the limited ability of monogastric animals to utilize dietary plant phytates. To date, numerous studies have shown the positive effect of phytase supplementation on the availability of dietary phosphorus and trace minerals within plant‐based feeds for monogastric farm animals, including farmed fish and shrimp. Individual feed ingredients may also be improved with phytases as an exogenous treatment, also termed pre‐conditioning dephytinization prior to mixing. This review presents data on the potential benefit of phytase application for fish and shrimp species in improving digestibility of phosphorus and other minerals as well as organics nutrient fractions such as protein, amino acids and lipids.

Impacts of environmental and biological stressors on immune system of Macrobrachium rosenbergii - Venkatesh Kumaresan; Rajesh Palanisamy; Mukesh Pasupuleti; Jesu Arockiaraj (Reviews in Aquaculture, 2017)
Macrobrachium rosenbergii commonly called giant freshwater prawn is a widely farmed crustacean in freshwater. Similar to other aquatic organisms, their growth and well‐being is influenced by various physical, chemical and biological factors. We discuss about the critical growth limiting factors as well as disease causing agents and the potential immune molecules of M. rosenbergii that are proved to involve in preventing and/or responding to those limiting factors.

Harvesting time optimization and risk analysis for the mariculture of K appaphycus alvarezii ( R hodophyta) - Roger Domínguez‐May; Eucario Gasca‐Leyva; Daniel Robledo (Reviews in Aquaculture, 2017)
Kappaphycus alvarezii (Rhodophyta) is an important source of carrageenan, which is commercially cultivated with economic benefits worldwide. In this study, we determined the optimal harvesting time and risk analysis for the mariculture of K. alvarezii in a semi‐intensive commercial cultivation farm using a simulation model. Different growth models were analysed (Von Bertalanffy, Potential, Logistic and Gompertz) for the bioeconomic model developed in this study. Seawater temperature and solar irradiance functions were included as variables with major influence on seaweed growth. The Gompertz growth equation was chosen in accordance with Theil′s statistics and the difference between observed and simulated data. Under the conditions and assumptions considered for this analysis, the scenario that generated the highest profits ( USD $ 3353.11) was that for a culture cycle of 135 days and a total biomass production of 13 708.47 kg dry weight cycle −1 . Uncertainty was also included using probability density functions through random variables for seawater temperature, solar irradiance and sale price. Different harvest scenarios were obtained through Monte Carlo analysis; decisions under risk conditions and probabilities of being above or below reference points are presented. The results indicated lower risk at optimum harvesting time when the probability of exceeding the established target reference point for the present value ( USD $ 2515.15) and biomass produced (34 271.17 kg fresh weight) were around 19.26% and 56.47%, respectively. Discussion on the implications of the use of this analysis for seaweed cultivation management is presented.

Strategies for managing diseases in non‐native shrimp populations - James Cock; Marcela Salazar; Morten Rye (Reviews in Aquaculture, 2017)
The shrimp industry is now largely based on Litopenaeus vannamei . Current strategies for disease management in Asia emphasizing exclusion and eradication with strict quarantine and importation protocols have not been effective in controlling disease epidemics. New diseases have been introduced on illegal importations; commercial shrimp populations are derived from imported SPF stocks susceptible to endemic diseases; and local breeding programmes are based on populations not resistant to a range of diseases. Broodstock are largely poorly adapted to local conditions and repeated disease epidemics occur. Strategies for disease management should concentrate on: (i) minimizing the risk of introducing new diseases to the region; (ii) development of populations more resistant to endemic diseases; and (iii) better management practices that minimize the likelihood of serious epidemics and delay infection, but do not depend on attempts to eradicate diseases already present. This can be implemented by building on the better management practices already established in the region and in addition: (i) applying strict quarantine procedures for diseases not reported in the region whilst making the processes sufficiently agile to reduce illegal introductions; (ii) eliminating standard rigid importation protocols and tailoring protocols in accordance with the disease situation of both the country of origin and destination; (iii) increasing genetic variation available within Asia by public sector support for programmes to enlarge the pool of genetic variation and encouraging collaboration with breeding programmes that encompass a broad genetic base; (iv) establishing selection programmes that permit reincorporation of animals exposed to disease into the breeding nucleus; and (v) establishing propagation systems that provide growers with high health status stocks without requiring overly strict SPF certification of facilities.

Coral propagation: a review of techniques for ornamental trade and reef restoration - Jonathan A. Barton; Bette L. Willis; Kate S. Hutson (Reviews in Aquaculture, 2017)
Aquaculture of coral offers an alternative to wild harvest for the ornamental trade and shows considerable promise for restoring reefs and preserving biodiversity. Here, we compare advantages and disadvantages of asexually derived fragments versus sexually derived propagules and in situ versus ex situ nursery phases for the ornamental trade and reef restoration. Asexual propagules, sourced from a donor coral colony that is cut into smaller parts and attached to artificial substrate, are most commonly used. The most suitable corals are typically branching species, although fragments from species with other growth forms can be successful, albeit slower growing. Sexually derived propagules are collected from the wild or from colonies in aquaria during spawning, with an artificial substrate provided for settlement. The timing of spawning is known for many broadcast spawning corals, but opportunities for collection of gametes are generally limited to only once or a few times per year. Brooding species with multiple periods of larval release provide better options for culture of sexually derived propagules. Propagation techniques have developed considerably over the past 20 years, yielding faster growth rates, reduced mortality and reduced detachment from substrates. Simple and cost–effective propagation techniques can be used to restore denuded reefs, preserve endangered species, provide live corals to the international ornamental trade, enable livelihood diversification for coastal communities and provide experimental materials for marine research. This review provides a comprehensive synthesis of recent developments in aquaculture propagation techniques for the purpose of ornamental trade and coral reef restoration, including asexual and sexual propagation, nursery and transplantation stages.

Identifying risk factors associated with White Spot Disease outbreaks of shrimps in the Gulf of California (Mexico) through expert opinion and surveys - Ana Muniesa; Ricardo Perez‐Enriquez; Julio Cabanillas‐Ramos; Francisco J. Magallón‐Barajas; Cristina Chávez‐Sánchez; Héctor Esparza‐Leal; Ignacio de Blas (Reviews in Aquaculture, 2017)
White spot disease is one of the most serious problems in the shrimp‐farming industry in Mexico. An assessment of risk of an outbreak of the disease could be useful for farmers making decisions concerning early harvest to minimize economic losses. A group of researchers identified the most important risk factors, classified in four broad categories: management variables at the regional level, environmental variables at the regional level, management variables at the farm and population variables at the farm. For each variable, categories were defined and a risk score assigned. To validate these scores, a survey was carried out with 65 stakeholders. A semi‐quantitative risk assessment model was proposed and implemented as a questionnaire containing 21 risk variables with weighted scores. The most important risk factors were the period of fallowing within farm's region and health quality of larvae. Also important were estimated level of viral load and virus detection in wild hosts in the surrounding area, pond water temperature, length of fallowing period of pond, vector control at water intake and stocking density. The overall estimated risk was calculated as the sum of all scores with a further adjustment, according to maximum and minimum total scores. Three risk levels for white spot disease outbreak at ponds are based on estimated risk: low (≤0.2), moderate (0.2–0.4) and high (≥0.4).

Coastal adaptation to climate change in Aotearoa‐New Zealand - HL Rouse; RG Bell; CJ Lundquist; PE Blackett; DM Hicks; D‐N King (New Zealand Journal of Marine and Freshwater Research, 2017)
The most recent Intergovernmental Panel on Climate Change reports conclude that for Australasia, without adaptation, further changes in climate, atmospheric CO 2 , sea‐level rise and ocean acidity are projected to have substantial impacts on climate sensitive systems, sectors and populations. In the context of varying geographical, social, cultural and policy contexts, this paper reviews research contributions and activities concerning coastal adaptation to climate change in Aotearoa‐New Zealand. It reflects on the insights derived from this emerging pool of scholarship and considers what lessons have been learned to help us address the future challenges of adaptation to climate change on our coasts and estuaries. In particular, future progress will require strong understanding of natural coastal systems, clearer national direction and guidance in balance with regional flexibility, and collaborative processes to help communities understand, implement and evaluate adaptation pathways for a sustainable and resilient future.

Influence of linoleic acid on growth, oxidative stress and photosynthesis of the cyanobacterium Cylindrospermopsis raciborskii - S Xu; S‐Q Yang; Y‐J Yang; J‐Z Xu; J‐Q Shi; Z‐X Wu (New Zealand Journal of Marine and Freshwater Research, 2017)
In this study, the effects of linoleic acid on the growth, photosynthetic activities and oxidative system of the invasive cyanobacterium Cylindrospermopsis raciborskii were investigated. The results indicated that linoleic acid decreased the growth rate and chlorophyll a concentration in C. raciborskii after 48 h incubation. The maximum photochemical efficiency ( F v / F m ) of photosystem II (PSII) and maximum relative electron transport rate (ETR max ) decreased significantly at concentrations higher than 1 mg L −1 . However, non‐photochemical quenching (NPQ) significantly increased when cultured at concentrations of 0.5, 1, 2 and 4 mg L −1 . PSII electron transfer rate and chlorophyll a fluorescence transients appeared to be affected after the cells were exposed to higher concentrations of linoleic acid; the density of the reaction centres (RCs), quantum energy flux ratios and the performance index on absorption basis decreased, but absorption flux per RC and dissipated energy flux per RC increased. Malondialdehyde content, superoxide dismutase and catalase activities were enhanced when exposed to 2 and 4 mg L −1 of linoleic acid. This suggests that the blockage of electron transport on the donor and acceptor sides of PSII is the mechanism responsible for the toxicity of linoleic acid in PSII of C. raciborskii .

Effect of body size and temperature on respiration of Galaxias maculatus (Pisces: Galaxiidae) - D Milano; PH Vigliano; DA Beauchamp (New Zealand Journal of Marine and Freshwater Research, 2017)
Body mass and temperature are primary determinants of metabolic rate in ectothermic animals. Oxygen consumption of post‐larval Galaxias maculatus was measured in respirometry trials under different temperatures (5–21 °C) and varying body masses (0.1–>1.5 g) spanning a relevant range of thermal conditions and sizes. Specific respiration rates ( R in g O 2 g −1 d −1 ) declined as a power function of body mass and increased exponentially with temperature and was expressed as: R = 0.0007 * W −0.31 * e 0.13 * T . The ability of this model to predict specific respiration rate was evaluated by comparing observed values with those predicted by the model. Our findings suggest that the respiration rate of G. maculatus is the result of multiple interactive processes (intrinsic and extrinsic factors) that modulate each other in ‘meta‐mechanistic’ ways; this would help to explain the species’ ability to undergo the complex ontogenetic habitat shifts observed in the lakes of the Andean Patagonic range.

Influence of seasonal freshwater streamflow regimes on phytoplankton blooms in a Patagonian fjord - JL Iriarte; J León‐Muñoz; R Marcé; A Clément; C Lara (New Zealand Journal of Marine and Freshwater Research, 2017)
Large‐scale regional phenomena and global climate trends may alter the freshwater discharge of large Patagonian rivers and could modify local circulation patterns in ways that influence phytoplankton dynamics. Modifications detected in the streamflow regime of the Puelo River (41.5° S, Patagonia, Chile) in recent decades may affect the regularity of seasonal phytoplankton blooms in Reloncaví Fjord. We examined the occurrence/frequency of spring–summer and autumn phytoplankton blooms in Reloncaví Fjord with respect to seasonal and inter‐annual changes in freshwater streamflows from 2003 to 2011. Surface chlorophyll‐a derived from satellite‐ocean colour and phytoplankton abundances revealed that significant recurrences of autumn phytoplankton blooms (> 2 mg Chl‐a m −3 , > 500 cell mL −1 ) were associated with historical low mean freshwater streamflows, mainly in autumn ( 3 s −1 ). On the other hand, the occurrence of spring–summer blooms was related to high streamflows (> 470 m 3 s −1 ) that increased mixing in the upper photic layer enough to enhance phytoplankton growth. Our findings imply that the intensity of autumn blooms in Reloncaví Fjord could be modulated by streamflow strength.

Sediment turnover by the stalk‐eyed mud crab Hemiplax hirtipes (Brachyura: Ocypodoidea) on an intertidal flat in southeastern New Zealand - AA Rowden (New Zealand Journal of Marine and Freshwater Research, 2017)
Bioturbation by the stalk‐eyed mud crab Hemiplax hirtipes was quantified via simple non‐invasive, non‐destructive means, to produce a relatively comprehensive estimate of annual sediment turnover. A linear correlation was found between the number of crab burrow holes and crab density, and between sediment excavation mound area and dry weight. Thus, crab density was determined by burrow hole count, and sediment excavation by photography and image analysis. Crab size and sex were ascertained by direct measurement and observation in the field. Burrows and their occupants were sampled once a month for 12 months. Annual sediment turnover (43 kg dry weight m −2 yr −1 ) was estimated by integrating the relationships established between crab size and the quantity of sediment excavated, plus the influences of temporal change in population density and size structure. Hemiplax hirtipes is likely to be a key bioturbating species influencing ecosystem structure and function where it occurs in relatively high densities on intertidal flats in New Zealand.

Asexual origin of brooding in the sea anemones Actinia equina and A. schmidti : molecular evidence from the Portuguese shore - AM Pereira; E Cadeireiro; JI Robalo (New Zealand Journal of Marine and Freshwater Research, 2017)
Reproduction by sexual or asexual viviparity is a common phenomenon in some anemone species. In this short communication, the origin of the brooded young of Actinia equina and A. schmidti from the Portuguese shore was investigated. DNA was extracted from 56 brooding adult Actinia sp. and the nuclear gene that codes for the 28S ribosomal subunit was sequenced. Species identity was then assessed using GenBank. In total, 50 individuals were A. schmidti , five were A. equina and one had a hybrid origin. Three adult anemones (the hybrid, one A. equina and one A. schmidti ) possessed two different 28S sequences and so their offspring was selected for further analysis using the same molecular procedure. Each brooded polyp was found to possess the exact same sequence as its parent, strongly suggesting the asexual origin of broods in A. equina and A. schmidti .

Effects of mechanical macrophyte control on suspended sediment concentrations in streams - MJC Greer; AS Hicks; SK Crow; GP Closs (New Zealand Journal of Marine and Freshwater Research, 2017)
Suspended sediment (SS) is an important pollutant in freshwater ecosystems and can be detrimental to fish communities. Although macrophytes mediate sediment deposition, little effort has been put into determining how their removal affects sediment resuspension. The present study examined the immediate and long‐term impacts of mechanical macrophyte removal on SS concentrations in streams. The results of this study suggest that bed disturbance during mechanical excavation of macrophytes significantly increases SS in the short term, and concentrations were found to increase by as much as 15,687 mg L –1 immediately after macrophyte removal. Significant long‐term (77 day) increases in SS were also observed, indicating that without macrophytes, disturbed material is continually resuspended after excavation by fluvial processes. These results demonstrate that macrophyte removal can result in SS levels that have previously been shown to harm fish, and indicate that this activity may be more detrimental to fish than previously thought.

Spatial‐temporal changes of the morphodynamic beach state before and after the 2010 mega‐earthquake and tsunami along south‐central Chile - R Veas; E Hernández‐Miranda; C Martinez; D Lercari; RA Quiñones (New Zealand Journal of Marine and Freshwater Research, 2017)
Sandy beaches are characterised by high temporal and spatial variability, resulting in environmental gradients between beaches based on morphodynamic differences. This variability is less well known when beaches are affected by abrupt and highly energetic perturbations such as earthquakes and tsunamis. Here, we analysed the changes in the morphodynamic characteristics of six beaches in south‐central Chile. Morphodynamic variables were analysed seasonally, and as a function of changes caused by a mega‐earthquake and subsequent tsunami on 27 February 2010 (Mw = 8.8). The results indicate that Dichato and Lenga have reflective morphodynamic states, while Cobquecura, Mela, Perales and Puda have intermediate states. The canonical analysis of principal coordinates (CAP) biplot of the first two components showed that the second component (CAP2) related Dichato and Mela significantly to mean grain size, frequency of effluent line crossing, swash frequency, breaking wave frequency and swash speed; while Cobquecura, Perales, Puda and Lenga were related to beach slope, height of breaking wave and swash frequency. Beaches generally showed coarse sand during winter and lower textural range in summer, but with high seasonal variability of mean grain size. The mega‐earthquake and subsequent tsunami that hit the study area in February 2010 led to short‐term changes in morphodynamics, mainly beach slope and granulometry, but beaches tended to regain conditions similar to those prior to the earthquake, showing an apparent high resilience to this strong natural perturbation.

Chinese Abstracts (Reviews in Aquaculture, 2017)

Issue Information (Reviews in Aquaculture, 2017)

A comparative analysis of four internationally traded farmed seafood commodities in China: domestic and international markets as key drivers - Wenbo Zhang; Francis J. Murray; Liping Liu; David C. Little (Reviews in Aquaculture, 2017)
The historical development, current status and development trends of four internationally traded farmed seafood commodities, tilapia, penaeid shrimp, macrobrachium prawns and catfish in China were reviewed. China is the world's largest producer of tilapia, penaeid shrimp and macrobrachium prawns but, although farming of channel catfish and some indigenous catfish species is well developed, striped catfish failed to become established. In terms of global exports, China ranks first for tilapia and third for shrimp, while macrobrachium prawns and catfish mainly support domestic markets. Endogenous, biological characteristics and market demand explain the different courses of development and the differentiated focus on domestic and international trade. Tilapia and whiteleg shrimp production illustrated rapid growth in both domestic and international markets based on their favourable culture characteristics and well‐developed management systems. Huge production scale and domestic competition have resulted in China attaining a dominant and highly competitive position in the global tilapia market. High value of live freshwater prawns in local markets (and poor processing yield) has limited interest in exports, and local demand is also shifting the emphasis of shrimp production towards domestic markets, and a decline in its international market led to stagnation of channel catfish. Poor tolerance of seasonally low temperatures has restricted tilapia production to south China and completely inhibited the development of striped catfish as a commercial species. Live fish preference and costs of long‐distance transportation have restricted domestic consumption of tilapia. A balance between domestic consumption and export is required to optimise future growth opportunities for the industry.

A review of carotenoid utilisation and function in crustacean aquaculture - Nicholas M. Wade; Jacques Gabaudan; Brett D. Glencross (Reviews in Aquaculture, 2017)
Crustaceans are cultured extensively around the world in intensive farming systems. High‐performance formulated feeds have been developed for crustacean aquaculture, which are often supplemented with a number of natural and synthetic carotenoid sources. Studies over a number of years have consistently shown that dietary carotenoid supplementation is beneficial for crustacean aquaculture across a range of commercially relevant parameters. Most obvious is the effect on pigmentation, where carotenoid inclusion levels in feeds and duration of feeding diets with carotenoids have been optimised across many species to improve product colour, and subsequently quality and price. However, beneficial effects of carotenoid inclusion have increasingly been demonstrated on other parameters. This review updates the recent progress in our understanding of dietary carotenoid utilisation and storage, and the combined effects of diet, genetics and environment on crustacean pigmentation. In addition, the range of other physiological benefits this class of molecules brings to these animals is summarised. These include improvements in survival, growth, reproductive capacity, disease resistance and stress resistance.

Planning and management for sustainable coastal aquaculture development in Santa Catarina State, south Brazil - Felipe M. Suplicy; Luiz F. de Novaes Vianna; Guilherme S. Rupp; André L. T. Novaes; Luis H. P. Garbossa; Robson V. de Souza; João Guzenski; Sérgio W. da Costa; Fabiano M. Silva; Alex A. dos Santos (Reviews in Aquaculture, 2017)
Marine aquaculture of bivalve molluscs is an important economic activity in Santa Catarina State, Brazil, with more than 5000 persons directly and indirectly involved and an annual revenue of US $ 18 million in 2013. In the first decade of this activity, a lack of proper regulation imposed multiple obstacles to the sustainable management of local shellfish farming. The occupation of marine space occurred in a disorderly manner, and the unplanned development led to unfavourable conditions that threatened the sustainability of the industry. This study describes how better planning and management tools have improved governance of marine aquaculture in Santa Catarina State. The process included development of a legal framework for aquaculture planning, elaboration of local development plans with a participatory and multidisciplinary approach, development of a geographic information system to identify favourable areas and creation of a Web‐based aquaculture management system. The combined application of these actions, along with continuing extension services, is expected to contribute to the regulation of 837 shellfish farming areas, the expansion of farming activity, the mitigation of the environmental and visual impacts caused by coastal aquaculture and an increase in the public health of shellfish consumers. In this manuscript, we report an example of how the application of better planning and management of the aquaculture sector can prepare the industry for a sustainable growing cycle.

A bioeconomic approach to optimize mussel culture production - Isabel Fuentes‐Santos; Alhambra M. Cubillo; Uxío Labarta (Reviews in Aquaculture, 2017)
The fast rise of aquaculture practices during the last decades has increased the need of adopting culture strategies to optimize production and guarantee the sustainability of the sector. This study aimed to provide a management tool to help mussel farmers identify optimal culture strategies and use production inputs efficiently. For this purpose, we evaluated the productivity and efficiency of different stocking densities and culture durations by the joint application of parametric and nonparametric frontier analysis at the farm scale. The translog production function outperformed the Cobb–Douglas model currently applied in most farm‐scale frontier analyses. This model estimates that the optimal culture density is ca. 700 ind m −1 , given that at lower densities, efficiency decreases (under‐usage of available space) and mussel quality did not improve, and at higher densities, mortality and dislodgements from the ropes led to economic losses. This work also showed that marginal analysis does not provide an accurate estimation of the economic efficiency when unitary costs and prices are not constant. According to the Malmquist indices, mussel farmers should shorten the culture period to improve their productivity. All these results support the joint use of parametric and nonparametric frontier analysis as management tool for optimizing input use and scheduling aquaculture production.

Lymphocystis disease virus: its importance in aquaculture - Juan J. Borrego; Estefania J. Valverde; Alejandro M. Labella; Dolores Castro (Reviews in Aquaculture, 2017)
Lymphocystis disease virus ( LCDV ) is the causative agent of a well‐known fish viral disease that is characterized by hypertrophy of fibroblastic cells in the connective tissue. This viral disease affects more than 125 wild and cultured species of teleost fish from marine and freshwater environments and has a cosmopolitan geographical distribution. In aquaculture systems, the prevalence of LCDV infection is very high, likely reflecting the horizontal transmission of this virus. The incidence rate of the disease may reach 70%, causing significant economic losses for the aquaculture industry. This review provides information on the taxonomy, viral properties, epizootiology and pathogenesis, diagnostic methods and control measures of LCDV infection in fish.

Analysis on the development and current situation of rainbow trout ( Oncorhynchus mykiss ) farming in Mexico - César Ortega; Benjamín Valladares (Reviews in Aquaculture, 2017)
The rainbow trout ( Oncorhynchus mykiss ), originally from North America, was introduced to Mexico in 1888 and gradually distributed to various areas of the country. Currently, rainbow trout are cultivated in Mexico under a number of production systems, but this sector has grown less than 1% annually for the last 10 years. The present review analysed the production status of rainbow trout in Mexico, describing the key situations and actors that have influenced the establishment and current level of aquaculture development. Since its beginnings, rainbow trout cultivation in Mexico has depended on egg import due to insufficient egg and fry production by national hatcheries. Moreover, the industry is deficient in regard to a number of aspects in the production and management processes, with a notable necessity for specialists in the areas of production, health and sanitary diagnosis to rapidly and efficiently respond to situations such as low productivity or the presence of diseases. With such specialists, appropriate control and prevention decisions could be taken and acted upon. Likewise, the Mexican rainbow trout industry has high development potential and market expectations, but sector growth will require the active participation and commitment of competent authorities, in compliance with established Mexican regulations and laws, which are oriented towards advancing and protecting the fish farming industry.

Multiple lines of evidence determine robust nutrient load limits required to safeguard a threatened lake/lagoon system - M. Schallenberg; D. P. Hamilton; A. S. Hicks; H. A. Robertson; M. Scarsbrook; B. Robertson; K. Wilson; D. Whaanga; H. F. E. Jones; K. Hamill (New Zealand Journal of Marine and Freshwater Research, 2017)
Three independent scientific lines of evidence were sought to determine the nutrient load limits to safeguard the macrophyte community of an intermittently closed and open lake/lagoon (ICOLL): (1) a literature review identified nitrogen load thresholds related to the collapse of macrophytes in similar systems in Australia, Europe and elsewhere, (2) an ICOLL expert carried out an assessment based on current local data and on data from 57 Australian coastal lakes and lagoons, and (3) a deterministic coupled hydrodynamic‐ecological model was developed and applied to simulate the ecological outcomes of several nutrient loading scenarios. The three lines of evidence converged on well‐defined nitrogen load estimates required to avoid the collapse of the macrophyte community. Uncertainties were slightly greater in relation to required phosphorus load limits, but the evidence still helped set a precautionary phosphorus load limit that accounted for these uncertainties. Thus, despite the challenges in setting load limits for complex ecosystems, multiple lines of evidence helped derive robust nutrient load limits for managing the ICOLL to safeguard values associated with a healthy macrophyte community.

Community‐based monitoring of New Zealand stream macroinvertebrates: agreement between volunteer and professional assessments and performance of volunteer indices - R. G. Storey; A. Wright‐Stow (New Zealand Journal of Marine and Freshwater Research, 2017)
Community‐based monitoring of freshwaters (a form of citizen science) is an area of growing interest globally. It could be used to augment professional monitoring in New Zealand, as is done in other countries, if the agreement between volunteer and professional assessments is close enough. We compared volunteer benthic macroinvertebrate data with professional data from parallel monitoring over 18 months at 8 sites across New Zealand. We found strong correlations ( r =0.77–0.85) and little bias between volunteer data using volunteer indices and professional data using a professional index. Volunteer classifications in stream ‘quality classes' agreed with professional classifications in 70–85% of cases. Two volunteer‐level biotic indices showed slightly different correlation and bias with respect to the professional biotic index. A modified volunteer index could blend the strengths of each. Presence‐absence indices correlated as well as, or better than, their quantitative versions. We conclude that, given suitable training and support, volunteer assessments of stream ecological condition agree well with, and are only slightly more variable than, professional assessments.

Management and rehabilitation of aquatic ecosystems: introduction and synthesis - John M. Quinn; Malcolm O. Green; Marc Schallenberg; Roger G. Young; Chris C. Tanner; Andrew Swales (New Zealand Journal of Marine and Freshwater Research, 2017)

Dispersal distances of aquatic insects: upstream crawling by benthic EPT larvae and flight of adult Trichoptera along valley floors - S. Elizabeth Graham; Richard Storey; Brian Smith (New Zealand Journal of Marine and Freshwater Research, 2017)
Dispersal is an essential process which influences the effects of stream restoration on aquatic insect communities, yet dispersal capabilities of many New Zealand taxa remain unknown. We estimated realised dispersal distances of New Zealand Ephemeroptera, Plecoptera, and Trichoptera taxa by benthic crawling and of Trichoptera by aerial flight in intermittent streams, which are recolonised after every dry period. Benthic crawling distances were not more than 200 m for most genera. In contrast, adult caddisflies were found up to 1500 m from permanent water, with at least one family carrying eggs the full distance. This suggests greater potential for insects to recolonise distant restored sites by aerial dispersal than by crawling. Our results are a first step towards identifying the dispersal pathways used by desired colonist taxa and the distances over which they can disperse. This information will improve our ability to design and implement effective restoration.

Using environmental report cards to monitor implementation of iwi plans and strategies, including restoration plans - G. T. Tipa; E. K. Williams; C. Van Schravendijk‐Goodman; K. Nelson; W. R. K. Dalton; M. Home; B. Williamson; J. Quinn (New Zealand Journal of Marine and Freshwater Research, 2017)
Protecting valued attributes of a river’s socio‐ecological system demands a more holistic approach to freshwater management. Effective communication is critical to convey the breadth of values and the state of water systems to decision‐makers if they are to make meaningful decisions. Worldwide, environmental report cards are being used to define and measure progress towards environmental sustainability and promoted as an effective communication and engagement tool to galvanise commitment and action. This paper discusses the value of environmental report cards and contends that they can be a valuable integrative tool to support restoration strategies, as well as a way of conveying monitoring results to increase understanding about the health and well‐being of catchments. We present two case studies from the Waikato and Waitaki River in New Zealand where report cards based on eco‐cultural frameworks have been developed that explicitly link indicators that assess the state or condition of the catchment with the vision and goals articulated by iwi/hapū.

Oviposition site selectivity of some New Zealand aquatic macroinvertebrate taxa and implications for stream restoration - R. G. Storey; D. R. Reid; B. J. Smith (New Zealand Journal of Marine and Freshwater Research, 2017)
In many stream restoration projects, macroinvertebrates characteristic of natural conditions do not return despite habitat improvements. One contributing factor may be lack of oviposition sites for some taxa. To understand oviposition requirements of five taxa, we investigated their egg mass distributions on rocks in streams in the Waikato region, New Zealand. We compared insect taxa with aerial adults (caddisfly families Hydrobiosidae and Hydropsychidae, and blackfly species Austrosimulium australense and Austrosimulium sp.) to the fully aquatic limpet Latia neritoides . Egg masses of all taxa were highly aggregated, indicating strong site selection. Hydrobiosidae and both Austrosimulium species preferred ovipositing on emergent rather than submerged rocks. When ovipositing on submerged rocks, Hydropsychidae, Hydrobiosidae and A. australense preferred rocks Latia preferred large rocks (as did all taxa except Austrosimulium sp.) in reaches with low riparian shade. To allow recolonisation and/or persistence of these taxa, restored stream reaches need at least some rocks (or other features) with these characteristics.

Responses of stream macroinvertebrate communities and water quality of five dairy farming streams following adoption of mitigation practices - A. E. Wright‐Stow; R. J. Wilcock (New Zealand Journal of Marine and Freshwater Research, 2017)
Five streams in catchments with pastoral dairy farming as the dominant land use were monitored for periods up to 13 years after adoption of mitigation practices (MPs) to detect changes in stream macroinvertebrate communities and water quality. Water quality and macroinvertebrate community condition was degraded at the start with respect to N, P, suspended solids (SS), Escherichia coli concentrations, and a number of macroinvertebrate metrics, and were typical of catchments with intensive pastoral land use. Trend analysis showed a decrease in SS concentrations for all streams, generally increasing water clarity, and lower E. coli concentrations in two streams. The improvements, attributable to improved stream fencing and effluent disposal, were only sometimes associated with improved macroinvertebrate metrics, and suggest constraints of connectivity, habitat, time, and/or MP effectiveness. Macroinvertebrate species composition had the strongest correlation with total nitrogen at two sites, but changes probably reflected indirect factors associated with TN concentrations were responsible.

Corrigendum (New Zealand Journal of Marine and Freshwater Research, 2017)

Assessing mangrove clearance methods to minimise adverse impacts and maximise the potential to achieve restoration objectives - R. H. Bulmer; M. Lewis; E. O’Donnell; C. J. Lundquist (New Zealand Journal of Marine and Freshwater Research, 2017)
Management strategies in response to mangrove expansion in New Zealand include clearance, with the objective to restore the ecological and social values associated with sandflat habitats. However, it is unclear whether restoration of sandflats is achievable following mangrove clearance, or which methodologies minimise adverse impacts and maximise the potential to achieve restoration objectives. Four clearance sites were assessed for sediment characteristics and macrofaunal communities over 36 months following mangrove clearance to compare clearance methodology (hand or mechanically cleared), site characteristics (sheltered or exposed), size and shape. Hand clearances and sites exposed to greater hydrodynamic forces showed greatest transition to adjacent sandflat. However, our results suggest that transition to sandflat is unlikely within the first five years following mangrove clearance. This study fills gaps in science that are required to inform future mangrove clearance operations and monitoring, expectations of clearance outcomes and future management approaches.

Challenges for freshwater science in policy development: reflections from the science–policy interface in New Zealand - Helen L. Rouse; Ned Norton (New Zealand Journal of Marine and Freshwater Research, 2017)
Resolving challenges at the science–policy interface is key to improving the management of cumulative effects of pressures in catchments to meet societal goals for freshwater ecosystem health and water quality. This paper briefly reviews shifts in freshwater policy in New Zealand over the last six years, identifies implications for demands on science, and then offers a framework of topics to help guide freshwater scientists better help water resource managers both develop and implement policy. Key themes include: (i) being clear about the various potential roles of scientists and the particular importance of the ‘honest broker’ role at the interface; (ii) informing policy decisions on capacity for resource use, by predicting consequences of future scenarios; and (iii) integrating and communicating multidisciplinary technical and community‐derived knowledge, including handling inevitable uncertainty. Understanding and practising these topics will contribute to improved policy for managing cumulative effects and benefit New Zealand’s freshwaters and communities.

Seagrass rehabilitation: successful transplants and evaluation of methods at different spatial scales - F. E. Matheson; J. Reed; V. M. Dos Santos; G. Mackay; V. J. Cummings (New Zealand Journal of Marine and Freshwater Research, 2017)
Seagrass ( Zostera muelleri Irmisch ex. Aschers) was historically prolific in Whangarei Harbour, New Zealand, but has since declined. Over two years we compared the survival of mid‐intertidal zone transplants (18 × 0.25 m 2 plots) from a remnant meadow to a former site using three methods: (1) intact ‘sods’, (2) unanchored ‘sprigs’ and (3) sprigs amongst ‘mats’ of artificial plants. Before and after transplant, we quantified plant cover in all plots, and in transects across the wider intertidal zone. We also measured plant biomass, irradiance and water quality at each site. We found that sods and sprigs were equally effective with plant cover increased from −2 ). Donor plots regenerated within 9 months. This study shows that Z. muelleri can be rehabilitated by transplant upon reinstatement of suitable growing conditions at former sites.

Finding reference: a comparison of modelling approaches for predicting macroinvertebrate community index benchmarks - J. E. Clapcott; E. O. Goodwin; T. H. Snelder; K. J. Collier; M. W. Neale; S. Greenfield (New Zealand Journal of Marine and Freshwater Research, 2017)
Reference benchmarks are needed to assess the contemporary status of rivers and to establish restoration targets. We developed predictive models to estimate site‐specific reference values for a macroinvertebrate community index (MCI), which is used to indicate a range of human impacts on wadeable streams. We compared three statistical modelling approaches – general linear, boosted regression tree (BRT) and random forest (RF) – and tested the effect of spatial scale on predictive accuracy by developing national and regional BRT models. Using fitted flexible models (BRT, RF) and resetting predictors to reflect natural state provided the most accurate predictions of reference condition. Variation in reference MCI predictions from national and regional models was within the range observed from methodological and temporal variability. The proportion of native vegetation in upstream catchments was the primary predictor of MCI scores in all models, while secondary predictors varied regionally.

Issue Information (Reviews in Aquaculture, 2017)

Chinese Abstracts (Reviews in Aquaculture, 2017)

Effects of cryopreservation on mitochondria of fish spermatozoa - Elías Figueroa; Iván Valdebenito; Andrea B. Zepeda; Carolina A. Figueroa; Kelly Dumorné; Rodrigo L. Castillo; Jorge G. Farias (Reviews in Aquaculture, 2017)
The development of sperm cryopreservation has enabled transcendental changes to occur in the reproductive biotechnology of both mammals and fish; it has become a basic tool for animal improvement. Nevertheless, these protocols cause damage to cell structure and physiology, altering sperm functioning due to cryo‐injuries during freezing and thawing. However, studies of the effects on the structural, functional and genomic stability of the mitochondria in fish spermatozoa during cryopreservation are still lacking. The object of this review was to analyse the effect of cryopreservation on mitochondrial metabolic pathways in fish spermatozoa. This effect is related with the bioenergy mechanism for flagellar movement during the activation of sperm motility. In teleost fish, the mitochondria may be cylindrical, spherical or irregular in shape and adhere in a helicoidal or conical pattern to the middle piece. The salmonidae have only a single mitochondrion, but this may vary in other species; the mitochondria provide the flagellum with energy during sperm motility, when sperm respiration is essential. The effects of cryopreservation can induce structural damage to the mitochondria, altering the biochemical process involved in ATP production and thus causing a reduction in sperm motility. Fragmentation damage to nuclear DNA and diminution in sperm motility is mainly associated with damage to the structure and metabolic functioning of the mitochondrion. A direct correlation exists between the mitochondrial membrane potential (transmembrane integrity, ∆ Ψ m ) and the motility and fertilizing capacity of the cryopreserved spermatozoa, confirming that this organelle is the energy nucleus of the spermatozoon and that the cessation or prolongation of motility and successful fertilization depend on the availability of ATP in the spermatozoa. Further works are need to incorporate biotechnology studies, at cell and molecular level, of the possible effects of cryopreservation on mitochondrial DNA , enzymatic or metabolic modifications of the citric acid cycle, and the oxidative phosphorylation process in the inner membrane, as well as studies of the mitochondrial ultrastructure. Thus, mitochondrial dynamics could be established as a potential target for therapeutic strategies.

Physiological change and nutritional requirement of Pacific white shrimp Litopenaeus vannamei at low salinity - Erchao Li; Xiaodan Wang; Ke Chen; Chang Xu; Jian G. Qin; Liqiao Chen (Reviews in Aquaculture, 2017)
The Pacific white shrimp Litopenaeus vannamei is a euryhaline species with optimal salinity of 20–25 practical salinity unit (psu) for growth and survival, but has been cultured in inland water with salinity DHA and EPA from LNA at low ambient salinity, but further studies are needed to further confirm this finding. Future research should focus on the understanding of physiological mechanism and adaptation associated with salinity change and nutritional manipulation. The specific dietary requirements of essential fatty acids, essential amino acids, vitamins and minerals and the nutrition‐mediated immune response also warrant further study on shrimp at low salinity.

Circulation of water through a mussel raft: clearance area vs. idealized linear flows - Eva Aguiar; Silvia Piedracoba; Xosé Antón Álvarez‐Salgado; Uxío Labarta (Reviews in Aquaculture, 2017)
This study suggests revision of ecological concepts as food depletions and/or water flow reductions based on idealized linear flows through mussel rafts. We offer an alternative based on the extension of the clearance area, defined as the area affected by the nonlinear effects produced by each raft and surroundings ones. These conclusions are supported by our results, which indicate that (i) the preferential entry of water through a mussel raft does not occur through the bow, contrary to previously thought, and (ii) the intraraft circulation is strongly influenced by the orientation of the raft relative to the background current direction and does not follow a defined pattern. Intraraft circulation is assessed by means of four current metres installed at each side of the raft and the dimensions of the clearance area using long‐term data provided by GPS and compass. While both intraraft circulation and clearance area dimensions are mainly controlled by tide, the net water exchange through the raft is reasonably explained by wind (velocity and direction) and river discharges.

Penaeid shrimp cell culture and its applications - Jie Ma; Lingbing Zeng; Yuanan Lu (Reviews in Aquaculture, 2017)
The aquaculture of penaeid shrimp has grown rapidly during the past three decades. However, shrimp aquaculture continues to be plagued by infectious disease, particularly of viral aetiology. Urgently needed are in vitro biological tools to facilitate early detection and diagnosis of penaeid shrimp viruses. An immediate need is the establishment of stable or continuous shrimp cell lines, which remains to be an elusive goal. Researchers have made significant advancements in the methodologies for primary shrimp cell culture. Also, new media and technologies including cell immortalization are presently under development. The principal goal of this review paper is to collate current attempts in the establishment of permanent shrimp cell lines by summarizing the latest research progress on penaeid shrimp cell culture studies, including general cultivation conditions, methods of cell preparation, types of media and their utilization and the development of immortal cell lines. In addition, current and potential applications of penaeid shrimp cell cultures in the various related research fields are also discussed in this review.

Coping styles in farmed fish: consequences for aquaculture - Maria Filipa Castanheira; Luís E.C. Conceição; Sandie Millot; Sonia Rey; Marie‐Laure Bégout; Børge Damsgård; Tore Kristiansen; Erik Höglund; Øyvind Øverli; Catarina I.M. Martins (Reviews in Aquaculture, 2017)
Individual differences in physiological and behavioural responses to stressors are increasingly recognised as adaptive variation and thus raw material for evolution and fish farming improvements including selective breeding. Such individual variation has been evolutionarily conserved and is present in all vertebrate taxa including fish. In farmed animals, the interest in consistent trait associations, that is coping styles, has increased dramatically over the last years because many studies have demonstrated links to performance traits, health and disease susceptibility and welfare. This study will review (i) the main behavioural, neuroendocrine, cognitive and emotional differences between reactive and proactive coping styles in farmed fish; (ii) the methodological approaches used to identify coping styles in farmed fish, including individual (group) mass‐screening tests; and (iii) how knowledge on coping styles may contribute to improved sustainability of the aquaculture industry, including welfare and performance of farmed fish. Moreover, we will suggest areas for future research, where genetic basis (heritability/epigenetic) of coping styles, and the neuroendocrine mechanisms behind consistent as well as flexible behavioural patterns are pinpointed as central themes. In addition, the ontogeny of coping styles and the influence of age, social context and environmental change in coping styles will also be discussed.

Microbial metagenomics in aquaculture: a potential tool for a deeper insight into the activity - Marcel Martínez‐Porchas; Francisco Vargas‐Albores (Reviews in Aquaculture, 2017)
The use and study of microbes in aquaculture has become a common practice in the last decade. Metagenomics is a relative recent genomics subdiscipline that has emerged as a promising scientific tool to analyse the complex genomes contained within microbial communities. However, despite the potential of metagenomics, its use is not yet common in some agro‐industrial disciplines such as aquaculture. In this review, we analyse some of the potential uses of metagenomics in aquaculture to highlight the microbial diversity and dynamics of the culture systems. This review addresses some potential uses of metagenomics in the study of microbial diversity, microbial roles in microcosms, antibiotic resistance genes, novel and potential pathogens, microbial communities forming bioflocs, probiotics and other applications.

Development of passive sampling devices for bioavailable contaminants of current and emerging concern: Waitemata Harbour case study - M Stewart; M Cameron; M McMurtry; SG Sander; B Benedict; L Graham; M Hosie; T Green (New Zealand Journal of Marine and Freshwater Research, 2016)
Bioavailable contaminant concentrations are an important component in assessing environmental effects as they directly affect ecosystem health. Shellfish contaminant monitoring programmes have traditionally filled this requirement but are being phased out in some jurisdictions. Passive sampling devices (PSDs) have the potential to replace shellfish monitoring; however, there are still knowledge gaps to address before this can occur. This study assessed the suitability of three different PSDs in providing the required information to replace shellfish monitoring. PSDs were deployed at three historic mussel monitoring sites with different levels of urban influence in the Waitemata Harbour, Auckland, New Zealand. Contaminants of interest were urban heavy metals, plus current and emerging organic contaminants. PSDs provided extremely low detection limits and, for some contaminants, very strong correlations to shellfish. PSDs can currently complement shellfish in monitoring, but it is premature to make conclusions as to the suitability of PSDs in replacing shellfish monitoring until more information is available.

Remediation of a major acid mine drainage point source discharge restores headwater connectivity for a diadromous native fish - DP Gray; JS Harding; P Lindsay (New Zealand Journal of Marine and Freshwater Research, 2016)
Rivers receiving acid mine drainage (AMD) are frequently depauperate in fish and impacts may extend long distances downstream. AMD inputs may form chemical barriers for migratory species and isolate fish in unimpacted headwaters. We investigated the response of a diadromous fish, kōaro ( Galaxias brevipinnis ), to remediation of an AMD tributary in a 5th order river in New Zealand. A 2005 survey indicated limited recruitment of kōaro in the river likely due to the chemical barrier of AMD. By 2010, water treatment in the contaminated tributary had raised pH from a median value of 4.3 to 6 and reduced metals in the lower river, notably aluminium from a median of 2.48 to 0.41 mg/L. In 2012, kōaro density had increased by an order of magnitude relative to 2005. Furthermore, a greater proportion of juvenile fish were present. These results indicate that large‐scale remediation of discharges can reverse the impacts of AMD on fish migration.

Movements in the harlequin fish ( Othos dentex ), a large predatory serranid from southern Australia: implications for detection and protection - S Bryars; PJ Rogers (New Zealand Journal of Marine and Freshwater Research, 2016)
The harlequin fish ( Othos dentex ) is the largest serranid found in the temperate waters of southern Australia. Acoustic telemetry was used to continuously track the movements and activity patterns of 10 harlequin fish (330–620 mm total length; 0.5–3 kg weight) for a 16‐month period at a coastal reef site. Data showed that the harlequin fish is a site‐attached, diurnal predator, with a relatively small home range in comparison with other temperate reef fishes from Australia and New Zealand. These characteristics indicate that the harlequin fish is susceptible to localised depletions from fishing, but that it can be protected within no‐take marine protected areas and can be detected with appropriate daytime monitoring techniques. Individuals also displayed discrete depth preferences on the reef slope, evidence of a nocturnal home base, and homing ability following disturbance from an extreme storm event.

Editorial Board (New Zealand Journal of Marine and Freshwater Research, 2016)

Distribution, habitat and movement of juvenile smooth hammerhead sharks ( Sphyrna zygaena ) in northern New Zealand - MP Francis (New Zealand Journal of Marine and Freshwater Research, 2016)
The smooth hammerhead shark, Sphyrna zygaena , occurs in warm temperate waters around the northern North Island of New Zealand. Commercial fishing records and research trawl survey data were used to determine their distribution. Highest catch rates were recorded in relatively sheltered bays and coastlines along the northeast coast of North Island. Neonate and juvenile sharks use shallow coastal waters and large harbours and estuaries as nursery areas up to an age of two years and total length of 150 cm. Five sharks were electronically tagged but two apparently died and three (137–160 cm total length) returned useful data. Two tagged sharks remained in or near the Bay of Islands for 6–55 days after tagging, moving extensively through the bay. A third shark moved about 155 km southeast in 250 days. That shark spent 70 days mostly shallower than 10 m (94% of time) with occasional dives to 40 m. Thereafter, it oscillated between the surface and depths of 60−80 m, with most time (55%) being spent at 40−60 m. Maximum recorded depth was 144 m.

Riparian management affects instream habitat condition in a dairy stream catchment - R Holmes; J Hayes; C Matthaei; G Closs; M Williams; E Goodwin (New Zealand Journal of Marine and Freshwater Research, 2016)
Using a space‐for‐time substitution design, we investigated the response of structural instream habitat and fish populations to different riparian management practices throughout a Dairy Best Practice Catchment. We found a significant negative correlation between the upstream area of stock exclusion fencing and deposited instream fine sediment cover. Furthermore, we determined that this relationship emerges when ≥300 m lengths of upstream riparian area were included in the analysis, indicating the scale at which stock exclusion fencing results in a positive instream habitat response. Specifically, for this historically degraded spring‐fed stream, our findings indicate that riparian segments with 5 m wide stock exclusion fences (both banks) are required to achieve instream fine sediment cover below 20% in downstream reaches. Fish were sparse and evenly spread throughout the catchment. Fish distributions were not correlated with reach‐scale riparian or instream habitat variables, possibly because the available habitat quality gradient was too narrow.

Turbulent mixing in a stratified estuarine tidal channel: Hikapu Reach, Pelorus Sound, New Zealand - CL Stevens; MJ Smith (New Zealand Journal of Marine and Freshwater Research, 2016)
Channel constrictions within an estuary can influence overall estuary‐sea exchange of salt or suspended/dissolved material. The exchange is modulated by turbulent mixing through its effect on density stratification. Here we quantify turbulent mixing in Hikapu Reach, an estuarine channel in the Marlborough Sounds, New Zealand. The focus is on a period of relatively low freshwater input but where density stratification still persists throughout the tidal cycle, although the strength of stratification and its vertical structure vary substantially. The density stratification increases through the ebb tide, and decreases through the flood tide. During the spring tides observed here, ebb tidal flow speeds reached 0.7 m s −1 and the buoyancy frequency squared was in the range 10 −5 to 10 −3 s −2 . Turbulence parameters were estimated using both shear microstructure and velocimeter‐derived inertial dissipation which compared favourably. The rate of dissipation of turbulent kinetic energy reached 1 × 10 −6 m 2 s −3 late in the ebb tide, and estimates of the gradient Richardson number (the ratio of stability to shear) fell as low as 0.1 (i.e. unstable) although the results show that bottom‐boundary driven turbulence can dominate for periods. The implication, based on scaling, is that the mixing within the channel does not homogenise the water column within a tidal cycle. Scaling, developed to characterise the tidal advection relative to the channel length, shows how riverine‐driven buoyancy fluxes can pass through the tidal channel section and the stratification can remain partially intact.

The spatio‐temporal distribution and population structure of green turtles ( Chelonia mydas ) in New Zealand - DA Godoy; ANH Smith; C Limpus; KA Stockin (New Zealand Journal of Marine and Freshwater Research, 2016)
Despite being endangered internationally and protected nationally, little consideration has been given to the occurrence of green turtles ( Chelonia mydas ) in New Zealand. New Zealand lies on the southern boundary of the distributional range of green turtles in the southwestern Pacific, with individuals found within these waters historically considered to be occasional visitors or stragglers incidentally carried by ocean currents. However, the present work shows that green turtles are present year round in New Zealand’s northern waters (c. 34°–38° S). A review of sighting, stranding and incidental capture data collected between 1895 and 2013 illustrate New Zealand’s green turtle population comprises post‐pelagic immature juveniles to large subadults. The female:male sex ratio of 1.7:1 is similar to those reported from warm temperate foraging grounds in eastern Australia. A subsample of new recruits indicates green turtles recruit to neritic habitats at approximately 40.8 cm curved carapace length. This study suggests that New Zealand’s neritic habitats constitute a transitional developmental ground for post‐pelagic immature green turtles. We observed an exponential increase in the number of documented records over time, though whether this is due to increased numbers of turtles or increased reporting rates, or both, is unclear and warrants further investigation. More broadly, this work provides a baseline understanding of the ecology of green turtles at the edge of their range, providing opportunities to investigate regional niche modelling and connectivity of this highly mobile species, while also monitoring broad‐scale effects of climate‐induced environmental change.

Chinese Abstracts (Reviews in Aquaculture, 2016)

Issue Information (Reviews in Aquaculture, 2016)

Enhancing aquaculture development: mapping the tilapia aquaculture value chain in G hana - Berchie Asiedu; Pierre Failler; Yolaine Beyens (Reviews in Aquaculture, 2016)
Fish is important in the diet of millions of Ghanaians supplying protein and micronutrients. Ghanaians have developed taste preferences for the consumption of O reochromis niloticus (Nile tilapia), thereby booming the tilapia aquaculture industry. This paper looks comprehensively at the value chain of the tilapia aquaculture sector in Ghana to identify particular areas of intervention and development opportunities in achieving food security and nutrition needs, safety, quality and trade benefits. Mixed methods (including stakeholders’ workshop, interviews and document analysis from official sources) were employed in collecting data between January and December 2014. The analysis indicates that farmed tilapia products are currently not exported but locally consumed. In 2012, approximately 28 000 t of tilapia were supplied to the local market. The bulk of the supply came from cage culture (85%) with the remaining coming from ponds and dugouts. About 98% of tilapia coming from aquaculture is supplied directly to the local markets, whilst 2% is family consumed (subsistence). The marketing channel involves farmers selling to wholesalers/retailers and to consumers/restaurants in nearby villages or secondary towns. The processing technology is generally low (mainly sun drying, small size smokers). Currently, due to the growing middle‐class Ghanaians, high domestic demand for fish and high levels of undernutrition among many poor Ghanaians, there is a good and readily available market for all sizes of tilapia produced locally. However, farmed tilapia has the potential for export to the international markets if it is processed as smoked and salted. To achieve this, there is the need to develop a practical guide for aquaculture exporters by the relevant stakeholders, strengthen capacity building of public institutions to deal with the export of aquaculture products and train more aquaculture personnel, and collate proper documentation of aquaculture products.

Disinfection of teleost eggs: a review - Evelien De Swaef; Wim Van den Broeck; Kristof Dierckens; Annemie Decostere (Reviews in Aquaculture, 2016)
In aquaculture hatcheries, egg disinfection is commonly employed as a mortality mitigation and disease management tool. In addition, disinfection protocols are utilized in research facilities, as a means to create axenic and gnotobiotic larval models. For the latter, a complete sterilization of the eggs is warranted. Multiple research groups have tested various disinfectants in fish eggs adopting different protocols and a range of parameters to evaluate their efficacy and safety. However, there is a clear lack of a critical review listing these different studies and stressing the advantages and shortcomings of the protocols and adopted disinfectants. This review provides a commented survey of the findings/experiments on the most frequently used and upcoming disinfecting products, the protocols in which they are included and their purposes with emphasis on decreasing bacterial and/or fungal load, underscoring the benefits and the limitations of each product. Supplemented with a critical note, this review assists both aquaculturists and researchers in making an informed choice. Moreover, it will help stakeholders to identify the gaps in knowledge where future research on egg disinfection is needed.

A review of genotype‐by‐environment interaction and micro‐environmental sensitivity in aquaculture species - Panya Sae‐Lim; Bjarne Gjerde; Hanne Marie Nielsen; Han Mulder; Antti Kause (Reviews in Aquaculture, 2016)
Generating breeding programmes that effectively improve farmed fish performance across multiple environments and make fish more uniform within production environments would aid farmers to produce food under diverse environments. We review genotype‐by‐environment interaction leading to re‐ranking of genotypes across environments, that is non‐unity genetic correlation between traits measured in different environments, and micro‐environmental sensitivity leading to a change in environmental variance of a trait. A quantitative review across 38 species showed that (i) genotype‐by‐environment interaction studies are lacking for many economically important traits. (ii) Re‐ranking is moderate for growth (average genetic correlation = 0.72) and survival (average genetic correlation = 0.54). Significant re‐ranking is of concern because selection in a nucleus leads to lower genetic responses in commercial environments compared to a case when re‐ranking does not exist. (iii) Re‐ranking is weak for age‐at‐sexual‐maturity and fish appearance (average genetic correlation = 0.86), implying that genetic improvement in one environment is expected to be effective in the other environments. Future research should provide guidelines for how to account for genotype‐by‐environment interaction when collecting data, estimating breeding values and optimising the structure of the breeding programme. (iv) Coefficient of genetic variation for sensitivity against unknown micro‐environmental factors within a single environment for body weight is high. Hence, genetic improvement towards less sensitive fish, resulting in more uniform production, is possible, but a large number of relatives with phenotypes is needed for obtaining moderate accuracy of selection. This review elucidates needs for further research on genotype‐by‐environment interaction and micro‐environmental sensitivity in economically important traits and species.

Effects of environmental and farm stress on abalone physiology: perspectives for abalone aquaculture in the face of global climate change - Andrea J. Morash; Katharina Alter (Reviews in Aquaculture, 2016)
Many abalone farms are reliant on coastal water inputs which are subject to fluctuations in environmental variables such as temperature, oxygen, CO 2 and salinity. Near future climate change scenarios predict that there will be more frequent extreme weather events which can exacerbate these fluctuations and potentially be deleterious to farmed abalone where these variables remain largely uncontrolled. In this review, we have taken an in depth examination of current literature on the effects of environmental stress on abalone physiology and metabolism and how this affects their health and growth. In conjunction, we have also reviewed the effects of farm‐specific stressors such as ammonia, stocking density, handling, nutrition and disease and the synergistic effects of these and environmental stressors on abalone physiology. We have identified currents gaps in our knowledge of this under‐studied species and have made predictions on the effects of climate change on future abalone production with suggestions for future research. In summary, it is expected that abalone will show reduced growth rates as more energy is invested in combating stresses rather than growth. Furthermore, disease outbreaks may become more frequent with greater fluctuations in temperature and salinity, both of which have large‐scale effects on immunity. The current body of knowledge is mainly on whole animal effects of stresses, but we know very little of their mechanistic foundation. Research in this area as well as investments in infrastructure will be pivotal in identifying and implementing strategic interventions to maintain a sustainable abalone industry in Australia.

The fishes of New Zealand, edited by Clive DRoberts, Andrew LStewart and Carl DStruthers, Wellington, Te Papa Press, 2015, 4 volumes, 2008 pp, NZ$250.00 (hardback), ISBN: 9780994104168 - Malcolm Francis (New Zealand Journal of Marine and Freshwater Research, 2016)

Water quality in New Zealand rivers: current state and trends - ST Larned; T Snelder; MJ Unwin; GB McBride (New Zealand Journal of Marine and Freshwater Research, 2016)
River water quality, particularly in lowland catchments, is a matter of concern to the New Zealand public. We assessed river water quality and biological state and trends using data from more than 900 monitoring sites. Parallel state and trend analyses were carried out using all sites and a subset of lowland river sites. Median water‐quality state in urban and pastoral land‐cover classes was poorer than in exotic forest and natural land‐cover classes, and lowland sites in the urban and pastoral classes had the poorest water quality. Nutrient and Escherichia coli concentrations increased and visual clarity and Macroinvertebrate Community Index scores decreased as proportions of catchments in high‐intensity agricultural and urban land cover increased. Ten‐year trends (2004–2013) indicated recent improvements in ammoniacal nitrogen, dissolved reactive phosphorus and total phosphorus in the pastoral and urban classes, possibly reflecting improved land management. In contrast, trends in nitrate‐nitrogen in the exotic forest and cool‐dry/pastoral classes indicated worsening conditions.

Distribution and relative density of cetaceans in the Hauraki Gulf, New Zealand - SL Dwyer; DM Clement; MDM Pawley; KA Stockin (New Zealand Journal of Marine and Freshwater Research, 2016)
Understanding species distributions, and how they change in space and time, is vital when prioritising conservation or management initiatives. We assessed the distribution and density patterns of common dolphins ( Delphinus sp.), bottlenose dolphins ( Tursiops truncatus ) and Bryde’s whales ( Balaenoptera edeni ) in the Hauraki Gulf, New Zealand. Dedicated boat‐based surveys were conducted in the inner Hauraki Gulf (IHG) and off Great Barrier Island (GBI) during 2010–2012. Generalised linear models were used to investigate temporal changes in relative densities and kernel density estimation was implemented to examine spatial trends. Common dolphins were widely distributed during all seasons, with higher densities observed during winter and spring in the IHG but during autumn off GBI. There was inter‐annual variation in Bryde’s whale distribution, with high densities recorded off GBI in 2011. Bottlenose dolphins were infrequently sighted in the IHG but regularly encountered off GBI, with the highest densities during spring and summer.

Erratum (New Zealand Journal of Marine and Freshwater Research, 2016)

Setting quotas using provisional data: a case study from the South Australian abalone fisheries - J Dent; S Mayfield; B Stobart; J Carroll (New Zealand Journal of Marine and Freshwater Research, 2016)
Stock assessments of quota or effort managed fisheries in which the duration of the fishing season is 12 months are invariably delivered well into the subsequent fishing season. As a result, quotas are frequently based on year‐old data. This delay is often unavoidable because it may take months to collect, collate and analyse data necessary to assess fishery performance. The South Australian fisheries for blacklip ( Haliotis rubra Leach, 1814) and greenlip abalone ( H. laevigata Donovan, 1808) have addressed this issue by using provisional data on current stock status to inform application of the harvest strategy decision rules that set the quota for the next year. The primary index of relative abundance for these fisheries is catch per unit effort (CPUE). Our study uses 25 years (1988–2012) of CPUE data to quantify the differences between the provisional and complete‐season CPUE estimates at the spatial scales used to assess the fisheries. We demonstrate that, in most cases, there was a strong relationship between the provisional and complete‐season CPUE estimates for both species, with little evidence of bias. As the provisional CPUE estimates were a reliable and accurate predictor of the complete‐season CPUE estimates, this provides a high degree of confidence in using provisional CPUE estimates to set quotas, thereby overcoming the difficulty of basing decisions on aged data. These findings are likely to be applicable to other fisheries, particularly those where much of the annual catch is obtained (or effort expended) in a short time period at the commencement of the fishing season.

Do predatory fish of benthic crustaceans vary between kelp and barren reef habitats in northeastern New Zealand? - J Hesse; JA Stanley; AG Jeffs (New Zealand Journal of Marine and Freshwater Research, 2016)
Fish assemblages that included known predators of benthic crustaceans were compared between kelp and barren habitats in northeastern New Zealand using baited underwater video census methods. The benthic‐feeding fish were observed in winter, spring/summer and autumn, as well as during night‐time in spring/summer. Overall, the fish assemblages varied between barren and kelp habitat, being most marked in winter. Individual benthic‐feeding species, such as grey mao mao ( Scorpis lineolatus ) and leatherjacket ( Meuschenia scaber ) were associated with barren habitat, while the spotted wrasse ( Notolabrus celidotus ) was more strongly associated with kelp habitat. The results suggest that changes in habitats on coastal reefs affect populations of species that are benthic predators, which may in turn influence the distribution and abundance of their prey species, such as juvenile spiny lobsters.

Body and brood sizes of Tenagomysis spp. (Crustacea: Mysida) in southern estuaries in New Zealand - S Paul; DM May; M Lee; GP Closs (New Zealand Journal of Marine and Freshwater Research, 2016)
Mysids form a large biomass and mediate the benthic–pelagic coupling of numerous estuaries in southern New Zealand. An intra‐annual (2011–2012) field survey in the breeding seasons (i.e. austral spring followed by summer) of mysids Tenagomysis chiltoni and Tenagomysis novaezealandiae , examining the body and brood sizes, was conducted. Samples were collected from six open and eight intermittently open/closed estuaries along the Otago coastline. Brood size of gravid females of T. chiltoni was not significantly related to their body size. Brood size of gravid females of T. novaezealandiae showed a significantly positive relationship with body size in spring but not in summer. It appears that brood size of gravid mysids do not always necessarily depend on body size, but may be influenced by breeding season (e.g. spring) and estuarine typology (e.g. intermittently open/closed).