Daniel Oesterwind results 28
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Oceanographic parameters associated with spatial occurrence of cephalopods in standardized demersal fishing trawls in the NE AtlanticNARA Subscribed
In this work, the environmental occurrence ranges of different European cephalopod species are described for the whole NE Atlantic shelf including the greater North Sea and Baltic Sea. This is done based on the environmental parameters collected in-situ during surveys that caught commercially important cephalopod species (1990–2022). Results are supplemented and compared with information available in the published literature a...
Classification of European Illex coindetii and Loligo forbesii Squid Stocks by Trace Element Analysis of StatolithsNARA Subscribed
We investigated whether statolith microchemistry analysis could classify ommastrephid and loliginid squid species into fishery stocks. Statolith nucleus (early life stage) and edge (life stage at time before catch) of Illex coindetii (Verany, 1839) and Loligo forbesii (Steenstrup, 1856) from various areas of the North East Atlantic Ocean and Mediterranean Sea during 2021–2022 were analysed using laser ablation ICP‐MS to measur...
Squids occur worldwide in marine ecosystems and play a major role in pelagic food webs by connecting lower and higher trophic levels. Their high feeding intensities and pronounced diel vertical migrations make squids important components of nutrient cycles in marine ecosystems. This study assessed the trophic position and nutritional ecology of a squid species assemblage in the Benguela Upwelling System (BUS) by combining stom...
Non-indigenous species (NIS) are on a rise globally. They can pose strong impacts on ecosystems in their non-native range and can therefore be a serious threat to biodiversity. Here, we compile the existing information available regarding the extent to which commercially and recreationally used fish stocks (exploited fish species) are affected by NIS. To do so, we conducted a literature review to summarize the known and presum...
Stock discrimination of two European squids ( Illex coindetii , Loligo forbesii ) by statolith shape analysisNARA Subscribed
We evaluated the feasibility of classifying ommastrephid and loliginid squid species by statolith shape analysis into fisheries management units or stocks. Statoliths of Illex coindetii (Verany, 1839) and Loligo forbesii (Steenstrup, 1856) were studied from multiple areas of the North East Atlantic and Northern Mediterranean Sea during 2021–2022. I. coindetii and L. forbesii individuals were categorized into multiple stocks ac...
Scientific monitoring is a fundamental basis of scientific advice. Among others, monitoring aims at contributing towards understanding the influence of anthropogenic use (e.g. fisheries), the health of a stock and individuum and effectiveness of management and conservation measures (e.g. MPAs). Monitoring of demersal and benthic fish communities is often based on invasive methods like bottom trawling, however in some cases les...
Trophic ecology and seasonal occurrence of two Red List fish species in the Western Baltic Sea—two of a kind?NARA Subscribed
Improving the conservation status and the management of Red List species requires knowledge on the biology and distribution of the organisms as well as an evaluation of the appropriateness of management measures. This study provides information on the trophic ecology and seasonal abundances of two Red List fish species from the Western Baltic Sea, snake blenny Lumpenus lampretaeformis (Walbaum, 1792), classified as “critically...
Stomach content analysis of North Sea cephalopods: often-overlooked predators with direct impact on commercially used fish species?NARA Subscribed
The study of marine food web models has increased during the last years, but input data of important groups such as cephalopods are missing sometimes which restricts the quality of the model results. Cephalopods feed on a variety of preys, ranging from small crustaceans to large commercially important fish species. In turn, they are taken by larger invertebrates, fish, cephalopods, marine mammals and seabirds, which emphasizes...
Bottom trawling is one of the main pressures on benthic ecosystems, directly impacting the targeted species and physically disturbing the seabed and the benthic invertebrate communities, in turn indirectly impacting benthivorous fish and the entire benthic food web structure and functioning. To predict the cascading effect of bottom trawling on benthic and demersal fish communities, it is crucial to understand the trophic inte...
Despite being landed in commercial cephalopod fisheries, species of Alloteuthis are not yet well defined, with A. subulata and A. media often confused. DNA barcoding combined with morphometric analyses has begun to clarify the distinction between these two morphologically similar species but has been limited in its geographic coverage to date. Herein, we provide DNA barcodes for 228 specimens collected from Guinea Bissau in th...
Cephalopods, a gap in the European Marine Strategy Framework Directive and their future integrationNARA Subscribed
With the aim of maintaining or obtaining good environmental status in the Northeast Atlantic and northern Mediterranean Sea, the European Marine Strategy Framework Directive (EU-MSFD) came into force in 2008. All EU Member States (MS) have the task of assessing the current state of their adjacent waters to guarantee sustainable use of marine resources and healthy ecosystems for the current and future generations. Although the...
Climate change-related changes in cephalopod biodiversity on the North East Atlantic ShelfNARA Subscribed
Global studies imply that cephalopods have benefited from climate change. However, in most areas, species-specific long-term cephalopod data sets do not exist to support this implication and to analyse the response of cephalopods to environmental changes. Our results illustrate that historical studies, in combination with recent data sets, can fill this gap, enabling descriptions of ecological changes over a long time. We show...
Native to the Ponto-Caspian region, the benthic round goby ( Neogobius melanostomus ) has invaded several European inland waterbodies as well as the North American Great Lakes and the Baltic Sea. The species is capable of reaching very high densities in the invaded ecosystems, with not only evidence for significant food-web effects on the native biota and habitats, but also negative implications to coastal fishers. Although ge...
Marine protected areas (MPAs) are designated parts of the ocean that restrict human activities to a certain degree. MPAs are established around the world using a wide range of legislative instruments and thus come in a variety of forms and shapes. Despite being regarded as the “cornerstone” of global marine conservation efforts, they currently cover less than 10% of the ocean surface. Individual MPAs aim to achieve goals rangi...
Habitat utilization and feeding ecology of small round goby in a shallow brackish lagoonNARA Subscribed
We examined small-scale distribution and feeding ecology of a non-native fish species, round goby ( Neogobius melanostomus (Pallas, 1814)), in different habitats of a coastal lagoon situated in the south-western Baltic Sea. First observations of round goby in this lagoon were reported in 2011, 3 years before the current study was conducted, and information on this species’ basic ecology in different habitats is limited. We fou...
Electronic monitoring in fisheries: Lessons from global experiences and future opportunitiesNARA Subscribed
Since the beginning of the 21st century, electronic monitoring (EM) has emerged as a cost‐efficient supplement to existing catch monitoring programmes in fisheries. An EM system consists of various activity sensors and cameras positioned on vessels to remotely record fishing activity and catches. The first objective of this review was to describe the state of play of EM in fisheries worldwide and to present the insights gained...