ICES Journal of Marine Science: Journal du Conseil

Brusca, Richard C

doi: 10.1093/icesjms/fsae013pmid: N/A

Changes and needs in marine science (and natural science in general) training over the past six decades are discussed. Among these are: new technological advances; the loss of -ology courses; the loss of field courses and sense of place opportunities for students; the need for a more interdisciplinary approach to training natural science students; a need to better expose our students to threats to Earth’s biocultural diversity; a need to include more humanities in our student training, including addressing diminished readership and appreciation of the great books; the nature of creativity; the perils of the internet; and university emphasis on faculty overhead dollars and high-profile publications at the expense of student training and more creative research.

Vigo, Maria; Galimany, Eve; Poch, Patricia; Santos-Bethencourt, Ricardo; Sala-Coromina, Joan; Bahamón, Nixon; Aguzzi, Jacopo; Navarro, Joan; Company, Joan B

doi: 10.1093/icesjms/fsae003pmid: N/A

The Norway lobster, Nephrops norvegicus, is one of the most valuable fishery resources in many coastal countries of the Mediterranean Sea and the northeastern Atlantic Ocean. In the Mediterranean Sea, several stocks are being overexploited, with ecological, economic, and social consequences. To perform an adequate stock assessment and provide guidance on maximum sustainable yield, reliable biological parameters of the species are required. Considering that biological parameters may change over time in overexploited populations, in the present study, we updated key biological parameters for the N. norvegicus stock of the northwestern Mediterranean Sea: size at which 50% (L50) of females were in reproductive condition, length–weight relationship, and individual size structure. Moreover, daily landings were combined with the spatial position of the vessels tracked by their Vessel Monitoring System (VMS), to obtain information on the geographical distribution and time series of Landings Per Unit Effort (LPUE), as well as total landings from 2008 to 2021. Our results suggest overexploitation of the resource, revealing a severe reduction in size at 50% maturity, an earlier spawning and brooding period, and a clear decrease of LPUE over time.

Ouyang, Wenjia; Wei, Yanhui; Hou, Tongtong; Liu, Junnan

doi: 10.1093/icesjms/fsae004pmid: N/A

With the assistance of the visual system, remote operated vehicles (ROVs) can replace frogmen to achieve safer and more efficient capturing of marine organisms. However, the selective absorption and scattering of light lead to a decrease in the visual quality of underwater images, which hinders ROV operators from observing the operating environment. Unfortunately, most image enhancement methods only focus on image color correction rather than perceptual enhancement, which in turn prevents the object detector from quickly locating the target. Therefore, a visual-enhanced and detection-friendly underwater image enhancement method is needed. In this paper, an underwater image enhancement method called in-situ enhancement is proposed to improve the semantic information of the visual hierarchy based on current scene information in multiple stages. Mapping the underwater image to its dual space allows the enhancement equation to be applied to severely degraded underwater scenes. Moreover, it is also a detection-friendly method and has good generalization in both visual quality improvement and object detection. The experimental results show that in different underwater datasets, the in-situ enhancement effectively improves the visual quality of underwater images, and its enhanced results train different object detectors with high detection accuracy.

Galparsoro, Ibon; Pouso, Sarai; García-Barón, Isabel; Mugerza, Estanis; Mateo, María; Paradinas, Iosu; Louzao, Maite; Borja, Ángel; Mandiola, Gotzon; Murillas, Arantza

doi: 10.1093/icesjms/fsae006pmid: N/A

Effective and sustainable management of small-scale fisheries (SSF) is challenging. We describe a novel approach to identify important fishing grounds for SSF, by implementing a habitat modelling approach, using environmental predictors and Automatic Identification System (AIS)-B data coupled with logbook and First Sales Notes data, within the SE Bay of Biscay. Fishing activity patterns and catches of longliners and netters are used to determine the main environmental characteristics of the fishing grounds, and a habitat modelling approach is implemented to predict the zones that fulfil similar environmental characteristics across a larger geographical extent. Generalized additive mixed models (GAMMs) were built for 24 fish species, and to identify other zones that fulfil similar characteristics and, thus, could be considered relevant for the species targeted by each gear type. Most of the models showed a good prediction capacity. The models included between one and four predictor variables. ‘Depth of mixing layer’ and ‘benthic rocky habitat’ were the variables included more frequently for fish species captured by netter’s fleet. For longliners, the ‘seafloor slope’ and ‘benthic rocky habitat’ were the two most important variables. The predictive maps provide relevant information to assist in management and marine spatial planning.

Batsleer, Jurgen; Griffiths, Christopher A; Bleeker, Katinka; Johnston, Graham; Cardinale, Massimiliano; Lorance, Pascal

doi: 10.1093/icesjms/fsae008pmid: N/A

The International Council for the Exploration of the Sea (ICES) typically provides advice on fishing opportunities on a stock-by-stock basis. Nevertheless, levels of total allowable catch (TAC) are sometimes set for a collection of stocks and species (i.e. a common TAC). An explicit expectation of these is that landings will scale with ICES advice, especially when ICES advice is used to calculate the common TAC. This expectation is tested for skates and rays in the Northeast Atlantic, spanning 26 stocks, 8 species, and 3 ecoregions. Using ICES landings and ICES advice data from 2016 to 2022, we show that landings of several stocks and species have overshot their respective ICES advice, whereas others have undershot. Specifically, some stocks of blonde ray (Raja brachyura) in North Sea and Celtic Seas ecoregions are being landed at a rate that often exceeds double its ICES advice. By collating species based on their ICES assessment category and life-history traits, we find that those considered data-poor and potentially most vulnerable to fishing are consistently landed at higher-than-expected rates in the Celtic Seas. This study questions the appropriateness of a common TAC for skates and rays and calls for shifts towards the use of single-stock catch allocations and the application of advanced stock assessment methodologies.

White, Shelby B; Scheld, Andrew M

doi: 10.1093/icesjms/fsae010pmid: N/A

Diversification within and outside of small-scale fisheries (SSF) is a common strategy to stabilize revenues and increase resilience following disturbances. Using SSF in Virginia, USA as a case study, Herfindahl–Hirschman Indices (HHIs) were used to characterize individual and fleet levels of income diversification, while generalized linear mixed models were used to examine drivers of diversification behavior. HHI income values indicate that fishers tended to exhibit specialized behavior. More diversified fishers tended to have less interannual revenue variability and higher annual incomes. Decisions to increase or decrease diversification were associated with various factors, including total years of participation, annual income, the type of licenses held, landings levels, participation in marine-related business outside of SSF, and market prices. An understanding of diversification levels and associated drivers of behavior can help fishery managers and governing entities predict how fishers will react to perturbations. Environmental changes that alter species distributions and increase the potential for invasive species, as well as shifting sociodemographics within the fishing industry, will likely continue to influence diversification behavior in the future. Developing strategies to reduce the impact of these events on fishers and fishing communities will help to increase resilience and reduce vulnerability in SSF.

Mollier, Margaux; Mazé, Camille; Prioul, François; Hamer, Paul; Hosken, Malo; McKechnie, Sam; Tixier, Paul

doi: 10.1093/icesjms/fsae014pmid: N/A

Large marine predators feeding on fish caught on fishing gear, referred to as ‘depredation’, occur in a wide range of fisheries worldwide. Depredation can result in negative ecological and socio-economic impacts, leading to conflict between fishers and depredating species. However, depredation remains understudied in many fisheries, and this hampers the development of effective mitigation solutions. In this study, 21 years of fishing data (2002–2022) were used to assess shark and odontocete depredation in the pelagic tuna longline fishery of New Caledonia. Using generalized linear models, the year, season, effort, soaking time, and vessel were identified as variables significantly influencing the probability of depredation to occur. Results showed that while shark depredation occurred more frequently than odontocete depredation (58.5% vs. 9.2% of the longline sets), they damaged a lower proportion of fish (3.9% vs. 12.3%) over the study period. Unlike sharks, odontocetes selectively depredate tuna, with their highest occurrence during periods of high tuna catch rates, suggesting a co-occurrence with fishing activities. Together, these results indicate that depredation in the New Caledonian fishery is high compared to other regions and provide essential information on the dynamics and impacts of the issue as a basis for considering management and mitigation options.

González-Pola, César; Mills, Katherine E; Beszczynska-Möller, Agnieszka; Bresnan, Eileen; Birchenough, Silvana N R

doi: 10.1093/icesjms/fsae029pmid: N/A

The “Symposium on Decadal Variability of the North Atlantic and its Marine Ecosystems: 2010–2019” took place in Bergen, Norway, from 20 to 22 May 2022. This event, hosted by the Institute of Marine Research, was jointly sponsored by ICES and NAFO and constitutes the fourth in a series of these symposia that started in 1991. The first symposium’s aim was to review the hydrobiological variability in the decade of the 1980s, addressing the physical environment, plankton, invertebrates, and fish. Subsequent symposia maintained the classical structure, whilst a new theme session covering social sciences was added to the programme in the 2022 edition. Studies of climate impacts on marine ecosystems and living marine resources, including trends and regime shifts, emerged from increasingly longer ecosystem time series across the North Atlantic and subarctic regions. This symposium collection presents key findings discussed during the symposium. Whilst some progress has been made in advancing our ability to understand new trends and patterns of climate change and variability across physical, plankton, and fish communities, more work is needed to integrate these physical-ecological processes and scales with social science.

doi: 10.1093/icesjms/fsae046pmid: N/A