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Considerations for implementing regulation of decapods in science
Get PDFDecapod crustaceans, commonly utilised for pure or applied scientific research and commercial food production, have generally remained outside ethical debate. However, in the last decade many parts of the world have seen an increase in public interest in the welfare of decapod crustaceans and statutory legal protection has been introduced in several countries. Although still limited to a small number of countries and remaining relatively unharmonised, relevant legislation could be increasingly broadened to include decapods in further jurisdictions. Much existing legislation, originally intended for protecting terrestrial vertebrates during scientific study, might be unsuitable for aquatic invertebrates such as decapods. Indeed, precedence with many fish species and cephalopods suggests detail is lacking with respect to fundamental guidance. Therefore, similar inclusion of decapods into such legislation could make welfare or scientific goals more challenging to achieve unless relevant guidance is available, particularly to animal care practitioners. This horizon paper aims to summarise existing decapod legislation, and the considerations required should decapods be included in current conceptual frameworks and scientific legislation.publishedVersio
Buoyancy and vertical distribution of haddock (Melanogrammus aeglefinus) eggs during embryonic development: A comparison with cod (Gadus morhua)
Get PDFVertical egg distributions are needed knowledge for understanding exposure to physical forcing, predation pressure, and modelling initial transport from the spawning areas. Egg density and size are the biotic factors determining vertical distributions while the ambient salinity and turbulent mixing are the physical factors contributing to their vertical distributions. Egg buoyancies and densities of Atlantic cod (Gadus morhua) have been extensively studied, while limited information on haddock (Melanogrammus aeglefinus) egg density is available. This is the first comprehensive study on haddock egg densities in Norwegian waters. Eggs were collected from pairs of spawning fish caught at the coast of western Norway and inserted into a density gradient column where density was measured. The haddock eggs were neutrally buoyant at salinities ranging from 28.5 to 31. The density changed during egg development, and the results from the measurements were used to model the vertical distribution of the eggs. The simulations showed that the changes in buoyancy substantially affected vertical distributions. A comparison to previously published data on cod eggs showed that haddock eggs are considerably more buoyant than the cod eggs and are—particularly during calm wind conditions—confined to the surface layer to a larger extent than the cod eggs. The more buoyant attribute of the haddock eggs, together with the lipophilic surface of the egg membrane, is suggested to make haddock eggs more vulnerable to buoyant pollutants, like hydrocarbons.publishedVersio
Distribution and habitat use of deep-diving cetaceans in the central and north-eastern North Atlantic
Get PDFMajor changes in the distribution of some cetaceans have been observed coincident with changing oceanography of the North Atlantic in the last 30 years. This study aimed to improve understanding of the underlying ecological drivers of any changes in deep-diving cetacean distribution. We used data from two series of summer surveys (in Iceland-Faroes and Norway) to model density of sperm (Physeter macrocephalus), long-finned pilot (Globicephala melas) and northern bottlenose (Hyperoodon ampullatus) whales as a function of static (relief), physical, and biological oceanographic covariates using GAMs. The best models, based on a robust model selection framework, were used to predict distribution. The study period was divided into two periods, 1987‑1989 and 1998-2015, based on environmental changes in the area and data availability. The common covariates that best explained these three species’ distributions (in both periods) were bathymetric variables and SST. The selected dynamic temperature-related covariates for sperm and pilot whales were for spring, but for bottlenose whales were for summer. Summer relationships were also found for the three species for the other dynamic variables, except spring chlorophyll-a for bottlenose whales. The difference in seasonal relationships for bottlenose whales may be related to a previously suggested north-south summer migration. As expected, the predicted high-use areas for all three species were deep waters, with some overlap among them in the central Norwegian Sea, and the Central North Atlantic, including the Irminger Sea. Differences in distribution likely reflect differences in prey. Changes in distribution between the two periods appear more as a range expansion than a shift, which could result from an increase in suitable habitat due to warming waters. This new knowledge will help improve understanding of how these species may respond over this wide area to a changing environment and inform their conservation.Distribution and habitat use of deep-diving cetaceans in the central and north-eastern North AtlanticpublishedVersio
A food-web assessment model for marine mammals, fish, and fisheries in the Norwegian and Barents Seas
Get PDFThe Norwegian and Barents Seas host large commercial fish populations that interact with each other, as well as marine mammal populations that feed on plankton and fish. Quantifying the past dynamics of these interacting species, and of the associated fisheries in the Norwegian and Barents Sea is of high relevance to support ecosystem-based management. The purpose of this work is to develop a food-web model of intermediate complexity and perform a quantitative assessment of the Norwegian and Barents Sea ecosystems in the period 1988–2021 in a manner that is consistent with existing data and expert knowledge, and that is internally coherent. For this purpose, we use the modelling framework of chance and necessity (CaN). The model construction follows an iterative process that allows to confront, discuss, and resolve multiple issues as well as to recognise uncertainties in expert knowledge, data, and input parameters. We show that it is possible to reconstruct the past dynamics of the food-web only if recognising that some data and assumptions are more uncertain than originally thought. According to this assessment, consumption by commercial fish and catch by fisheries jointly increased until the early 2010s, after which consumption by fish declined and catches by fisheries stabilised. On an annual basis, fish have consumed an average of 135.5 million tonnes of resources (including 9.5 million tonnes of fish), marine mammals have consumed an average of 22 million tonnes of which 50 % (11 million tonnes) were fish. Fisheries and hunting have captured an average of 4.4 million tonnes of fish and 7 thousand tonnes of marine mammals.publishedVersio
DIB-X: Formulating Explainability Principles for a Self-Explainable Model Through Information Theoretic Learning
Get PDFThe recent development of self-explainable deep learning approaches has focused on integrating well-defined explainability principles into learning process, with the goal of achieving these principles through optimization. In this work, we propose DIB-X, a self-explainable deep learning approach for image data, which adheres to the principles of minimal, sufficient, and interactive explanations. The minimality and sufficiency principles are rooted from the trade-off relationship within the information bottleneck framework. Distinctly, DIB-X directly quantifies the minimality principle using the recently proposed matrix-based Rényi’s α-order entropy functional, circumventing the need for variational approximation and distributional assumption. The interactivity principle is realized by incorporating existing domain knowledge as prior explanations, fostering explanations that align with established domain understanding. Empirical results on MNIST and two marine environment monitoring datasets with different modalities reveal that our approach primarily provides improved explainability with the added advantage of enhanced classification performance.DIB-X: Formulating Explainability Principles for a Self-Explainable Model Through Information Theoretic LearningpublishedVersio
Transboundary movements of porbeagle sharks support need for continued cooperative research and management approaches
Get PDFDistribution of species across jurisdictional and physical boundaries poses a challenge to management and research, and these transboundary species tend to suffer more-severe population declines from fisheries exploitation. Large pelagic sharks like the porbeagle shark, Lamna nasus, are particularly vulnerable to anthropogenic pressures due to their life history characteristics and their highly migratory behaviour. However, limited knowledge of their precise spatio-temporal movements is particularly challenging for management in situations where jurisdictional boundaries change over small spatial scales. We used satellite tags to demonstrate that porbeagle sharks tagged in the northern Northeast (NE) Atlantic (n = 3), display inter-individual variation in behaviour. Tagged sharks undertook rapid horizontal movements (up to 100 km per day) while transiting through multiple physical habitats and management jurisdictions in a matter of days along different paths. The spatial scale of these movements is important now that the population is deemed in recovery and a new catch advice for porbeagle sharks has been issued by ICES for the first time since 2009 in the NE Atlantic. These movement data highlight the value of existing, and need for continued, regional collaboration to inform sustainable fisheries and conservation management. This is achieved by maximising research impact through cross border funding mechanisms to fill knowledge gaps of species’ life-history and ecology, and, in turn, improve respective outcomes for vulnerable and highly mobile shark species.publishedVersio
Integrating visual and molecular approaches for fish eggs analysis: A study on formaldehyde fixation and storage procedures
Get PDFAccurate taxonomic classification and developmental stage determination of fish eggs are crucial for ecological monitoring, conservation efforts, and stock assessments. Traditional methods for fish and fisheries rely on visual examination of morphological traits, but they face challenges due to species overlap especially for early stages. Molecular tools, such as DNA barcoding, offer higher resolution in taxonomic identification but may not provide developmental stage information. This study explores the effectiveness of different formaldehyde fixation concentrations and storage procedures on fish eggs collected from Lofoten, Norway, for both visual and molecular analysis. Visual analysis successfully identified developmental stage for all fixation solutions. Molecular barcoding using the 16S rRNA gene identified up to 100% of eggs at the species level, with decreasing success rates over time when stored in formaldehyde fixation. The highest DNA barcoding success rates were accomplished using 4% formaldehyde fixation for 12- or 24-h following transfer to ethanol. Using 0.5% and 1% formaldehyde fixation up to 8 weeks also resulted in high DNA success rates, but results deteriorated with increasing storage time. This study provides valuable insights for integrating visual and molecular methods for fish egg analysis, with practical implications for sample preservation during marine surveys.publishedVersio
Maximizing the potential of sustainable aquatic food systems for global food security: key opportunities and challenges.
Get PDFThe development and management of our future aquatic food systems play a pivotal role in achieving the UN sustainable development goals (SDGs). While expanding aquatic food systems align with the ambitions of national 'blue economy' strategies, understanding challenges and opportunities is essential for successful expansion. Three globally relevant case studies—seaweed farming and harvesting, bivalve farming and harvesting, and tuna fisheries—were identified. A literature review revealed challenges and opportunities linked to UN SDGs related to poverty (1), hunger (2), health (3), gender equality (5), responsible consumption (12), climate action (13), and life below water (14). Although no single solution addresses all challenges, the cases emphasize that adapted spatial and ecosystem-based management offers pathways to address major challenges and capitalize on key opportunities.Maximizing the potential of sustainable aquatic food systems for global food security: key opportunities and challenges.publishedVersio
Determination of Nanoparticles and Elements in Blue Mussels (Mytilus edulis) along the Norwegian Coastline
Get PDFOur work aimed to examine nanoparticle levels in 69 distinct pooled mussel samples along the Norwegian coastline, considering samples from different environmental contexts, including natural locations, potentially polluted hotspots, and mussel farms. Single-particle ICP-MS was utilized to determine particle mass and number concentrations at environmentally relevant levels in addition to the total content of 11 elements: aluminum, barium, cerium, copper, iron, manganese, lead, silicon, silver, titanium, and zirconium. Results showed nanoparticle mass concentrations of few ng/g up to tens of μg/g and number concentrations of 106 to 109 particles/g (wet weight). Certain urban and industrially impacted locations were linked to increased levels of, e.g., silver, lead, cerium, zirconium, and titanium NPs. Farmed mussels exhibited lower concentrations. However, natural variations were considerable, and impacted locations mostly did not differ from the highest levels in pristine areas. The study presents the first extensive survey of NPs of 11 different elements in marine biota and provides evidence of increased levels of NPs in areas with anthropogenic activities.publishedVersio
Advancing bioenergetics-based modeling to improve climate change projections of marine ecosystems
Get PDFClimate change has rapidly altered marine ecosystems and is expected to continue to push systems and species beyond historical baselines into novel conditions. Projecting responses of organisms and populations to these novel environmental conditions often requires extrapolations beyond observed conditions, challenging the predictive limits of statistical modeling capabilities. Bioenergetics modeling provides the mechanistic basis for projecting climate change effects on marine living resources in novel conditions, has a long history of development, and has been applied widely to fish and other taxa. We provide our perspective on 4 opportunities that will advance the ability of bioenergetics-based models to depict changes in the productivity and distribution of fishes and other marine organisms, leading to more robust projections of climate impacts. These are (1) improved depiction of bioenergetics processes to derive realistic individual-level response(s) to complex changes in environmental conditions, (2) innovations in scaling individual-level bioenergetics to project responses at the population and food web levels, (3) more realistic coupling between spatial dynamics and bioenergetics to better represent the local- to regional-scale differences in the effects of climate change on the spatial distributions of organisms, and (4) innovations in model validation to ensure that the next generation of bioenergetics-based models can be used with known and sufficient confidence. Our focus on specific opportunities will enable critical advancements in bioenergetics modeling and position the modeling community to make more accurate and robust projections of the effects of climate change on individuals, populations, food webs, and ecosystems.publishedVersio