Abstract Marine protected areas (MPAs) are globally seen as useful tools to preserve marine biodiversity and restore depleted fisheries. However, high fishing pressure around MPAs could disfavour individuals with large home ranges crossing protected area borders and thereby cause a shift towards less mobile individuals within MPAs. Eventually, this could reduce the benefits of protected areas for both conservation (i.e. phenotypic diversity) and fisheries (i.e. spillover). Here, we tested whether MPAs select against highly mobile phenotypes of European lobster (Homarus gammarus) by using multi-year data (2006–2019) on captures and recaptures of 8020 tagged individuals collected at three MPA-fished area pairs along the Norwegian Skagerrak coast. By applying spatially explicit capture-recapture models to this dataset, we could estimate sigma, a model parameter that reflects the spatial range of the populations, and test for temporal, sex, and size-specific variation in sigma across populations. We found no general evidence that lobsters exhibited higher sigma values in fished areas than in MPAs, nor that spatial range consistently declined through time within protected areas. Although models including temporal variation in sigma performed better than time-constant models, significant declines through time were only statistically supported for male lobsters at one MPA. Furthermore, sex- and size-specific mobility patterns varied markedly among populations. Overall, while selection against mobility may occur in some protected populations, our results suggest that this is not a general consequence of MPA implementation and that the mechanisms regulating lobster spatial behaviour are likely context dependent.
Abstract Explicitly accounting for seasonal variation in resource models allows for more insightful predictions to assist fisheries assessments and management. However, spatio-temporal models that simultaneously estimate seasonal, interannual, and spatial variation in fish data are often overlooked. Here, we encourage the wider use of these models through three illustrative applications. First, we employ fisheries catch rate data for west coast New Zealand snapper (Chrysophrys auratus), to show how a seasonally explicit spatio-temporal model can be utilized to assess stock structure hypotheses. Second, still using the snapper data, we develop a monthly explicit spatio-temporal model to help identify the best months for the West Coast North Island (WCNI) research survey. Finally, we employ Sub-Antarctic research trawl survey data for autumn (March–June) and summer (November–December) to design a seasonally explicit spatio-temporal model for hake (Merluccius australis) that includes a non-linear bottom temperature effect and generate probabilistic forecasts with this model. The hake seasonally explicit model delivered an index of relative biomass that was strongly correlated with the estimated spawning stock and total biomasses from the most recent Sub-Antarctic hake stock assessment. The spatio-temporal model exhibited reasonable predictive skill. We also produced probabilistic forecasts until 2050 with the model, which suggested that the index of relative biomass of Sub-Antarctic hake may increase in the future under the CMIP6 SSP3–7.0 shared socio-economic pathway scenario. Seasonal spatio-temporal models will hopefully be increasingly used to support fisheries assessments and management in the face of climate change, particularly to design optimal designs for research surveys.
Abstract At the inception of the ICES Journal of Marine Science, first published in 1926, elasmobranchs were largely peripheral to fisheries science. Beyond a few commercially valuable species such as basking shark and spurdog, knowledge of occurrence, life history, population structure, and trends of the ∼105 elasmobranch species occurring across the ICES area was limited. This is reflected in the fact that the first elasmobranch-focused paper in the Journal was published by Holden and Meadows in 1964. However, as commercial fisheries expanded and population declines and local extirpations were documented in the late 20th century, elasmobranchs gained increasing attention from both commercial and conservation perspectives. The ICES Working Group for Elasmobranch Fishes, established in 2003, pioneered methods for estimating removals and stock status despite significant data limitations. From issuing the first advice sheets for six “stocks” in 2005, the group now provides assessments for 56 stocks—more than any other ICES assessment group. This review traces the evolution of elasmobranch science within ICES, examining advances in data quality, assessment methodologies, and the shifting priorities that have transformed this taxon from a marginal concern to a central focus of marine conservation and fisheries management. Past and present Working Group Chairs provide perspectives on key developments, persistent challenges, and future directions for elasmobranch research and advice.
Abstract Fishery-independent surveys provide the primary fish relative abundance information for stock assessments, yet their performance can be compromised when the survey area is restricted and population distributions change spatially. Offshore wind development introduces both challenges by precluding some forms of survey sampling within Wind Energy Areas (WEAs) and by potentially altering fish abundance patterns through attraction- or production-driven processes. However, the combined consequences of these mechanisms for survey indices and stock assessment inference remain poorly quantified. The present study evaluated how spatial abundance redistribution interacts with survey preclusion to influence survey-derived indices and assessment outcomes using a simulation-based approach with historical survey datasets. Three Mid-Atlantic stocks (summer flounder, longfin squid, and Atlantic surfclam) were examined to represent contrasting life histories and assessment frameworks. Two redistribution mechanisms were simulated: attraction-driven redistribution, in which abundance increased inside WEAs through spatial reallocation, and production-driven increases, in which local abundance increased without depletion elsewhere. Redistribution was applied at multiple intensities to recent survey data and propagated through assessments using both complete survey coverage (FULL) and spatially truncated datasets excluding WEAs (Wind Energy Excluded; WEE). This simulation-based exercise represented a full-buildout WEA spatial-exposure scenario over a 10-year operational timeframe. Results showed that increasing redistribution intensity elevated overall and interannual variability in survey indices and increased survey residual dispersion from assessment model results, particularly when abundance change inside WEAs was not accounted for. In contrast, monotonic trends inferred from abundance indices remained largely consistent between FULL and WEE datasets. Estimates of spawning stock biomass showed greater sensitivity to spatial redistribution and survey preclusion than fishing mortality, while retrospective patterns exhibited species- and model-specific responses. Together, these findings demonstrate that survey preclusion and altered spatial abundance patterns can interact to influence stock assessment reliability through reducing the precision and accuracy of survey indices. Differences between findings for different stocks highlight the utility of propagating the effect of survey disruptions through assessment models to inform species-specific mitigation strategies, and the need for this type of quantitative analysis to be standard practice as offshore wind development continues to expand.
Abstract The International Council for the Exploration of the Sea (ICES) has included human dimensions in its science and advice selectively and implicitly throughout its history, but formal recognition of social science and humanities as a core research theme only emerged in 2015. This paper examines the circuitous path of how and why ICES evolved towards including human dimensions research. Drawing on key milestones and critical turning points, we identify the drivers that have advanced interdisciplinary and transdisciplinary approaches to fisheries and marine science, as well as the persistent barriers that continue to constrain progress. These barriers include effectively implementing integrated ecosystem-based management science and advice; organizational resistance; awareness, and appropriate use of social sciences; capacity in terms of experts, funding and data; and paradoxes surrounding stakeholder, Indigenous, and rightsholder participation. A self-reinforcing dynamic persists: where human dimensions research is not routinely expected, it is rarely requested; where it is not requested, it is rarely included. Consequently, the ICES advisory system continues to reproduce the very conditions that still keep human dimensions research at the margins. We argue that the challenge is no longer simply to add a human dimension layer to existing science, but to rethink how ICES defines problems and explores solutions, whose knowledge counts, and how experts from different disciplinary and practitioner backgrounds can collaborate to shape just and responsible futures for people and the sea. Fully integrating human dimensions research requires broadening the prevailing scientific paradigm to situate advice within social, cultural, economic, and political realities, and to recognize uncertainty as an inherent feature of coupled social-ecological systems. Such a shift would enable ICES to routinely evaluate management measures across all three pillars of sustainability, providing a more comprehensive evidence base for assessing policy options and their consequences. In doing so, ICES would strengthen its capacity to deliver robust, policy-relevant advice and reinforce its leadership in addressing contemporary fisheries and marine science challenges.
Abstract Traditional single-species fisheries management does not explicitly account for multispecies interactions and has not always performed well for avoiding overfishing or rebuilding many fisheries. Considering these interactions has become increasingly important for effectively managing mixed-species fisheries. Ecosystem-based fisheries management (EBFM) is a more holistic option which considers the biological, physical, and socioeconomic factors influencing stocks and requires new tactics that can be informed by interdisciplinary research. One such approach builds off of portfolio optimization used in the finance field to manage the risk of achieving a target reward through the formation of investment portfolios whereby the constituent assets are selected based on their temporal covariance. A fisheries portfolio involves jointly managing fish stocks that have shared ecological, technical, market, or regulatory interactions. In New England, fishers capture demersal finfish alongside other demersal species resulting in mixed species catches, but these species are currently assessed and managed independently. Here, we examine a candidate portfolio comprising New England demersal finfish with shared technical interactions resulting in mixed species catch, using historical landings and revenue data (1981–2021). Analysis of efficient frontiers indicated that most target revenues could have been achieved with less risk (i.e. of not achieving the target revenue) had a portfolio approach to management been used for these species. Additionally, the sensitivity of this candidate multispecies fishery portfolio to two prominent data decisions was examined, and it was found that risk estimates were sensitive to both the exclusion of species from the initial candidate portfolio and the length of the time series analyzed. Examination of the changes in the frontiers for three periods of the time series characterized by shifts in management regime for this fishery showed that a portfolio approach could improve performance for fisheries utilizing either input or output control systems. These results suggest that portfolio approaches may provide a useful framework for evaluating revenue-risk tradeoffs in multispecies fisheries and represent a potential tool to support EBFM.
Abstract The spatial distribution of marine fish eggs and larvae reflects how biological traits interact with oceanography. Despite developing in a highly dispersive environment, early life stages often display persistent and species-specific spatial patterns, observations that are difficult to explain by behavioural processes alone. This essay explores the idea that buoyancy in this context acts as a key physical process linking eggs and larvae to conservative water-mass properties as salinity and temperature. Species- and population-specific buoyancy characteristics may restrict early life stages to limited three-dimensional habitats, help maintain species-specific spatial associations with hydrographic structures, and bias drift routes towards recurrent nursery areas. The proposed key role of salinity has implications for how climate-driven changes would propagate through early stages and affect recruitment to fish stocks.
Abstract In recent decades, Norwegian waters have experienced several extreme events driven by both environmental and anthropogenic pressures. With ongoing climate change and increased human activities, such events are expected to intensify and differ from those observed in the past. However, scenarios used in ecosystem modelling studies typically emphasize long-term trends and rarely account for extreme events. Here, we address this gap by exploring the ecosystem consequences of archetypal extreme events in Norwegian waters. Using the Norwegian and Barents Sea Atlantis model, we parameterized three extreme scenarios, each with three levels of severity: (1) simultaneous collapse of pelagic fish stocks, (2) increased fishing pressure combined with low cod recruitment, and (3) collapse of marine mammal populations. We quantified the consequences of extreme events at both species or guild and ecosystem levels. Despite very low biomass in key groups, no species went extinct in any scenario. Collapse of small pelagic fish stocks reduced the biomass of predators, such as cod and marine mammals, whereas cod collapse led to increased biomass of small pelagics, marine mammals, and demersal species. Ecosystem impacts were strongest under marine mammal collapse and weakest under cod collapse. Recovery generally occurred within decades, although this may be optimistic given model limitations. No regime shifts were observed, suggesting that models such as Atlantis may have limited ability to capture such dynamics. By simulating diverse scenarios, this approach offers insights into ecosystem responses and vulnerabilities. Future work could test management interventions within the model to assess how mitigation might reduce impacts. Such studies would improve preparedness and resilience in the face of increasingly uncertain and extreme conditions.
Abstract Purse seiners play a crucial role in tuna fishing, as approximately 69% of the world’s tropical tuna is caught using this gear. All tuna Regional Fisheries Management Organizations have established minimum standards for the use of electronic monitoring (EM) in fisheries in addition to traditional observers. These EM systems produce a massive amount of video data that human analysts must process. Integrating artificial intelligence (AI) into their workflow can decrease that workload and improve the accuracy of the reports. However, species identification still poses significant challenges for AI, as achieving balanced performance across all species requires appropriate training data. Here, we quantify the difficulty experts face to distinguish bigeye tuna (BET, Thunnus obesus) from yellowfin tuna (YFT, Thunnus albacares) using images captured by EM systems. We found inter-expert agreements of 42.9% ± 35.6% for BET and 57.1% ± 35.6% for YFT. We then present a multi-stage pipeline to estimate the species composition of the catches using a reliable ground-truth dataset based on identifications made by observers on board. Three segmentation approaches are compared: Mask R-CNN, a combination of DINOv2 with SAM2, and an integration of YOLOv9 with SAM2. We found that the latter performs the best, with a validation mean average precision of 0.66 ± 0.03 and a recall of 0.85 ± 0.03. Segmented individuals are tracked using ByteTrack. For classification, we evaluated a standard multiclass classification model and a hierarchical approach. Their performance depended on the fishing trip considered, suggesting that both approaches are promising, but additional testing is needed to determine which strategy generalizes better overall. All our models were cross-validated during training and tested on fishing operations with fully known catch composition. Combining YOLOv9-SAM2 with the hierarchical classification produced the best estimations, with 84.8% of the individuals being segmented and classified with a mean absolute error of 4.5%.
Abstract Atlantic salmon (Salmo salar) populations are in decline across the species’ range due to multiple pressures in freshwater and marine environments. Farm-to-wild genetic introgression is a significant pressure, leading to loss of genetic adaptation, diversity, and fitness, with potentially negative consequences for life-history traits and survival. A robust understanding of the spatial extent and magnitude of genetic introgression in wild populations is required to inform sustainable management of aquaculture production and wild fish populations. This paper describes a novel approach for quantifying levels of introgression at regional and national scales across Scotland using an informative panel of single nucleotide polymorphism markers, extensive farm and wild baseline samples, and a spatial statistical survey of juvenile salmon populations (National Electrofishing Programme for Scotland, NEPS). Introgression pressures were characterized using two metrics; regional spatial extent of introgression (RSEI) (percentage of river network with hybrids present) and the magnitude of regional introgression (MRI) (mean percentage introgression in a region). RSEI provided a simple metric to link with previous studies in Scotland and elsewhere, whereas MRI allowed the magnitude of introgression to be regionally quantified for the first time. Both metrics were estimated, with standard errors, from the software that accompanies the survey design. Bootstrap hypothesis tests applied to the MRI metric were used to assess the statistical significance of regional introgression pressures. It is estimated that ca. 20% of the river network was affected by introgression at the national scale in 2021, ranging from 0% in some east coast regions to ca. 72% in west coast regions associated with high concentrations of marine aquaculture. At the national scale the mean level of introgression was estimated to be ca. 1%, ranging between 0% on the east to nearly 7% on the west. There were significant levels of introgression in 25 of the 28 regions. This study builds on recent efforts to quantify introgression pressures in support of wild fisheries management and sustainable aquaculture development. It emphasizes the importance of carefully structured juvenile sampling programmes and appropriate statistical approaches for making credible inferences as to the spatial extent and severity of introgression pressures.
Marine carbon dioxide removal (mCDR) is an emerging field where independent, responsibly conducted research is necessary to address uncertainties about effectiveness, safety, feasibility, and desirability. Codes of conduct and calls for community engagement related to mCDR research are growing as public and private entities move forward with field trials. However, these guidelines may not be readily applicable to all projects amidst a rapidly shifting landscape of societal perceptions, media coverage, funding constraints, and local and regional political climates. The Woods Hole Oceanographic Institution's Locking Ocean Carbon in the Northeast Shelf and Slope project, a noncommercial mCDR research program based in the United States, conducted 55 community engagement efforts with local community, industry, and tribal members in 2023-2025, centered around a proposed field trial in the Northeast region. In addition to providing valuable input on project design and implementation, our iterative engagement process honed a framing for the project, explanations of scientific concepts relevant to the study, and answers to common questions raised by community members. We found that open and straightforward dialogue with the strongest opponents to our project led to a set of core messages that spoke to diverse audiences with only slight modifications for different communities. In this narrative account, we reflect on lessons learned through this iterative process, and discuss unresolved questions for community engagement during ongoing and future mCDR field research.
Abstract Fisheries are a main driver of change and loss in marine biodiversity. Maintaining marine ecosystems near targeted states and safely above limit thresholds requires monitoring a suite of ecosystem state indicators that are sensitive to fishing pressures. We synthesized evidence of apparent effects of fishing and whaling on the structure and dynamics of blue-water ecosystems. We assessed the relative strength of evidence of the responses of ecosystem state indicators to fishing and whaling pressures by measuring their prevalence, study approaches, and time series durations. Most indicators with strong evidence were for effects on ecosystem dynamics, including prey and competitive release, reduced trophic transfer efficiency, and rarity of trophic cascades. The latter might be due to thresholds that trigger detectable effects to trophic levels below mesopredators having not been exceeded due to relatively low blue-water fishing pressure and strong compensatory mechanisms. Regime shifts were detected only in marginal seas, which are subject to a broader range of pressures and experience more abrupt shifts relative to unconfined, open ocean systems. Other indicators with strong evidence included: reduced species richness, reduced upper trophic level biomass, and altered size structure of the catch. Several indicators that are potentially informative for blue-water ecosystems were underrepresented, including ecosystem effects of fisheries- and whaling-induced evolution and of habitat alteration. Ecosystem-level consequences of the increased density and altered distributions of floating objects due to the proliferation of fish aggregating devices remain unclear. We identified probable underlying mechanisms for observed responses of blue-water ecosystem state indicators to fishing and whaling pressures. Our findings support fisheries management bodies’ selection of comprehensive suites of informative ecosystem state indicators that span the broad range of ecological responses across blue-water fishery pressures, a core element of robust ecosystem-based harvest strategies.
Marine ecosystems are at risk due to the increasing pressures of climate change and other human activities. Fisheries and aquaculture, which employ 61.8 million people worldwide and supply similar to 20% of human animal protein demand, are sectors that critically rely on healthy marine ecosystems. Marine carbon dioxide removal (mCDR) encompasses a portfolio of novel approaches that aim to mimic natural processes to increase the ocean's uptake and storage of atmospheric carbon dioxide through intentional human interventions in the marine environment. Alongside verifying the efficacy of mCDR techniques, their environmental and social impact must also be assessed to enable informed decisions about what, if any, research, development, and deployment of mCDR should move forward, accounting for the full spectrum of benefits, costs, and trade-offs and in comparison with other CDR interventions. Evaluating the footprint of mCDR requires identifying and understanding positive and negative impacts beyond carbon dioxide removal. Here, we provide a multi-stage research framework for mCDR project developers to assess these interdisciplinary impacts, specifically in relation to marine ecosystems, fisheries, and aquaculture. This framework considers how projects can implement these recommendations across five research phases, using a stage-gated approach that focuses on: Stage 0, Planning; Stage 1, Baseline Assessment and Experiments; Stage 2, Pilot Field Trial; Stage 3, Scaled-up Field Trial; and Stage 4, Operational Deployment and Long-term Monitoring. As an interdisciplinary team of academic and government scientists, non-governmental organizations, and fisheries and Indigenous community members, we offer this framework as a high-level user guide for projects to consider impacts through a fisheries and aquaculture lens. We point to current frameworks when possible and outline additional considerations that can be addressed as research scales.
Field-based research is a common component of marine science and many researchers cite field opportunities as a reason for pursuing a career in the subject. As a result, fieldwork skills are a crucial attribute for marine scientists and opportunities to gain field experience are offered from an early career stage. Positive fieldwork experiences increase productivity, build collaborations, and strengthen a scientist's understanding and appreciation of the natural world. But the isolation and narrow hierarchies that can occur in fieldwork settings sometimes result in hostile working environments, causing significant psychological stress and disrupting career trajectories. In this study, we surveyed fieldwork experiences of marine scientists. We find that positive experiences are related to greater self-confidence, future career ambitions in the field, and further fieldwork opportunities. By contrast, negative experiences are related to poor psychological safety, reduced feelings of value and, in some cases, the decision to leave their career in marine science. Inappropriate behaviour is a common feature of both positive and negative experiences and appears unrelated to the presence of a code of conduct. We suggest that considerably more needs to be done to reduce the amount of inappropriate behaviour in marine science fieldwork settings and provide appropriate support for researchers, especially when early in their careers. Our results indicate that field scientists want fieldwork environments to be safe and stimulating learning environments. By drawing on guidelines developed in other disciplines, we signpost the tools that fieldwork leaders should use to make progress towards realising this aspiration and emphasize the value of positive field environments for both individual and scientific success.
Abstract Human-induced global climate change and other anthropogenic stressors are fundamentally altering our oceans. Understanding the ecological and societal implications of these changes is critical for developing mitigation strategies and conservation measures. However, major components of the marine pelagic ecosystem remain poorly understood. This is true for euphausiids (“krill”), which are a crucial part of marine food webs and play an important role in elemental cycling, including in the biological carbon pump, but for which we know surprisingly little. In this review, we first provide an overview of the ecological and socio-economic value of krill, highlighting their function in marine food webs and biogeochemical cycling. Next, we describe what is currently known regarding the response of krill to climate change and other anthropogenic stressors, focusing on changes in their biogeography, physiology, life history, as well as the impacts of krill fishing and their association with pathogens and parasites. We identify five key gaps in our current knowledge of krill: (1) the effects of krill on food web dynamics and stability, (2) the effects of changing predator and/or prey communities on krill populations, (3) the identification of important krill habitats, (4) the understanding of vertical and horizontal range shifts, and (5) the combined effects of multiple climate change and other anthropogenic stressors on krill. We also highlight the krill species, regions, and habitats that are understudied. Finally, we propose strategies to improve our understanding of this ecologically important taxonomic group, including the sustained funding for time series; implementation of novel research technologies; expanding research on understudied species and regions; and creating a global community of krill researchers.
The Baltic Sea ecosystem is highly impacted by multiple human induced pressures and climate change. Despite this, restoration actions are often directed towards individual measures, ignoring trade-offs and synergies that may affect multiple ecosystem processes and services. Due to the bathymetry of the Baltic Sea, sub-basins may be differently impacted by pressures, making it challenging to observe common patterns and co-occurring processes. Here, we provide the first comprehensive analysis of systemic spatiotemporal changes of food webs across seven Baltic Sea sub-basins. Our analyses cover 26-46 years of harmonized data collection and apply integrated trend analysis in seven sub-basins. We compare temporal trends of key structural food web components, focusing on relative changes between trophic guilds, and interpret these changes in relation to variations in key environmental factors and human pressures. We found shifts in trophic-guild balance and ecosystem reorganization in all sub-basins, which were associated with regional changes in human induced pressures. According to the EU Marine Strategy Framework criteria, this indicates poor food web status across all sub-basins. In some cases, the altered food web regimes have remained despite reductions in the pressures that contributed to the initial shift. Climate warming has played a role, in some cases exacerbating the effects of other human induced pressures. Our results underscore that coordinated actions to reduce pressures such as fishing and nutrient loading are needed to improve food web status in the Baltic Sea.
Abstract Data are essential for assessing the state of seas and oceans as well as for providing feedback on the effects of conservation and management measures. The management of marine data (including its submission, collation, storage, publication, and preservation) has been a key interest of the International Council for the Exploration of the Sea (ICES), since its foundation. This paper tells the story of ICES data management throughout the period 1902–2025—this includes changes and development in some key topics such as data collection platforms and techniques; data groups and data governance within ICES; metadata and data standards; data storage and distribution; and data rescue. The changes in data management are analysed through the lens of the five V’s: volume, variety, velocity, veracity, and value. It shows that the volume and variety have increased significantly, and some aspects of the velocity have increased. Checks of data veracity have become more automated, transparent, and documented over time. ICES data have always been of value to its users but the number of secondary uses of the data have also increased. It also demonstrates that ICES data more clearly reflects the FAIR (Findable, Accessible, Interoperable, and Reusable) principles over time. It discusses how ICES is approaching the ongoing challenges and opportunities of the 21st century in the spirit of international cooperation and collaboration.
Slow-growing, late-maturing deep-sea fish are vulnerable to overfishing and climate change. Tusk (Brosme brosme), an important North Atlantic species, remains understudied across much of its range, limiting fishing advice. We analyzed growth, age, reproduction, and mortality of tusk in the Norwegian and Barents Seas using survey and commercial data from the Norwegian Institute of Marine Research (2000-2022). These analyses provide updated life history parameters essential for stock assessment and management. Using these parameters, we applied the LBSPR model to estimate annual SPR. We also implemented a stochastic version of LBSPR, parameterized with general tusk-like traits, to evaluate how uncertainty in key biological inputs affects SPR estimates when stock-specific parameters are unavailable. This allowed us to evaluate LBSPR as a data-limited, length-based diagnostic, assess how well it aligns with the existing stock assessment framework, and consider its potential applicability to tusk stocks in other regions. Tusk with estimated longevity of 22 years in the Norwegian and Barents Seas appear longer-lived and mature at larger sizes than populations in the Northwest Atlantic. Von Bertalanffy growth parameters varied between sexes, with asymptotic length (L-inf) of 74.4-77.6 cm, growth coefficient (K) 0.11-0.12 year(-)& sup1;, and theoretical age at zero length (t(0)) - 0.42- -0.52 years. Length at 50% maturity (L-5(0)) ranged from 48.3 to 58.1 cm, and age at maturity (A(5)(0)) for males and females was 10.2 and 11.7 years, respectively. Spawning likely occurs from late spring to early summer. Mean stochastic SPR estimates remained high (>41%) in 2001-2022, despite substantial uncertainty. Stock-specific SPR estimates consistently exceeded simulated 95% MSY reference points, and most annual values were above commonly used management targets (SPR > 0.3-0.4). This study fills key knowledge gaps in tusk biology, reveals regional demographic variation, and demonstrates the utility of stock-specific LBSPR for data-limited fisheries. While stochastic LBSPR may be informative when stock-specific data is unavailable, its high uncertainty indicates a need for further refinement. The life history parameters and length-composition summaries developed here are intended as auxiliary inputs to priors on productivity, natural mortality, selectivity, and maturity for upcoming benchmark assessments and future management strategy evaluation work.
Abstract Coastal upwelling sustains some of the most productive marine ecosystems on Earth and exerts a disproportionate influence on the global carbon cycle and climate. Over the past century, the study of upwelling has evolved from early theoretical formulations of wind-driven divergence to a multidisciplinary field spanning physics, biogeochemistry, and ecology. This review, prepared within the framework of the ICES Journal of Marine Science centennial issue, traces a century of progress in understanding Eastern Boundary Upwelling Systems. We revisit the physical foundations established by Ekman and Sverdrup, summarize key advances in the characterization of wind forcing, ocean–atmosphere coupling, and ecosystem response, and highlight emerging perspectives on variability and change under a warming climate. The synthesis reveals how upwelling research has evolved from localized observations to global, integrated approaches that link physical dynamics to biogeochemical feedbacks. Revisiting this history underscores both the enduring relevance of upwelling systems to marine science and the continuing need for coordinated observations and modelling efforts to understand their future trajectory.
Abstract Retrospective patterns are consistent directional changes in terminal year estimates as new data are added and remain one of the most persistent challenges in fishery stock assessment. This paper provides a “retrospective of retrospective analysis,” tracing the evolution of the practice from its early descriptions in the 1980s to its current status as a standard global diagnostic. Using the Georges Bank yellowtail flounder as a case study, I illustrate how strong retrospective patterns can lead to systematic reductions in the perception of biomass and the setting of unsustainable catch quotas, ultimately undermining stakeholder trust in the scientific process. This paper explores the technical shift from virtual population analysis to modern state-space models, such as the Woods Hole Assessment Model, with this technical shift reducing, though not eliminating, retrospective patterns through the use of random effects and environmental covariates. I evaluate current quantification metrics, specifically the widely adopted Mohn’s rho, while discussing the potential advantages of alternative measures. Finally, the paper identifies remaining challenges, including the difficulty of isolating specific causal mechanisms (e.g. missing catch versus changes in natural mortality) and the risks of incorrect model fixes. I conclude by proposing future research directions, emphasizing the role of closed-loop simulations in developing management strategies that are robust to retrospective instability.
