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Management of natural resources and environmental systems has often involved top-down approaches in which government agencies set and enforce regulations on extractive activities. More recently, market-driven approaches were introduced to incentivise producers to voluntarily engage in practices that align with management objectives and support regulations. For the first time, we compare government and voluntary approaches within fisheries management systems and quantify their relative influences on the sustainability status of fish populations. Voluntary measures include eco-certification against the Marine Stewardship Council's (MSC) Fisheries Standard and Fishery Improvement Projects (FIP). Government-mandated measures are implemented for individual populations, or else at national and international levels. Using a hierarchical time series analysis, we treated each of these measures as independent interventions potentially affecting trends in fishing pressure and biomass of nearly 300 populations. Supporting earlier findings, we confirmed a strong effect of government rebuilding plans in sharply reducing fishing pressure and allowing population biomass to recover. Other government-mandated measures further contributed to reducing fishing pressure. While simultaneously accounting for government measures, we found that biomass increases were associated with stronger incentives generated by voluntary measures. This influence was attributed to the opening of conditions of certification or suspension of certification for MSC fisheries, while no clear influence was attributed to FIPs. MSC certification was rarely observed in the absence of strong government-mandated measures, however, suggesting that sustainability-related incentives associated with voluntary measures can promote more desirable environmental outcomes for target stocks if used in parallel with more conventional approaches to management of natural resources., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ray Hilborn reports financial support was provided by World Wildlife Fund. Ray Hilborn reports financial support was provided by consortium of Seattle fishing companies through the University of Washington. The other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. None of the authors have any interests to disclose, apart from employment with environmental organisations, government agencies or academic institutions involved with researching and advocating for sustainable fisheries management policies., (Copyright © 2025 The Authors. Published by Elsevier Ltd.. All rights reserved.)

While there have been recent improvements in reducing bycatch in many fisheries, bycatch remains a threat for numerous species around the globe. Static spatial and temporal closures are used in many places as a tool to reduce bycatch. However, their effectiveness in achieving this goal is uncertain, particularly for highly mobile species. We evaluated evidence for the effects of temporal, static, and dynamic area closures on the bycatch and target catch of 15 fisheries around the world. Assuming perfect knowledge of where the catch and bycatch occurs and a closure of 30% of the fishing area, we found that dynamic area closures could reduce bycatch by an average of 57% without sacrificing catch of target species, compared to 16% reductions in bycatch achievable by static closures. The degree of bycatch reduction achievable for a certain quantity of target catch was related to the correlation in space and time between target and bycatch species. If the correlation was high, it was harder to find an area to reduce bycatch without sacrificing catch of target species. If the goal of spatial closures is to reduce bycatch, our results suggest that dynamic management provides substantially better outcomes than classic static marine area closures. The use of dynamic ocean management might be difficult to implement and enforce in many regions. Nevertheless, dynamic approaches will be increasingly valuable as climate change drives species and fisheries into new habitats or extended ranges, altering species-fishery interactions and underscoring the need for more responsive and flexible regulatory mechanisms., Competing Interests: Competing interest statement: Some of the authors are involved in fisheries management or provide fisheries advice in ways that can be viewed as competing interests. Many are employed by national fisheries agencies (J.T.W., A.D., M.F., R.F., E.L.H., J.E.J., S.J., J.M., K.R., and K.S.), intergovernmental (J.L. and M. Hall) and nongovernmental organizations (S.A., L.P., L.R., and R. Sharma) or fishing industry (M. Herrera) that advocate for specific fisheries policies. The academic scientists have received funding from sources that include government fisheries agencies (M.P., D.O., S.B., R. Sant'Ana, J.A.S., and R.H.), fishing companies (M.P., D.O., and R.H.), and nongovernmental organizations (M.P., D.O., R. Sant'Ana, and R.H.)., (Copyright © 2022 the Author(s). Published by PNAS.)

Bottom trawling is widespread globally and impacts seabed habitats. However, risks from trawling remain unquantified at large scales in most regions. We address these issues by synthesizing evidence on the impacts of different trawl-gear types, seabed recovery rates, and spatial distributions of trawling intensity in a quantitative indicator of biotic status (relative amount of pretrawling biota) for sedimentary habitats, where most bottom-trawling occurs, in 24 regions worldwide. Regional average status relative to an untrawled state (=1) was high (>0.9) in 15 regions, but <0.7 in three (European) regions and only 0.25 in the Adriatic Sea. Across all regions, 66% of seabed area was not trawled (status = 1), 1.5% was depleted (status = 0), and 93% had status > 0.8. These assessments are first order, based on parameters estimated with uncertainty from meta-analyses; we recommend regional analyses to refine parameters for local specificity. Nevertheless, our results are sufficiently robust to highlight regions needing more effective management to reduce exploitation and improve stock sustainability and seabed environmental status-while also showing seabed status was high (>0.95) in regions where catches of trawled fish stocks meet accepted benchmarks for sustainable exploitation, demonstrating that environmental benefits accrue from effective fisheries management. Furthermore, regional seabed status was related to the proportional area swept by trawling, enabling preliminary predictions of regional status when only the total amount of trawling is known. This research advances seascape-scale understanding of trawl impacts in regions around the world, enables quantitative assessment of sustainability risks, and facilitates implementation of an ecosystem approach to trawl fisheries management globally., Competing Interests: Competing interest statement: The authors have received funds from a range of sources including governments, foundations, nongovernmental organizations, and industries (see Acknowledgements) that have interests in conservation, sustainable use, and effective fisheries management—which may be perceived as a conflict of interest. However, the authors declare that neither these nor any other interests have directly or indirectly influenced the objectivity of this paper, and the findings and conclusions in the paper are those of the authors alone, independent of their organizations or funding sources.

Marine protected areas (MPAs) cover 3-7% of the world's ocean, and international organizations call for 30% coverage by 2030. Although numerous studies show that MPAs produce conservation benefits inside their borders, many MPAs are also justified on the grounds that they confer conservation benefits to the connected populations that span beyond their borders. A network of MPAs covering roughly 20% of the Channel Islands National Marine Sanctuary was established in 2003, with a goal of providing regional conservation and fishery benefits. We used a spatially explicit bioeconomic simulation model and a Bayesian difference-in-difference regression to examine the conditions under which MPAs can provide population-level conservation benefits inside and outside their borders and to assess evidence of those benefits in the Channel Islands. As of 2017, we estimated that biomass densities of targeted fin-fish had a median value 81% higher (90% credible interval: 23-148) inside the Channel Island MPAs than outside. However, we found no clear effect of these MPAs on mean total biomass densities at the population level: estimated median effect was -7% (90% credible interval: -31 to 23) from 2015 to 2017. Our simulation model showed that effect sizes of MPAs of <30% were likely to be difficult to detect (even when they were present); smaller effect sizes (which are likely to be common) were even harder to detect. Clearly, communicating expectations and uncertainties around MPAs is critical to ensuring that MPAs are effective. We provide a novel assessment of the population-level effects of a large MPA network across many different species of targeted fin-fish, and our results offer guidance for communities charged with monitoring and adapting MPAs., (© 2021 The Authors. Conservation Biology published by Wiley Periodicals LLC on behalf of Society for Conservation Biology.)

Forage fish-small, low trophic level, pelagic fish such as herrings, sardines, and anchovies-are important prey species in marine ecosystems and also support large commercial fisheries. In many parts of the world, forage fish fisheries are managed using precautionary principles that target catch limits below the maximum sustainable yield. However, there are increasing calls to further limit forage fish catch to safeguard their fish, seabird, and marine mammal predators. The effectiveness of these extra-precautionary regulations, which assume that increasing prey abundance increases predator productivity, are under debate. In this study, we used prey-linked population models to measure the influence of forage fish abundance on the population growth rates of 45 marine predator populations representing 32 fish, seabird, and mammal species from 5 regions around the world. We used simulated data to confirm the ability of the statistical model to accurately detect prey influences under varying levels of influence strength and process variability. Our results indicate that predator productivity was rarely influenced by the abundance of their forage fish prey. Only 6 predator populations (13% of the total) were positively influenced by increasing prey abundance and the model exhibited high power to detect prey influences when they existed. These results suggest that additional limitation of forage fish harvest to levels well below sustainable yields would rarely result in detectable increases in marine predator populations., (© 2021 Society for Conservation Biology.)

Fishing cooperatives around the world have increasingly taken on co-management of commercial fisheries in recent decades, with generally positive results in meeting management targets and increasing economic value. To better understand which commercial fisheries or fleets are likely to form cooperative associations in the future, we utilized a database of management and fleet-level attributes for 106 fisheries-mainly industrial fisheries from the United States, New Zealand, Canada, and the United Kingdom-to develop a predictive model. We considered two alternative definitions of cooperatives: a legal, operational definition that classified 51 of the fisheries as cooperatives, and a more stringent proactive definition that classified 35 of the fisheries as cooperatives. Random forest classification analyses showed that cooperatives of both types were most likely to form in fisheries with greater boat cost, greater level of participation in industry associations, and in fisheries with bycatch limits; strong regional effects were also observed. Cross-validation prediction accuracy levels were high: using 10 predictor variables, 86% and 91% of fisheries were correctly classified under the operational and proactive cooperative definitions, respectively. These predictions suggest which fisheries may be next to create cooperative fishing associations or engage in more proactive arrangements within cooperatives. These results point to which regulatory reforms, such as flexible bycatch restrictions, could lead to more cooperative behavior in fisheries., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The use of high-throughput, low-density sequencing approaches has dramatically increased in recent years in studies of eco-evolutionary processes in wild populations and domestication in commercial aquaculture. Most of these studies focus on identifying panels of SNP loci for a single downstream application, whereas there have been few studies examining the trade-offs for selecting panels of markers for use in multiple applications. Here, we detail the use of a bioinformatic workflow for the development of a dual-purpose SNP panel for parentage and population assignment, which included identifying putative SNP loci, filtering for the most informative loci for the two tasks, designing effective multiplex PCR primers, optimizing the SNP panel for performance, and performing quality control steps for downstream applications. We applied this workflow to two adjacent Alaskan Sockeye Salmon populations and identified a GTseq panel of 142 SNP loci for parentage and 35 SNP loci for population assignment. Only 50-75 panel loci were necessary for >95% accurate parentage, whereas population assignment success, with all 172 panel loci, ranged from 93.9% to 96.2%. Finally, we discuss the trade-offs and complexities of the decision-making process that drives SNP panel development, optimization, and testing., Competing Interests: The authors declare no conflicts of interest., (© 2020 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)

Ecosystem-based management requires consideration of overlapping resource use between humans and other consumers. Pacific salmon are an important resource for both fisheries and populations of wildlife around the Pacific rim, including coastal brown bears (Ursus arctos); salmon consumption has been positively linked to bear density, body size, and reproductive rate. As a case study within the broader context of human-wildlife competition for food, we used 16-22 yr of empirical data in four different salmon-bearing systems in southwestern Alaska to explore the relationship between sockeye salmon (Oncorhynchus nerka) availability and consumption by bears. We found a negative relationship between the annual biomass of salmon available to bears and the fraction of biomass consumed per fish, and a saturating relationship between salmon availability and the total annual biomass of salmon consumed by bears. Under modeled scenarios, bear consumption of salmon was predicted to increase only with dramatic (on the order of 50-100%) increases in prey availability. Even such large increases in salmon abundance were estimated to produce relatively modest increases in per capita salmon consumption by bears (2.4-4.8 kg·bear -1 ·d -1 , 15-59% of the estimated daily maximum per capita intake), in part because bears did not consume salmon entirely, especially when salmon were most available. Thus, while bears catching salmon in small streams may be limited by salmon harvest in some years, current management of the systems we studied is sufficient for bear populations to reach maximum salmon consumption every 2-4 yr. Consequently, allocating more salmon for brown bear conservation would unlikely result in an ecologically significant response for bears in these systems, though other ecosystem components might benefit. Our results highlight the need for documenting empirical relationships between prey abundance and consumption, particularly in systems with partial consumption, when evaluating the ecological response of managing prey resources for wildlife populations., (© 2019 by the Ecological Society of America.)