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The effects of climate change on marine ecosystems are causing cascading impacts on livelihood, food security, and culture through fisheries. Such impacts interact and exacerbate the effects of overfishing on marine social‐ecological systems, complicating the rebuilding of ecosystems to achieve desirable and sustainable ocean futures. Developing effective pathways for ecosystem rebuilding requires consideration of the co‐benefits and trade‐offs between ecological and social dimensions and between fishing sectors. However, the effects of intensifying climate change on such co‐benefits or trade‐offs are yet to be well understood, particularly in regions where ecosystem rebuilding is urgently needed. We applied a numerical optimization routine to define the scope for improvement toward the Pareto‐frontier for ecological robustness and economic benefits of the northern South China Sea (NSCS) and the East China Sea (ECS) ecosystems. These two ecosystems were used to represent over‐exploited low‐ and mid‐latitude systems, respectively, and the optimization aimed to improve their status through fisheries management. We find that the ECS ecosystem has the possibility of increasing the economic benefits generated by the fisheries it supports under climate change by 2050 while increasing the uncertainty of achieving biodiversity objectives. Nevertheless, climate change is projected to reduce the scope to restore ecosystem structures and the potential economic benefits in the NSCS ecosystem. This study highlights the contrasting impacts of climate change on the co‐benefits/trade‐offs in ecosystem rebuilding and the benefits obtainable by different fishing sectors even in neighboring ecosystems. We conclude that consideration at the nexus of climate–biodiversity‐fisheries is a key to developing effective ecosystem rebuilding plan. [ABSTRACT FROM AUTHOR]

Rebuilding overexploited marine populations is an important step to achieve the United Nations' Sustainable Development Goal 14—Life Below Water. Mitigating major human pressures is required to achieve rebuilding goals. Climate change is one such key pressure, impacting fish and invertebrate populations by changing their biomass and biogeography. Here, combining projection from a dynamic bioclimate envelope model with published estimates of status of exploited populations from a catch‐based analysis, we analyze the effects of different global warming and fishing levels on biomass rebuilding for the exploited species in 226 marine ecoregions of the world. Fifty three percent (121) of the marine ecoregions have significant (at 5% level) relationship between biomass and global warming level. Without climate change and under a target fishing mortality rate relative to the level required for maximum sustainable yield of 0.75, we project biomass rebuilding of 1.7–2.7 times (interquartile range) of current (average 2014–2018) levels across marine ecoregions. When global warming level is at 1.5 and 2.6°C, respectively, such biomass rebuilding drops to 1.4–2.0 and 1.1–1.5 times of current levels, with 10% and 25% of the ecoregions showing no biomass rebuilding, respectively. Marine ecoregions where biomass rebuilding is largely impacted by climate change are in West Africa, the Indo‐Pacific, the central and south Pacific, and the Eastern Tropical Pacific. Coastal communities in these ecoregions are highly dependent on fisheries for livelihoods and nutrition security. Lowering the targeted fishing level and keeping global warming below 1.5°C are projected to enable more climate‐sensitive ecoregions to rebuild biomass. However, our findings also underscore the need to resolve trade‐offs between climate‐resilient biomass rebuilding and the high near‐term demand for seafood to support the well‐being of coastal communities across the tropics. [ABSTRACT FROM AUTHOR]

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Arctic sea ice loss has direct consequences for predators. Climate‐driven distribution shifts of native and invasive prey species may exacerbate these consequences. We assessed potential changes by modelling the prey base of a widely distributed Arctic predator (ringed seal; Pusa hispida) in a sentinel area for change (Hudson Bay) under high‐ and low‐greenhouse gas emission scenarios from 1950 to 2100. All changes were relatively negligible under the low‐emission scenario, but under the high‐emission scenario, we projected a 50% decline in the abundance of the well‐distributed, ice‐adapted and energy‐rich Arctic cod (Boreogadus saida) and an increase in the abundance of smaller temperate‐associated fish in southern and coastal areas. Furthermore, our model predicted that all fish species declined in mean body size, but a 29% increase in total prey biomass. Declines in energy‐rich prey and restrictions in their spatial range are likely to have cascading effects on Arctic predators. [ABSTRACT FROM AUTHOR]

Climate change is shifting the distribution of fish stocks that straddle between exclusive economic zones (EEZ), challenging transboundary fisheries management. Here, we examine the projected sharing of jointly managed transboundary fish stocks between Canada and the United States. We hypothesize that ocean warming will alter the sharing of fish stocks between the two countries, and that such changes will intensify under a high carbon emission scenario. We look at the specific cases of the International Pacific Halibut Commission that manages Pacific halibut (Hippoglossus stenolepis) and a resource sharing arrangement in the Gulf of Maine for cod (Gadus morhua), haddock (Melanogrammus aeglefinus), and yellowtail flounder (Limanda ferruginea) to discuss the management consequences of shifts in transboundary stocks. We rely on multiple Earth system models' simulations and species distribution models to estimate the change in catch potential and stock share ratio of each transboundary stock in the 21st century under two climate change scenarios. Results show that, even under a low emission scenario, most transboundary fish stocks sharing ratios, i.e., the proportion of the total catch of a fish stock taken by a given country, will change by 2050 relative to present. The overall reduction in catch potential, in addition to the changes in stock-share will further exacerbate trade-offs between changes in species catch potential. Such trade-offs in the Atlantic and Pacific regions will be amplified if a high emission scenario is followed, relative to a low carbon emission scenario. Based on the simulation results, we examine possible solution options to reduce climate risks on transboundary fish stocks and fisheries. [ABSTRACT FROM AUTHOR]

We apply the concept of threat points in game theory to explore the stability of current joint management arrangements for shared transboundary fish stocks between Canada and the United States. We use three examples to explore the effects of projected impacts of climate change on the productivity and distribution of these stocks between the exclusive economic zones of the two countries. The three stocks that we study are: Atlantic cod (Gadus morhua) and yellowtail flounder (Limanda ferruginea) within the Gulf of Maine, and Pacific halibut (Hippoglossus stenolepis) in the Pacific Coast. We define a threat point as the payoffs that the fisheries in Canada and the United States take home given the current management agreement between the two countries. This is an application of John Nash's threat point, defined as the minimum payoffs that each player in a game theoretic model must receive for the solution to a cooperative game to be stable, which is usually the outcome of a noncooperative game. First, we compute the threat points, that is, the current profits that Canada and the United States derive from the three shared stocks, respectively. Next, we build an ensemble of climate-marine ecosystem and economic models and use them to determine how climate change is likely to change current profits received by each country relative to the shifts in their threat points. We find that in some cases the profits obtained by fisheries in Canada and the United States would change under climate change both in absolute and relative terms resulting in relative changes in threat points. These relative changes in threat points serve as the basis for our discussion of the stability of current transboundary management agreements between Canada and the United States for these important shared stocks in the face of climate change. [ABSTRACT FROM AUTHOR]

Abstract Global warming is already affecting the oceans through changes in water temperature, acidification, oxygen content and sea level rise, amongst many others. These changes are having multiple effects on marine species worldwide, with subsequent impacts on marine fisheries, peoples' livelihoods and food security. This work presents a review of the recent literature on the current and projected impacts of climate change on Canada's Pacific marine ecosystem. We find that there is an increasing number of studies in British Columbia focusing on changes in ocean conditions and marine species responses under climate change, including an emerging literature on the socio-economic impacts of these changes considered to be a knowledge gap. According to the literature, it is well established that ocean temperatures are increasing over the long-term, especially, in southern areas of British Columbia. Warming trends are increasing in the spring and are strongest in summer. However, there are important uncertainties regarding other climate drivers, such as oxygen concentration and acidification, stemming mainly from the insufficiency of data. Pacific salmon, elasmobranchs, invertebrates and rockfishes are amongst the most vulnerable species groups to climate change in British Columbia. Also, shifts in stock distribution and fish abundance under climate change may have a significant impact on fish supply affecting the livelihoods and food security of some British Columbians. The magnitude of these impacts is likely to vary according to a latitudinal gradient, with southern coastal areas being more affected than northern and central areas; challenging multiple areas of governance, such as equity and fishing access amongst First Nations; and institutional arrangements for transboundary stocks between the U.S. and Canada. Highlights • Climate change is impacting marine species worldwide, affecting marine fisheries, peoples' livelihoods and food security. • There is an emerging literature on the socio-economic impacts of climate change at the local level. • This paper presents a review of the literature published on these impacts in British Columbia's marine species and fisheries. • Socio-economic impacts will vary according to a latitudinal gradient with unequal distribution of losses in marine catches. • We identify some of the risks that fisheries, communities and the economy are facing in the region due to climate change. [ABSTRACT FROM AUTHOR]

Fuel forms a significant portion of the total expenditure for many commercial fishing vessels and in some cases, profitability can be dictated by fuel costs. In many nations, including the UK, these fuel costs are reduced by cost-reducing subsidies. There is evidence of growing support from various channels that public opinion is moving towards a reassessment of fuel subsidies. Analysis of the economics of the UK fishing fleet, using publicly available industry-supplied data, implies that the nominal annual value of fuel tax concessions for diesel is between £ 150–180 million per year (2009–2019). That support is largely provided to the most fuel-intensive fishing methods, such as mobile demersal trawls and dredges. Results show that, without the current fuel tax concession, several fleet segments would be deemed unprofitable. This paper outlines the current value of fuel tax concessions for fishing vessels and potential policy considerations for reform. • Foregone government revenue via fisheries fuel subsidies ranged between £ 150–180 m. per year. • UK fleet segments unprofitable without fuel subsidies assuming no changes in fuel use, engine efficiency or activity. • The most fuel intensive fleet segments are more likely to become unprofitable if fuel tax concessions were removed. [ABSTRACT FROM AUTHOR]

Climate change is causing fish stocks to shift, upending the social-ecological systems that rely on the historic distributions of these stocks and creating or exacerbating fisheries conflicts. The movements of internationally shared stocks between Exclusive Economic Zones (EEZs) or between EEZs and the high seas are especially concerning because they bring into play a variety of geopolitical factors and equity issues surrounding missing or conflicting regulations of jurisdictional boundary zones. Though many studies have explored the responses to and repercussions of shifting stocks on fisheries management, there is a dearth of interdisciplinary case studies that provide insight into the complexity of conflict formation in shifting transboundary fisheries, and that highlight the initial response stages where inclusion of proactive and cooperative measures can greatly improve a system's resilience to conflict. Our study helps to fill this gap by drawing on the knowledge of a diverse group of experts to analyze four case studies where transboundary stock shifts, geopolitical or governance tensions, and uncertainty regarding the future of the marine environment collide. Through synthesis of case study findings, we create a causal model of fishery conflict, within which we highlight factors that may heighten or mitigate the risk of conflict over shifting resources such as complex histories of power imbalance, unequal access to resources, or a lack of consistent and transparent data collection. Cooperation and equitable decision-making processes are recognized as vital components of internationally shared stock management which can promote lasting, effective, and conflict-resilient fisheries. [ABSTRACT FROM AUTHOR]

Climate change poses a major challenge for global marine ecosystems and species, leading to a wide range of biological and social-ecological impacts. Fisheries are among the well-known sectors influenced by multiple effects of climate change, with associated impacts highly variable among species and regions. To successfully manage fisheries, scientific evidence about the potential direct and indirect impacts of climate change on the species targeted by fisheries is needed to inform decision-making processes. This is particularly pertinent for fisheries within European seas, as they include some of the fastest warming water bodies globally, and are thus experiencing some of the greatest impacts. Here, we systematically examine the existing scientific climate-related literature of 68 species that are both commercially important in European seas and considered threatened according to the IUCN Red List to understand the extent of information that is available to inform fisheries management and identify critical knowledge gaps that can help to direct future research effort. We also explore the climate and fishing vulnerability indices of species as potential drivers of current scientific attention. We found no literature for most of these species (n = 45), and for many others (n = 19) we found fewer than five papers studying them. Climate change related research was dominated by a few species (i.e., Atlantic salmon, European pilchard, and Atlantic bluefin tuna) and regions, such as the Northeast Atlantic, revealing a highly uneven distribution of research efforts across European seas. Most studies were biologically focused and included how abundance, distribution, and physiology may be affected by warming. Few studies incorporated some level of social-ecological information. Moreover, it appears that research on species with high climate and fishing vulnerabilities is not currently prioritized. These results highlight a gap in our understanding of how climate change can impact already threatened species and the people who depend on them for food and income. Our findings also suggest that future climate-specific adaptation measures will likely suffer from a lack of robust information. More research is needed to include all the species from our list, their relevant geographic regions, and subsequent biological and social-ecological implications. [ABSTRACT FROM AUTHOR]

Letter to the Editor [ABSTRACT FROM AUTHOR]

Climate change is reshaping the way in which contaminants move through the global environment, in large part by changing the chemistry of the oceans and affecting the physiology, health, and feeding ecology of marine biota. Climate change-associated impacts on structure and function of marine food webs, with consequent changes in contaminant transport, fate, and effects, are likely to have significant repercussions to those human populations that rely on fisheries resources for food, recreation, or culture. Published studies on climate change-contaminant interactions with a focus on food web bioaccumulation were systematically reviewed to explore how climate change and ocean acidification may impact contaminant levels in marine food webs. We propose here a conceptual framework to illustrate the impacts of climate change on contaminant accumulation in marine food webs, as well as the downstream consequences for ecosystem goods and services. The potential impacts on social and economic security for coastal communities that depend on fisheries for food are discussed. Climate change-contaminant interactions may alter the bioaccumulation of two priority contaminant classes: the fat-soluble persistent organic pollutants ( POPs), such as polychlorinated biphenyls ( PCBs), as well as the protein-binding methylmercury (MeHg). These interactions include phenomena deemed to be either climate change dominant (i.e., climate change leads to an increase in contaminant exposure) or contaminant dominant (i.e., contamination leads to an increase in climate change susceptibility). We illustrate the pathways of climate change-contaminant interactions using case studies in the Northeastern Pacific Ocean. The important role of ecological and food web modeling to inform decision-making in managing ecological and human health risks of chemical pollutants contamination under climate change is also highlighted. Finally, we identify the need to develop integrated policies that manage the ecological and socioeconomic risk of greenhouse gases and marine pollutants. [ABSTRACT FROM AUTHOR]

Climate change, ocean acidification (OA) and the subsequent changes in marine productivity may affect fisheries and eventually the whole economy in the Arctic. We analysed how changes in climate and ocean pH under scenarios of anthropogenic CO2 emissions are likely to affect the economics of marine fisheries in the Arctic. We applied a Dynamic Bioclimate Envelope Model (DBEM) and outputs from four different Earth System Models (ESMs) to project future changes in the distribution and maximum catch potential of exploited marine fishes and invertebrates. We projected that total fisheries revenue in the Arctic region may increase by 39% (14-59%) by 2050 relative to 2000 under the Special Reports on Emission Scenario (SRES) A2. Simultaneously, total fishing costs, fishers' incomes, household incomes and economy-wide impacts in the Arctic are also projected to increase. Climate change with OA is expected to reduce the potential increases in catch and the economic indicators studied herein. Although the projections suggest that Arctic countries are likely to be 'winners' under climate change in comparison with tropical developing countries, the effects of OA will lower the expected future benefits in the Arctic. The predicted impacts are likely to be conservative as we consider only the direct effects of OA on fishes and calcifiers, of which there are only a few in the Arctic. Results of this study would be useful for designing effective adaptation strategies to climate change and measures to mitigate the potential negative impacts of OA in the Arctic. [ABSTRACT FROM AUTHOR]

The effects of climate change on the ocean environment – especially ocean warming, acidification, and sea level rise – will impact fish stocks and fishers in important ways. Likely impacts include changes in fish stocks' productivity and distribution, human migration to and away from coastal areas, stresses on coastal fisheries infrastructure, and challenges to prevailing maritime boundaries. In this paper, we explore these and other related phenomena, in order to assess whether and how the impacts of climate change on fisheries will contribute to the risk of fisheries conflict. We argue that climate change will entail an increase in the conditions that may precipitate fisheries conflict, and thereby create new challenges for existing fisheries management institutions. Several potential changes in fisheries management policy are recommended to avert the growing risk of fisheries-related conflicts. Climate change is radically reshaping the maritime space – and fisheries in particular – in ways that challenge existing governance institutions and mechanisms, and increase the risk of fisheries conflicts. [ABSTRACT FROM AUTHOR]

The Arctic remains one of the most pristine marine regions in the world, however climate change and increasing favourable conditions is triggering increasing exploration and development of commercial fisheries. Canada's Arctic marine capture fisheries are currently small relative to fisheries in other regions in Canada but small scale, predominantly Inuit fisheries are more wide spread. In this study, catch data was first used to estimate the current state of Arctic marine fisheries. Next, an integrated modelling approach was used to estimate the current and future fisheries potentials under high and low climate change scenarios. Comparisons of the current (2004–2015) annual reported tonnage and modelled estimates (±standard deviation) suggest that annual sustainable fisheries catch potential could be much greater at 4.07 (±2.86) million tonnes than the current catch of 189 (±6.26) thousand tonnes. Under a high climate change scenario, future (2091–2100) fisheries potential was projected to increase to 6.95 (±5.07) million tonnes of catch, while under low climate change scenario catch potential was similar to estimates of current catch potential. However, the greatest source of variance in catch potential estimates came from parameter uncertainty, followed by scenario and model uncertainty. These results contribute to understanding Canada's Arctic marine ecosystems in the face of a rapidly changing environment, yet proper steps must be taken to ensure cultural preservation for Inuit communities as well as ecological, economic, and social sustainability. • Climate change will increase access to Arctic marine fish stocks in Canada. • Projections show positive increases in fisheries catch and value potential with climate change. • Range shifts driven by ocean warming will lead to increased catch potential. • Ocean acidification may reduce projected increase in catch potential. • Ecological, economic, social and cultural impacts of exploitation must be considered. [ABSTRACT FROM AUTHOR]

The article presents the discussion on climate change and fishing presenting dual threats. Topics include important to the homeostasis of the Earth system exhibiting distinctive marine biodiversity and having tremendous scientific impact; and climate regulation and oxygen production through the primary production of seasonal phytoplankton blooms.

In 2017, more than 15,000 scientists from 184 countries signed a second warning letter to humanity to caution against our continued wholesale destruction of global ecosystems (Ripple et al., 2017). Here, we reaffirm their message with a similar warning specifically focused on the ocean: humanity must immediately and significantly alter our harmful trajectory in order to avoid irrevocably damaging our oceans in multiple ways that will further affect ocean health for both us and future generations. The ocean is the world's largest realm, housing an astonishing array of biodiversity that provides critical ecological functions that ultimately support life on Earth. In this paper, we outline some of the significant ongoing and imminent activities that degrade ocean health, including destructive fishing practices, oil and natural gas extraction, seabed mining, coastal development, shipping, pollution, and greenhouse-gas emissions. We end by offering potential avenues to mitigate these impacts, including the cessation of particularly harmful activities, restoration of damaged habitats, strong protection of key and representative ecosystems, reduction in waste and emissions, and global policy shifts that prioritize ecosystem health. • The ocean hosts a vast array of biodiversity that supports all life on Earth. • Ocean health is severely threatened by a large number of anthropogenic stressors. • Humanity must take immediate, transformative action to safeguard our ocean. [ABSTRACT FROM AUTHOR]

• More transboundary fish stocks are expected under climate change, complicating fisheries management. • Linked game theory—ecosystem models test ecosystem-based co-management strategies. • Cooperative, ecosystem-based management of Pacific sardine improves profitability over all fisheries. • Managers must account for the key role of forage fish for ecosystems as well as other fisheries. Transboundary fish stocks complicate sustainable fishing strategies, particularly when stakeholders have diverse objectives and regulatory and governance frameworks. Pacific sardine (Sardinops sagax) in the California Current is shared by up to three fishing nations— Canada, the United States, and Mexico—and climate-driven abundance and distribution dynamics can complicate cooperative fisheries, leading to overfishing. This study builds on previous analyses by integrating ecosystem linkages into a game theory model of transboundary sardine fisheries under various climate scenarios. Cooperative fishing strategies that account for the ecosystem-wide value of sardine as forage for other species result in increased economic benefits compared to strategies that only account for the single-species value of sardine fisheries to a given fishing country. Total ecosystem landed value is maximized at a sardine fishing rate only somewhat lower than sardine F MSY , which is more precautionary but still allows the fishery to operate. Incorporating ecosystem dynamics into management-applicable models can highlight ways in which ecosystem-based fisheries management can improve both sustainability and profitability and help managers prioritize wider ecological research. Ecosystem-based management will be increasingly required to understand and adapt to the observed rapid shifts in species distributions due to climate change, and to design strategies to achieve sustainable and profitable fisheries amidst changing ecosystems. [ABSTRACT FROM AUTHOR]