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Transform high seas management to build climate resilience in marine seafood supply
Abstract
Climate change is projected to redistribute fisheries resources, resulting in tropical regions suffering decreases in seafood production. While sustainably managing marine ecosystems contributes to building climate resilience, these solutions require transformation of ocean governance. Recent studies and international initiatives suggest that conserving high seas biodiversity and fish stocks will have ecological and economic benefits; however, implications for seafood security under climate change have not been examined. Here, we apply global-scale mechanistic species distribution models to 30 major straddling fish stocks to show that transforming high seas fisheries gover-nance could increase resilience to climate change impacts. By closing the high seas to fishing or cooperatively managing its fisheries, we project that catches in exclusive economic zones (EEZs) would likely increase by around 10% by 2050 relative to 2000 under climate change (representative concentration pathway 4.5 and 8.5), compensating for the expected losses (around À6%) from 'business-as-usual'. Specifically, high seas closure increases the resilience of fish stocks, as indicated by a mean species abundance index, by 30% in EEZs. We suggest that improving high seas fisheries gover-nance would increase the resilience of coastal countries to climate change.
... Among the existing fishery zones, we chose to focus on EEZsarea stretching from the coastline out to 200 nautical miles over which a country has special rights regarding the use of marine resourcesas they are (i) basic units for fisheries management (e.g. attribution of maximum allowed catches by EEZs) and conservation perspectives (Allison et al. 2009, Cheung et al. 2016a, Zeller et al. 2016), (ii) at a spatial resolution welladapted for biogeographic research (Claus et al. 2014) and (iii) commonly used in the literature to project the socio-economics consequences of climate change on fisheries (Sumaila et al. 2011, Cheung et al. 2016a ...
... Among the existing fishery zones, we chose to focus on EEZsarea stretching from the coastline out to 200 nautical miles over which a country has special rights regarding the use of marine resourcesas they are (i) basic units for fisheries management (e.g. attribution of maximum allowed catches by EEZs) and conservation perspectives (Allison et al. 2009, Cheung et al. 2016a, Zeller et al. 2016), (ii) at a spatial resolution welladapted for biogeographic research (Claus et al. 2014) and (iii) commonly used in the literature to project the socio-economics consequences of climate change on fisheries (Sumaila et al. 2011, Cheung et al. 2016a ...
... quantifying changes in the allocation of fisheries catches by maritime country and within EEZ waters allows to focus on a spatial scale that is politically and economically viable (Cheung et al. 2016a, Zeller et al. 2016. Depending on the EEZ, SPFs may experience high fishing mortalities, especially in the Mediterranean Sea (i.e. ...
Environmental conditions are shaping the spatial distribution of marine species worldwide. However, climate change may alter their future distribution, impacting marine resources exploitation and ecosystems balance. In this context, this PhD identifies climate induced impacts in species and geographical areas, by focusing on some species, indigenous or non-indigenous, of commercial interest in the Mediterranean.Based on the ecological niche concept, that defines the potential distribution of a species according to the environmental conditions in which it is observed, we developed a contemporary and future distribution modelling procedure for marine species. This procedure includes an ensemble of statistical algorithms, future climate models and scenarios while accounting for common ecological niche modelling limitations. Applied to small pelagic fish and cephalopods, we projected major climate induced impacts in the Mediterranean Sea by 2100, including local extinctions in its south-eastern basin. Conversely, we projected a distributional range expansion of most of the studied species towards the North, Norwegian and Baltic seas. In the Gulf of Lion, the small pelagic fish distributional range shifts may indirectly impact their harvesting capacity as well as the productivity of low trophic levels. The combined effects of climate warming and the opening of the Suez Canal induced biological invasions, especially in the South-East Mediterranean. These non-indigenous Mediterranean species may be of commercial interest subject to future harvesting. After quantifying the invasive potential of several non-native Mediterranean marine species, according to their functional and ecological traits, we applied our modelling procedure to estimate their future distributional range expansion. We projected a major distributional range expansion of non-native species in the whole Mediterranean Sea by 2100, especially for warming exceeding 2°C.This work highlights the sensitivity of the Mediterranean Sea to climate change while proposing adaptation and conservation perspective of species and ecosystems facing the upcoming climate trends of the 21st century.
... The actions in the first two categories (referred to as global actions hereafter, although some forms of solar radiation management could be local) aim to either reduce the main cause of climate change at the global scale (primarily the increase in atmospheric CO 2 concentration) or to counteract warming through increasing albedo in the atmosphere or at the Earth's surface, thereby increasing the proportion of solar radiation that is reflected back to space. The actions in the other two categories (referred to as local actions hereafter) aim to reduce the risk of climate change impacts locally, either by reducing the locally experienced drivers (site-specific acidification and warming, and relative sea- level rise) and/or reducing the sensitivity of organisms and ecosystems to these drivers ( Bates et al., 2017;Cheung et al., 2017). Vegetation and alkalinization (see Box 1 and section "SM1" of the Supplementary Materials for descriptions) are evaluated for both global and local aims as they can be deployed globally to reduce changes in climate-related drivers and impacts, as well as locally to reduce the sensitivity of marine ecosystems and services to specific drivers such as relative sea-level rise and ocean acidification. ...
... Technical feasibility is evaluated by considering current technological readiness (ranging from schemes at the concept stage to schemes already deployed) and for lead time until full potential effectiveness, i.e., the time needed to reach full implementation (ranging from days to decades; see section Leary et al., 2017), all overexploited and collapsed fish stocks in the process of rebuilding (in 2014, 46% of the total fish stock was overexploited or collapsed) ( Cheung et al., 2017), and pre-disturbance extent of mangroves ( Valiela et al., 2001). (C) Launch date of some major international conventions or protocols providing governance frameworks for the solutions described in panel (A). ...
The Paris Agreement target of limiting global surface warming to 1.5–2°C compared to pre-industrial levels by 2100 will still heavily impact the ocean. While ambitious mitigation and adaptation are both needed, the ocean provides major opportunities for action to reduce climate change globally and its impacts on vital ecosystems and ecosystem services. A comprehensive and systematic assessment of 13 global- and local-scale, ocean-based measures was performed to help steer the development and implementation of technologies and actions toward a sustainable outcome. We show that (1) all measures have tradeoffs and multiple criteria must be used for a comprehensive assessment of their potential, (2) greatest benefit is derived by combining global and local solutions, some of which could be implemented or scaled-up immediately, (3) some measures are too uncertain to be recommended yet, (4) political consistency must be achieved through effective cross-scale governance mechanisms, (5) scientific effort must focus on effectiveness, co-benefits, disbenefits, and costs of poorly tested as well as new and emerging measures.
... At a global scale, current ocean management has, in some cases, led to situations of social injustice in which the loss of biodiversity and its associated benefits has occurred by capitalist forces at the expense of those less empowered, leading to unequal distribution of benefits at the cost of shared resources. For example, 10 countries capture 71% of the landed value of high-seas fish stocks, an area where LSMPAs could help reduce inequality in the distribution of fisheries benefits among the world's nations in a cost-effective fashion (Sumaila et al. 2015, Cheung et al. 2017. Similarly, LSMPAs zoned to allow some extractive use for local people could also be used to promote social justice and food security by enhancing local catches from spillover effects and helping to combat unsustainable fishing by industrial fleets (Standing 2015). ...
... Given that effective protection of important areas, such as spawning or nursery grounds, combined with good fishery management can help rebuild exploited fish stocks, LSMPAs may, in fact, contribute to increasing seafood supply while simultaneously achieving many other benefits, such as habitat protection and climate resilience. (Sumaila et al. 2015, Cheung et al. 2017. ...
Designated large-scale marine protected areas (LSMPAs, 100,000 or more square kilometers) constitute over two-thirds of the approximately 6.6% of the ocean and approximately 14.5% of the exclusive economic zones within marine protected areas. Although LSMPAs have received support among scientists and conservation bodies for wilderness protection, regional ecological connectivity, and improving resilience to climate change, there are also concerns. We identified 10 common criticisms of LSMPAs along three themes: (1) placement, governance, and management; (2) political expediency; and (3) social-ecological value and cost. Through critical evaluation of scientific evidence, we discuss the value, achievements, challenges, and potential of LSMPAs in these arenas. We conclude that although some criticisms are valid and need addressing, none pertain exclusively to LSMPAs, and many involve challenges ubiquitous in management. We argue that LSMPAs are an important component of a diversified management portfolio that tempers potential losses, hedges against uncertainty, and enhances the probability of achieving sustainably managed oceans.
... Protection of coastal wetland nurseries can facilitate the completion of life cycles that require multiple habitats and enhance fisheries (86). These effects can increase food security and prosperity, especially in developing countries (87), and may offset predicted declines in ocean and fisheries productivity (88). ...
... Marine reserves will also help insure against inadequate management both in national waters (137,142) and beyond national jurisdiction (88,143). They extend the precautionary principle to management and ensure that we do not make scientific advances through the belated realization of what we have lost. ...
Strong decreases in greenhouse gas emissions are required to meet the reduction trajectory resolved within the 2015 Paris Agreement. However, even these decreases will not avert serious stress and damage to life on Earth, and additional steps are needed to boost the resilience of ecosystems, safeguard their wildlife, and protect their capacity to supply vital goods and services. We discuss how well-managed marine reserves may help marine ecosystems and people adapt to five prominent impacts of climate change: acidification, sea-level rise, intensification of storms, shifts in species distribution, and decreased productivity and oxygen availability, as well as their cumulative effects. We explore the role of managed ecosystems in mitigating climate change by promoting carbon sequestration and storage and by buffering against uncertainty in management, environmental fluctuations, directional change, and extreme events. We highlight both strengths and limitations and conclude that marine reserves are a viable low-tech, cost-effective adaptation strategy that would yield multiple cobenefits from local to global scales, improving the outlook for the environment and people into the future.
... 30% of fish stocks are caught beyond sustainable limits with 61% considered 'fully fished' (Long, 2018, p. 288). An estimated 62% of the total number of all fish caught in ABNJ was done by only 10 States (Cheung et al., 2017). ...
Part II of The Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction (BBNJ Agreement) is a story of innovation, ambition, and compromise for a framework of information and benefit sharing concerning marine genetic resources of areas beyond national jurisdiction and associated digital sequence information and Traditional Knowledge. Understanding the scope, purpose and proposed implementation of the new treaty requires reflection on the (over) twenty years of preparation leading up to the final treaty text. This introductory chapter for the edited collection ‘Decoding Marine Genetic Resource Governance under the BBNJ Agreement’ analyzes the need for knowledge on marine biodiversity and genetic resources, the jurisdictional context and gaps in ocean governance that the treaty aimed to fill, the preparatory work leading to the negotiations, and the key areas of convergence and divergence during the intergovernmental conference treaty negotiations. It outlines how subsequent chapters in this collection build on this context, by analyzing and interpreting the obligations under the Part II framework and offering practical considerations for its implementation under national law and good scientific practice.
... This becomes increasingly Female fish traders in Nigeria.© Ayodele Oloko vital considering the projected impacts of climate change, which is expected to exacerbate the severity of disruptions in fish supply (Cheung et al. 2017). Aside from its economic benefits, the cooperative model should be leveraged for its ability to disseminate sexual health knowledge and provide a collective approach for women to address broader societal challenges, such as poverty and sexual exploitation in smallscale fishing communities. ...
The natural resources on which small-scale fishing
communities in Sub-Saharan Africa depend are crucial
for both their economic sustainability and as a nutritional
resource in challenging times. Yet, the widespread depletion of fish stocks
across the continent results in numerous adverse socio-economic
and developmental consequences, including abusive labour
conditions, food and nutrition insecurity, harmful fishing
practices, and fish-for-sex exchanges.
... Projections tend to agree that fish stock productivity and abundance will, on average, decline near the equator and increase at higher latitudes [14], with the geographic distributions of the so-called "winners" and "losers" having potentially dire socioeconomic implications for fishing nations [28]. It is important to note that this uniform directionality is not always the case [21], and high levels of localized uncertainty can complicate proactive fisheries management efforts. ...
... Emerging industries, such as seabed mining, offshore renewables, climate interventions, or marine genetic resource harvesting must also be included in the generation of future scenarios [51][52][53]. Accounting for socio-economic trends, such as seafood production and green-technology mineral requirements, or climate change trajectories, is crucially important to craft reliable future scenarios that capture the likely emergence of new patterns of use or risks and how they could be better managed by current or future actors [54][55][56]. ...
... The future ocean might be 'crowded' with diverse drivers competing for resources and space 11 , as new technologies constantly render new remote areas of the ocean accessible to exploitation 11,12 . Many challenges related to the ocean are amplified by the effects of climate change 13 and difficult to address because of the deeply intertwined connections between the ecological, socio-political, and economic spheres 14 , as well as the ecological connectivity between coastal waters and the open ocean 15 . Areas beyond national jurisdiction (ABNJ) are especially vulnerable to industrial activities since no state has the mandate for their protection 16 and high seas resources are instead governed by a complex network of regulations and institutions 11 . ...
The high seas are experiencing a stark increase in industrial activities, with resources being exploited unsustainably and shared unequally. This suggests the need for a transformation, a shift in the deeper structures of the system such as underlying paradigms and mind-sets. We created future visions by combining computational text analysis with a structured, yet creative futuring approach. This process resulted in four science fiction stories, which aim to capture the complexity of the system, embrace the inherent uncertainty of the future and question current unsustainable trajectories, while emphasizing the vastness of future option space. The visions are analyzed using the concept of imaginaries, demonstrating that futuristic stories can be traced back to current realities and the scientific evidence they were based upon. We argue that engaging with alternative futures can open up transformative spaces to rethink the relationships between humans and the high seas, from which novel imaginaries can emerge.
... Storms and cyclones also have devastating consequences for seafood-dependent livelihoods [43]. In communities that rely on seafood for their dietary needs and livelihoods, such as for many small islands, the failure to adapt the whole seafood system can intensively result into cultural issues, identity an economic loss, risking food security [4,16,36], intensively affecting indigenous communities [61]. These already-existing impacts may be exacerbated by extreme events. ...
The current magnitude of ocean extreme events already exceeds the end-of-the-decade scenario estimates, and therefore incremental adaptation measures will render insufficient for seafood-dependent livelihoods. Nevertheless, transformational change is deemed promising, but uncertainties remain as to what activates such processes and how maladaptation outcomes can be avoided. While the science on extreme events is advancing fast, little is known about livelihood adaptation and transformation processes in the context of single or compound ocean extreme events. We identify a set of research priorities: 1) the identification of hotspot areas for coastal compound extreme events, 2) the development of
bottom-up case study analysis of adaptation to extreme events, 3) the identification of constrainers and enablers to livelihood adaptation and transformation under abrupt change, and 4) directing research to contribute to climatechange policy. An effort addressing these key gaps will inform seafood-dependent livelihood adaptation policies for the 2030 Agenda and beyond.
... The highest difference between projected biomass trends comes from the fishing pressure; the biomass is an order of magnitude higher in no-fishing scenarios than in scenarios where fishing is considered. Projected biomasses are also higher with lower fishing pressure in all of the species which may help increase species' resilience to climate change (Cheung et al., 2017;Fernandes et al., 2016;Travers et al., 2010). The higher increase projected under RCP8.5 for both tropical tuna species (yellowfin and skipjack) may be due to their greater affinity with warmer tropical and subtropical regions compared with other tuna species (Muhling et al., 2017) becoming better candidates to expand their distribution and being benefited with the water warming. ...
Tunas and billfishes are the main large pelagic commercial fish species. Tunas comprised around 5.5 million t and USD 40 billion in 2018. Climate change studies and projections estimate that overall, global fisheries productivity will decrease due to climate change. However, there are seldom projections of the climate-driven productivity of the higher trophic levels where tunas and billfishes belong. In this work, we use a mechanistic model to evaluate the effects of climate change and fishing for globally distributed and commercially exploited
seven tuna species and swordfish which are divided into 30 stocks for management purposes, under a range of climate change (RCP 2.6 and 8.5) and fishing scenarios (from no fishing to 1.5 times the fishing mortality (F) at the Maximum Sustainable Yield, FMSY) from two Earth System Models (IPSL and MEDUSA). The results suggest that high trophic level species will be more impacted by climate change than by fishing pressure under the assumption that they remain nearby their MSY levels. However, no-fishing scenarios project much higher biomass. The overall productivity of the target species will decrease by 36% and only the Pacific bluefin showing a slight increase in the future. Five species; Atlantic and Southern bluefins, swordfish, bigeye, and albacore are estimated to decrease in biomass and size at different rates. These species represent almost a third of the landings in the Atlantic Ocean and 10% in the Pacific Ocean being the bluefins, the highest-valued tuna species. On average, the body size is expected to decrease up to 15% by 2050. Fish price and demand are partially driven by body size and therefore, revenues can be reduced even in stocks with an increase in productivity. The fishing industry can adapt to the changing climate by increasing the value of fish through sustainability certifications and reducing fuel consumption and time at sea with higher digitalization. Reducing fuel consumption would also be an additional mitigation measure to climate change since it would reduce CO2 emissions.
... As a result, the ''protection paradox'' observed for corals cannot be generalized to other taxa, and dedicated studies should be performed to test how MPAs affect the climatic resilience of fished species. Although evidence remains scarce, theoretical 65 Effect sizes were calculated as natural log ratios of MPA and controls for resistance, recovery, and expected ecological adaptation of marine organisms. Values represent mean ± 95% CI. ...
Marine protected areas (MPAs) are increasingly being promoted as an ocean-based climate solution. However , such claims remain controversial because of the diffuse and poorly synthesized literature on climate benefits of MPAs. To address this knowledge gap, we conducted a systematic literature review of 22,403 publications spanning 241 MPAs and analyzed these across 16 ecological and social pathways through which MPAs could contribute to climate change mitigation and adaptation. Our meta-analysis demonstrates that marine conservation can significantly enhance carbon sequestration, coastal protection, biodiversity, and the reproductive capacity of marine organisms as well as fishers' catch and income. Most of these benefits are only achieved in fully or highly protected areas and increase with MPA age. Although MPAs alone cannot offset all climate change impacts, they are a useful tool for climate change mitigation and adaptation of social-ecological systems.
... Perhaps the clearest example of this need is in areas beyond national jurisdiction-the "high seas"-that are accessed by all countries, but where no single party is responsible for its use or protection. There is extensive evidence of the linkages between high-seas species and coastal fisheries (Sumaila et al. 2015;Cheung et al. 2017;Vierros et al. 2020), and the lessons of high seas fisheries management are highly relevant for cooperative management within and between nations (Crespo et al. 2019). Aside from shipping routes, fisheries are the most prevalent human activity on the high seas and are often governed by Regional Fisheries Management Organizations (RFMOs). ...
The ability of coastal nations to manage their coastal and marine environments is vital in the development and maintenance of national blue economies following the 2030 Agenda. Thus, capacity development (CD) is an important priority area to strengthen education and training for various stakeholders to help create an appropriately trained workforce able to develop, implement, and expand blue economies, especially in developing countries. The chapter is separated into three parts. Part one provides a synthesis of existing global and regional initiatives that build the foundation of CD for ocean sciences. Some multilateral initiatives that are discussed are the Intergovernmental Oceanographic Commission (IOC) of UNESCO, the Scientific Committee on Oceanic Research (SCOR), and the Partnership for Observation of the Global Ocean (POGO). The Western Indian Ocean Marine Science Association (WIOMSA) is presented as a prime example for a regional CD organization. Part two showcases lessons learned from case studies and success stories from training programs such as summer schools that bring together students from various backgrounds for intensive theoretical and practical training on cross-cutting topics. Part three provides recommendations for scientists, policymakers, and the private industry to accelerate global CD efforts and responses to achieve SDG 14 in the current decade.KeywordsCapacity developmentOcean scienceOcean observations
... Perhaps the clearest example of this need is in areas beyond national jurisdiction-the "high seas"-that are accessed by all countries, but where no single party is responsible for its use or protection. There is extensive evidence of the linkages between high-seas species and coastal fisheries (Sumaila et al. 2015;Cheung et al. 2017;Vierros et al. 2020), and the lessons of high seas fisheries management are highly relevant for cooperative management within and between nations (Crespo et al. 2019). Aside from shipping routes, fisheries are the most prevalent human activity on the high seas and are often governed by Regional Fisheries Management Organizations (RFMOs). ...
The ocean’s contributions to humanity exceeds the products available from it, by absorbing more than 90% of the heat resulting from anthropogenic greenhouse gas emissions. The ocean plays a major role in the global cycles of oxygen, carbon dioxide, nitrous oxide and other gases and rebalances the heat differential between poles and the equator, governing the climate to maintain life on our planet. The need to sustainably observe all areas of the ocean—as well as its unlimited potential for renewable ocean energy—are providing inspiration for new technological innovations. However, it is becoming more evident from recent scientific findings that ocean health is more at risk than previously thought, because different pressures add up and contribute to rapid and unpredictable changes in ocean ecosystems. With renewed, revitalized, and changing global scenarios and the United Nations declaring this decade as the UN Decade of Ocean Sciences for Sustainable Development, countries are moving up the ocean in their national policy agendas. Coastal countries, especially small island developing states, are advocating for socially equitable and environmentally sustainable growth. This will require systematic in-situ ocean data collection to understand today’s ocean and for forecasts, disaster risk reduction and early warning systems for coastal society and infrastructure and for the assessment and management of ocean resources. This chapter discusses in detail the need for and importance of ocean observations linked to the blue economy, using case studies to understand how under-resourced countries are facing the complex challenges of ocean observing.
... The highest difference between projected biomass trends comes from the fishing pressure; the biomass is an order of magnitude higher in no-fishing scenarios than in scenarios where fishing is considered. Projected biomasses are also higher with lower fishing pressure in all of the species which may help increase species' resilience to climate change (Cheung et al., 2017;Fernandes et al., 2016;Travers et al., 2010). The higher increase projected under RCP8.5 for both tropical tuna species (yellowfin and skipjack) may be due to their greater affinity with warmer tropical and subtropical regions compared with other tuna species (Muhling et al., 2017) becoming better candidates to expand their distribution and being benefited with the water warming. ...
... Sustainable seafood supply has been facing multiple challenges from climate change that are projected to continue throughout the 21 st century (Barange et al., 2014;Bryndum-Buchholz et al., 2019;Cheung et al., 2017;Naylor, Hardy, et al., 2021). Human population growth, increases in societal wealth and dietary shifts are expected to continue to drive demand for seafood into the future (Béné et al., 2015;FAO, 2018;Garcia & Rosenberg, 2010;Naylor, Kishore, et al., 2021). ...
The sustainability of global seafood supply to meet increasing demand is facing several challenges, including increasing consumption levels due to a growing human population, fisheries resources over-exploitation and climate change. Whilst growth in seafood production from capture fisheries is limited, global mariculture production is expanding. However, climate change poses risks to the potential seafood production from mariculture. Here, we apply a global mariculture production model that accounts for changing ocean conditions, suitable marine area for farming, fishmeal and fish oil production, farmed species dietary demand, farmed fish price and global seafood demand to project mariculture production under two climate and socio-economic scenarios. We include 85 farmed marine fish and mollusc species, representing about 70% of all mariculture production in 2015. Results show positive global mariculture production changes by the mid and end of the 21st century relative to the 2000s under the SSP1-2.6 scenario with an increase of 17%±5 and 33%±6, respectively. However, under the SSP5-8.5 scenario, an increase of 8%±5 is projected, with production peaking by mid-century and declining by 16%±5 towards the end of the 21st century. More than 25% of mariculture-producing nations are projected to lose 40%–90% of their current mariculture production potential under SSP5-8.5 by mid-century. Projected impacts are mainly due to the direct ocean warming effects on farmed species and suitable marine areas, and the indirect impacts of changing availability of forage fishes supplies to produce aquafeed. Fishmeal replacement with alternative protein can lower climate impacts on a subset of finfish production. However, such adaptation measures do not apply to regions dominated by non-feed-based farming (i.e. molluscs) and regions losing substantial marine areas suitable for mariculture. Our study highlights the importance of strong mitigation efforts and the need for different climate adaptation options tailored to the diversity of mariculture systems, to support climate-resilient mariculture development.
... In the context of climate change, an increase in temperature and in the frequency of extreme climatic events may greatly influence cephalopod recruitment 10 , that is already known for its inter-annual variability 84 . The perspective of sustainable and precautious fisheries management 34,99 has driven the development of recent stock assessment procedure including temperature-induced recruitment variability. Our future projections and centroid evolution provide valuable mid-and long-term information to complement classical stock assessment by identifying geographical areas and species that may experience (i) future variation in environmental suitability (i.e. ...
In a context of increasing anthropogenic pressure, projecting species potential distributional shifts is of major importance for the sustainable exploitation of marine species. Despite their major economical (i.e. important fisheries) and ecological (i.e. central position in food-webs) importance, cephalopods literature rarely addresses an explicit understanding of their current distribution and the potential effect that climate change may induce in the following decades. In this study, we focus on three largely harvested and common cephalopod species in Europe: Octopus vulgaris, Sepia officinalis and Loligo vulgaris. Using a recently improved species ensemble modelling framework coupled with five atmosphere–ocean general circulation models, we modelled their contemporary and potential future distributional range over the twenty-first century. Independently of global warming scenarios, we observed a decreasing in the suitability of environmental conditions in the Mediterranean Sea and the Bay of Biscay. Conversely, we projected a rapidly increasing environmental suitability in the North, Norwegian and Baltic Seas for all species. This study is a first broad scale assessment and identification of the geographical areas, fisheries and ecosystems impacted by climate-induced changes in cephalopods distributional range.
... Representatives from science and the fisheries sector concurred that fisheries policy and management has to adapt to climate change related shifts in the range of relevant species, both native and new species migrating north. Practitioners and scientists mentioned more flexible and faster adapting fisheries policy and management is needed to address the year-to-year changing distributions and abundances of commercially valuable fish stocks (Cheung et al., 2017). The participants argued that catch quota need to include new species to avoid a reducing effect on the total catch by "choke-species" such as cod and hake (Baudron and Fernandes, 2015;Mortensen et al., 2018) and to include new valuable species such as Sea bass and Red mullet (Brander et al., 2003). ...
... We projected the DBEM using three Earth system models ( to match the DBEM 0.5º x 0.5º grid using the nearest neighbor method, and in some cases, bilinear interpolation (Cheung et al. 2017). Finally, we used the model outputs for two scenarios of the Intergovernmental Panel on Climate Change (IPCC)-Representative Concentration Pathways (RCP) 2.6 and 8.5 representing a low greenhouse gas emission (strong mitigation) and a high greenhouse gas emission (week mitigation) scenario, respectively (IPCC 2014). ...
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.
... Climate change is likely the most pressing and crosscutting issue of Anthropocene ocean governance. Governance for climate change requires regulations around a variety of issues such as the ocean's capacity to absorb carbon dioxide from the atmosphere and the resultant changes in pH levels, community responses to deoxygenation, mitigation of impacts of sea level rise and other hazards on SIDS and other coastal nations, and adequate management for shift ing fi sheries ranges (Cheung et al. 2017;Mumby et al. 2017;Pinsky et al. 2018;Wilson and Forsyth 2018). Because of the complexity of climate change impacts, scholarship on this issue tends to be specifi c to particular impacts or ecosystems, such as fi sheries, coral bleaching, or shellfi sh and ocean acidifi cation (Mumby et al. 2017). ...
Recent decades have seen a rapid increase in the diversity of ocean uses and threats, leading to the Anthropocene ocean: a place fraught with challenges for governance such as resource collapse, pollution, and changing sea levels and ocean chemistry. Here we review shifts in ocean governance regimes from the United Nations Convention on the Law of the Sea, the first legal regime for the global ocean, to Sustainable Development Goal 14 and beyond. This second period represents a merging of growing international interest in the ocean as part of the global sustainable development agenda—characterized by a focus on knowledge, collaboration, and the formation of alliances between diverse actors and institutions of environmental governance. To conduct this review, we analyzed literature on changing actors, regimes, and institutional arrangements for ocean governance over time. We conclude with a summary of challenges and opportunities for future ocean governance.
... subsidies), since RFMOs do not have any measures in place which relate to these two targets. Ocean acidification is directly linked to climate change, and to address these impacts, it is important to have robust management in place that is able to respond to these uncertainties (Pentz and Klenk 2017;Cheung et al. 2017;Cheung 2018). Management considerations are addressed by target 14.2 (i.e. ...
In 2015, the international community adopted the United Nations Sustainable Development Goals (SDGs), a goal-setting governance strategy that aims to achieve sustainable development across social, economic, and ecological areas. SDG 14 (‘life below water’) is directed to the sustainable use and conservation of the oceans and marine resources. Regional fisheries management organizations (RFMOs) are key institutions in managing international fisheries and thus have the potential to play a significant role in realizing the attainment of SDG 14. This paper aims to assess how RFMOs could contribute to SDG 14 by examining their treaty texts and implementation of conservation and management measures or collaborative networks. The results of this paper highlights the contribution of RFMOs to targets such as ending overfishing and indicates the need for further attention towards area protection. The findings of the network assessment show that RFMOs mainly cooperate with other RFMOs or fisheries-related organizations, indicating a lack of cooperation with other maritime organizations. Moreover, the objective of most of these collaborations is sharing of information or data, while actions against problems such as the bycatch of non-target species are missing. Thus, this paper highlights how existing regional organizations have the potential to increase their contribution to SDG 14, by aligning more of their work to this goal. To support this process, we developed a list of considerations and actions.
... Those changed conditions are particularly troubling for international management of transboundary fish stocks, i.e. fish stocks that move between and across neighbouring EEZs and high seas. Scholars foresee an increase in the failure of cooperation globally, as the impact of climate change on fish stocks becomes increasingly apparent (Pinsky et al. 2018;Shearman and Smith 2007, 49-55;Cheung et al. 2016). ...
A changing climate will challenge the effectiveness and functioning of existing international resource management structures or international regimes. This is already evident in regimes that manage transboundary fish stocks, where rapid changes in the abundance and distribution of fishery resources threaten international cooperation. This article examines the breakdown in resource cooperation for the northeast Atlantic mackerel fishery where, for over a decade, Coastal States have failed to reach an agreement on the management of the stock after a climate-induced shift in the stock’s distribution. Why did the management regime fail? And what are lessons learnt for such regimes more generally? This article sheds light on the interplay between a relatively weak international regime, domestic interests related to the importance of the national fishing industry and a breakdown in the common principles – fisheries science – that international cooperation is based on. The limited flexibility in the negotiating position of the various states – and thus, the regime at large – can be ascribed to a combination of strong domestic industry influence on negotiating positions, and a disagreement over the appropriate methods to measure stock biomass in tandem with unclear allocation principles. Strengthening existing mechanisms to cooperatively manage shared stocks between Coastal States will be important to avoid such disputes in the future. However, states are weary of relinquishing decision-making powers. Therefore, starting with an agreement on the fundamentals, namely the science that underpins diverging claims, could be a first step towards a long-term solution for the northeast Atlantic mackerel.
... Previous studies demonstrate the importance of local stocks with adaptive diversity to long-term sustainability of fish stocks, fisheries, and ecosystems (Bradbury et al., 2010). Improved projections of how climate change can lead to shifts in the distribution of deep-sea species is critically important in developing effective management measures that account for such changes, especially those spatial measures that aim to preserve refugia areas or local fish stocks, to aid conservation of VMEs, or secure food, income and livelihoods from fisheries (Bates et al., 2019;Cheung et al., 2017Cheung et al., , 2010Gaines et al., 2018;Thresher, Guinotte, Matear, & Hobday, 2015;Tittensor et al., 2010). Such improved projections can also inform the des- climate change, cold-water corals, deep-sea, fisheries, fishes, habitat suitability modelling, octocorals, scleractinians, species distribution models, vulnerable marine ecosystems Howell, & Snyder, 2009). ...
The deep sea plays a critical role in global climate regulation through uptake and storage of heat and carbon dioxide. However, this regulating service causes warming, acidification and deoxygenation of deep waters, leading to decreased food availability at the seafloor. These changes and their projections are likely to affect productivity, biodiversity and distributions of deep‐sea fauna, thereby compromising key ecosystem services. Understanding how climate change can lead to shifts in deep‐sea species distributions is critically important in developing management measures. We used environmental niche modelling along with the best available species occurrence data and environmental parameters to model habitat suitability for key cold‐water coral and commercially important deep‐sea fish species under present‐day (1951–2000) environmental conditions and to project changes under severe, high emissions future (2081–2100) climate projections (RCP8.5 scenario) for the North Atlantic Ocean. Our models projected a decrease of 28%–100% in suitable habitat for cold‐water corals and a shift in suitable habitat for deep‐sea fishes of 2.0°–9.9° towards higher latitudes. The largest reductions in suitable habitat were projected for the scleractinian coral Lophelia pertusa and the octocoral Paragorgia arborea, with declines of at least 79% and 99% respectively. We projected the expansion of suitable habitat by 2100 only for the fishes Helicolenus dactylopterus and Sebastes mentella (20%–30%), mostly through northern latitudinal range expansion. Our results projected limited climate refugia locations in the North Atlantic by 2100 for scleractinian corals (30%–42% of present‐day suitable habitat), even smaller refugia locations for the octocorals Acanella arbuscula and Acanthogorgia armata (6%–14%), and almost no refugia for P. arborea. Our results emphasize the need to understand how anticipated climate change will affect the distribution of deep‐sea species including commercially important fishes and foundation species, and highlight the importance of identifying and preserving climate refugia for a range of area‐based planning and management tools.
... M arine protected areas (MPAs) provide many benefits, such as increasing biomass of commercially important species, protecting biodiversity, sequestering carbon in undisturbed sea bottoms, and mitigating the effects of climate change [1][2][3] . The potential benefits of MPAs for resident species are obvious (for example, safeguarding habitat and reducing fishing mortality), but MPAs may also benefit highly migratory species by protecting important aggregation or spawning areas 4,5 . ...
Two of the largest protected areas on earth are U.S. National Monuments in the Pacific Ocean. Numerous claims have been made about the impacts of these protected areas on the fishing industry, but there has been no ex post empirical evaluation of their effects. We use administrative data documenting individual fishing events to evaluate the economic impact of the expansion of these two monuments on the Hawaii longline fishing fleet. Surprisingly, catch and catch-per-unit-effort are higher since the expansions began. To disentangle the causal effect of the expansions from confounding factors, we use unaffected control fisheries to perform a difference-in-differences analysis. We find that the monument expansions had little, if any, negative impacts on the fishing industry, corroborating ecological models that have predicted minimal impacts from closing large parts of the Pacific Ocean to fishing. There are concerns that expansion of marine protected areas could have negative effects on the fishing industry. Here Lynham et al. demonstrate that the expansion of two of the world’s largest protected areas did not have a negative impact on catch rates in the Hawaii longline fishery.
... Representatives from science and the fisheries sector concurred that fisheries policy and management has to adapt to climate change related shifts in the range of relevant species, both native and new species migrating north. Practitioners and scientists mentioned more flexible and faster adapting fisheries policy and management is needed to address the year-to-year changing distributions and abundances of commercially valuable fish stocks (Cheung et al., 2017). The participants argued that catch quota need to include new species to avoid a reducing effect on the total catch by "choke-species" such as cod and hake (Baudron and Fernandes, 2015;Mortensen et al., 2018) and to include new valuable species such as Sea bass and Red mullet (Brander et al., 2003). ...
Coastal marine environments provide livelihoods as billions of people around the world depend greatly on sustainability efforts in the Blue Economy. In this study, we investigated how stakeholders from important Blue Economy sectors along the German North Sea coast perceive the impacts of climate change on their daily work life and the growth of the Blue Economy. In a two-stage approach we first conducted two stakeholder workshops with representatives from the regional sea food sector, science, NGOs and local authorities, in order to identify important issues linked to climate change affecting environment, society, economy and policy. In the second stage, we conducted semi-structured interviews with key knowledge holders from the Blue Economy, to evaluate and validate the most important issues identified during the first stage, and the impacts on the respective sectors. The workshop participants identified perceptible effects of climate change on their marine environment. Early career scientists showed that they possess a clear focus on measures for climate change adaptation, transdisciplinary approaches and knowledge transfer. The interviews revealed that the climate change effects could be perceived as both negative and positive, depending on the sector. Other issues, especially political decisions and developments are perceived to have a greater immediate impact on the Blue Economy than the slow progress of climate change effects. Additionally, increased human activities, in the form of new or intensified uses like marine renewable energy generation, have a greater influence and lead to conflicts between the Blue Economy sectors. Our study showed that economic and societal stakeholders in Germanys North Sea region are aware of climate change and already perceive its effects on their businesses. Synergies and conflicts between the sectors and political decisions might influence sustainable growth of the Blue Economy in highly contested regions, such as the North Sea basin, much stronger than the effects of climate change. This calls for a more flexible and adaptive approach to policymaking, taking into account the changing environmental, social and economic realities.
... Scenarios of marine protected areas (no-take marine reserves) are implemented by assuming no fishing for all species in spatial cells that are intended to be designed as protected areas ( Figure 2.1) ( Cheung et al., 2017). Idealized scenarios of protected areas of 0%, 10%, 30%, and 50% of the area of high seas were developed (Figure 2.1). ...
Global change drivers, such as population growth, increasing consumption, inequity in resource
distribution, overfishing, climate change and pollution, are challenging the sustainability of global
coupled human-natural seafood production system. Modelling the linkages between the
biophysical and socio-economic components of the seafood production systems is a useful way to
explore the interactions between these drivers and policy responses. Moreover, combining the use
of models and scenarios can then provide quantitative projections for pathways of changes in
ocean human-natural systems.
This report documents a newly developed model, herein called Dynamic Integrated Marine
Climate, Biodiversity, Fisheries, Aquaculture and Seafood Market Model (DIVERSE) to project
future pathways to seafood sustainability under global change. DIVERSE is supported by a system
of linked and harmonised infrastructure of environmental, biodiversity, fisheries and socioeconomic databases (Appendix). In parallel, scenarios of direct and indirect drivers of changes in
the marine human-natural systems are developed based on the Representative Concentration
Pathway (RCP) and the Shared Socioeconomic Pathway (SSP) frameworks.
DIVERSE is grounded in the framework of coupled human-natural systems for the ocean.
Chapter 1 describes the basic structure of DIVERSE and its potential applications. Specifically, the
different sub-components of DIVERSE and their main interconnections are introduced. Some of
the overarching research questions in the context of exploring scenarios and pathways for ocean
futures under climate change that can be addressed by DIVERSE are also highlighted.
... The procedure was stopped at +2.0°C which represents the worst COP 21 scenario expected in the coming years (Hulme, 2016a(Hulme, , 2016b. We decided to apply this type of procedure as it is defined more reliable than using IPCC (AR4 or AR5; Montalto et al., 2016) simulations from current up to the year 2050-2075 based on the Representative Concentration Pathways, RCPs (Moss et al., 2010;Cheung et al., 2017). ...
The on-going climate change threats are rapidly growing at both global and local scales, affecting ecosystems, societies and economies by altering natural distribution and productivity of key commercial species. Although the ecosystem based management (EBM) focuses on ecosystem equilibria, to provide realistic management measures for important activities at sea such as fisheries and aquaculture, there is a need of quantities; mechanistic approaches are suggested as reliable solutions. Here, a Dynamic Energetic Budget (DEB) application studies the link between environmental change (temperature forecasted increasing scenario in a context of COP 21 [Paris climate conference Agreement] and food density increase) and life-history traits of some Mediterranean fishery and aquaculture target species (Engraulis encrasicolus, Dicentrarchus labrax, Mytilus galloprovincialis, Crassostrea gigas). A sensitivity analysis was applied to simulate the effects of future environmental change on the time needed to reach the commercial size and the length at first maturity. We also explored the efficiency of Integrated Multitrophic Aquaculture (IMTA) as a potential management solution in a context of an adaptive EBM. The worst scenario of rising temperatures (+2 °C) seems to reduce the time needed to reach the commercial size in most species and IMTA potentiates the thermal effect on it. A spatial contextualisation of model outcomes allowed disentangling potential conflicts among human activities at sea. The DEB based life history traits approach can provides quantities to inform the management of marine activities at local scale additionally allowing translating complex results into useful figurative representations for stakeholders.
... Fisheries sustainable management has been estimated to have the potential to increase global fisheries production by 10% (Cheung et al., 2017), however, the expected benefits at the local scale are less known and can be in the form of bigger and higher value fish increase (Coll et al., 2013;Bundy et al., 2017). Despite suggestions that adaptation is limited to altering catch size and effort (Easterling et al., 2007) there are in fact many options available, many of which benefit or provide an advantage to small-scale fishers and fish-farmers. ...
Aquatic ecosystems are of global importance for maintaining
high levels of biodiversity and ecosystem services, and for the number of
livelihoods dependent on them. In Bangladesh, coastal and delta
communities rely on these systems for a livelihood, and the
sustainability of the productivity is seriously threatened by both
climate change and unsustainable management. These multiple drivers of
change shape the livelihood dependence and adaptation responses, where a
better understanding is needed to achieve sustainable management in these
systems, while maintaining and improving dependent livelihoods. This need
has been addressed in this study in the region of Satkhira, in the
southwest coast of Bangladesh, where livelihoods are highly dependent on
aquatic systems for food supply and income. Traditional wild fish harvest
in the rivers and aquaculture systems, including ghers, ponds, and crab
points have been changing in terms of the uses and intensity of
management, and suffering from climate change impacts as well. By means
of six focus groups with 50 participants total, and validated by expert
consultations, we conduct an analysis to understand the main perceived
impacts from climate and human activities; and the adaptation responses
from the aquatic system livelihoods. We find that biodiversity has
decreased drastically, while farmed species have increased and shrimp
gher farming turned more intensive becoming the main source of income.
All these changes have important implications for food supply in the
region and environmental sustainability. Dramatic responses taken in the
communities include exit the fisheries and migration, and more adaptive
responses include species diversification, crab fattening and working
more on the pond and gher infrastructure. This study evidences the
results of the combination of multiple stressors in productive systems
and the barriers to adaptation in aquatic ecosystem dependent
communities.
... However, many stocks have been recovering since 2003, largely as a result of better management and significant progress toward fishing at maximum sustainable yield in the EU's northeast Atlantic Ocean and Baltic waters (Cardinale et al., 2013). In tropical marine waters, ocean warming and shifts in net primary production are expected to reduce catch by as much as 30% in the tropics by 2050 relative to recent decades ( Cheung et al., 2016), and fish will also probably get smaller by around 20% dur- ing this period ( Cheung et al., 2013). Freshwater fish have also suffered from extinctions and population declines. ...
... Further, our price database contributes to developing a better understanding of the price fluctuations of ex-vessel prices for estimating value chains for reduction fisheries (e.g., Christensen et al., 2014). Additionally, this Price DB will contribute to the growing literature on socioeconomic scenario development and analyses in fisheries science (e.g., Cheung et al., 2016;Lam et al., 2016). ...
Ex-vessel fish prices are essential for comprehensive fisheries management and socioeconomic analyses for fisheries science. In this paper, we reconstructed a global ex-vessel price database with the following areas of improvement: (1) compiling reported prices explicitly listed as “for reduction to fishmeal and fish oil” to estimate prices separately for catches destined for fishmeal and fish oil production, and other non-direct human consumption purposes; (2) including 95% confidence limit estimates for each price estimation; and (3) increasing the number of input data and the number of price estimates to match the reconstructed Sea Around Us catch database. Our primary focus was to address this first area of improvement as ex-vessel prices for catches destined for non-direct human consumption purposes were substantially overestimated, notably in countries with large reduction fisheries. For example in Peru, 2010 landed values were estimated as 3.8 billion real 2010 USD when using separate prices for reduction fisheries, compared with 5.8 billion using previous methods with only one price for all end-products. This update of the price database has significant global and country-specific impacts on fisheries price and landed value trends over time.
This thesis investigates the influence of spatiotemporal variables on longline catches and the distribution of pelagic fishery resources in the Southwestern South Atlantic Ocean (SWAO), focusing on optimizing sustainable fishing practices. For this, data obtained from the southern Brazilian pelagic longline fleet were analyzed, and statistical modeling methods were applied. In chapter 2, a Bayesian approach was used to demonstrate that adjustments in the setting time of fishing activities and seasonality can reduce incidental catches, such as loggerhead turtles, and increase efficiency in capturing target species like swordfish and tunas. Chapter 3 highlighted that the use of fully nocturnal sets, instead of partially nocturnal sets, not only reduces impacts on vulnerable species but also increases profitability. Chapters 4 and 5 conducted comprehensive bibliometric analysis of the use of species distribution models (SDMs) and ecological niche models (ENMs), highlighting global trends and specific applications in the SWAO. This analysis covered aspects such as the number of scientific publications over the years, the main taxonomic groups studied, collaboration networks between countries and authors, and the methods most frequently employed. These results provide a detailed overview of the state of the art and gaps in the use of SDMs and ENMs for fishery resources and organisms inhabiting the SWAO. Finally, in chapter 6, the application of SDMs revealed seasonal patterns in the distribution of escolar (Lepidocybium flavobrunneum), strongly correlated with environmental and oceanographic predictors such as the Current of Brazil, upwelling zones and lunar illumination index. In conclusion, the thesis emphasizes the importance of integrating spatiotemporal approaches and predictive modeling for adaptive management and conservation of fishery resources. Despite the advances presented, further studies are needed to further optimize sustainable management strategies.
To ensure sustainable seafood production for future generations, seafood businesses must be resilient in the face of future shocks and stresses. Recent research suggests that by increasing alignment with principles of circular economy such as eliminating waste and regenerating natural environments, seafood companies may be able to improve their general resilience (i.e. resilience to unforeseen disruptions). Research presented here empirically explores potential links between circular economy, risk mitigation and resilience through a survey and workshops with seafood businesses in the United Kingdom. We found that many of the seafood companies participating in our research are actively implementing a range of circular economy actions such as recycling materials and minimising the use of single-use plastics. When identifying specific risks, businesses tended to adopt short-term mitigation measures that were less likely than longer-term measures to be aligned with circular economy principles. While businesses felt confident about their ability to adapt to and survive future risks, a focus on short-term risk mitigation might reduce their capacity to plan for longer term risks. An inability to identify and prepare for longer-term risks may also impede businesses’ ability to increase their resilience to unforeseen disruptions and lock companies into a reactive, rather than a capacity-building cycle of risk mitigation.
The essential role of coastal fisheries in the Blue Economy is discussed, highlighting the importance of science and technology in their economic and social contexts, as well as that of good governance for their sustainability. The evolution and present situation of global fishery activities are discussed, as well as the effects of fishing on the environment. The worldwide problem of “seafood fraud” by mislabelling is also presented, together with recent technologies and methods to counteract it. Fisheries development trends observed in an industrialized country are presented to illustrate the long steps leading to a new fishing regime after the depletion of fishery stocks. Biological, economic, social and political considerations are discussed together with the importance of stakeholder participation in local and international fishery settings. The main effects of climate change on fisheries are discussed, emphasizing the vital need for adaptation strategies to reduce their impacts. The application of the targets of the Sustainable Development Goal 14 (Life Below Water) is illustrated from a global perspective, stressing the contribution of science and technology. Finally, the importance of fisheries for the Blue Economy is discussed, focusing on the need for equity, an essential factor for support and success.KeywordsCoastal fisheriesSustainable fisheriesSeafood fraudFisheries subsidiesFisheries governanceSDG 14
Transformative governance is key to addressing the global environmental crisis. We explore how transformative governance of complex
biodiversity–climate–society interactions can be achieved, drawing on the first joint report between the Intergovernmental Panel on Climate
Change and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services to reflect on the current opportunities,
barriers, and challenges for transformative governance. We identify principles for transformative governance under a biodiversity–climate–
society nexus frame using four case studies: forest ecosystems, marine ecosystems, urban environments, and the Arctic. The principles are
focused on creating conditions to build multifunctional interventions, integration, and innovation across scales; coalitions of support; equitable
approaches; and positive social tipping dynamics. We posit that building on such transformative governance principles is not only possible but
essential to effectively keep climate change within the desired 1.5 degrees Celsius global mean temperature increase, halt the ongoing accelerated
decline of global biodiversity, and promote human well-being.
As an important part of the national economy, the marine economy will be subject to various internal and external disturbances in the process of development. Different regions will show different resilience. Based on four dimensions of “resistance–recovery–reorientation–renewal,” this paper measures the marine economic resilience of the four provinces covered within the China’s Southern Marine Economy Circle from 2008 to 2018 by establishing an evaluation index system. The results show that 1) the overall resilience of economy in the Southern Marine Economy Circle showed a fluctuating upward trend from 2008 to 2018. Although there was a decline in 2011–2012 due to natural disasters, the value quickly resumed its increasing trend. 2) At present, there are obvious relative differences in the resilience of marine economy in each region of China’s Southern Marine Economy Circle, and the polarization phenomenon is serious. Among them, Guangdong belongs to the high-value region and Fujian is in the middle, while Hainan and Guangxi are temporarily in the low-value area.
The global decline of marine fish stocks calls for sustainable fisheries management based on reliable quantitative estimates. Dynamic spatial distributions of fish populations respond to biological, environmental and anthropogenic drivers. Species distribution models involving data from those areas enable projection of fish presence and abundance. They rely on an international fisheries independent survey effort across large spatial scales by multiple agencies with different equipment. Typically, surveys focus on individual geographical or jurisdictional regions, which are not reflective of natural species ranges. This generates the challenge, how to best combine heterogeneous fisheries survey data for marine species distribution research. Therefore, a standardisation protocol which generated a Quality Assurance–Quality Audited dataset of groundfish surveys was developed. Its public availability constitutes an important contribution to the European fisheries research community and has led to applications in inferential studies outside the scope of this dissertation. A modelling framework for combining fisheries surveys to examine species distribution on a multi-regional scale for the North East Atlantic Ocean was devised. It allowed evaluation of relative efficiency of gear-vessel combinations on 19 surveys for 254 species-length combinations. Estimated relative differences in catch efficiencies grouped strongly by gear type, but there were no clear patterns across the species’ functional forms.
A critical evaluation of species distribution modelling approaches evaluated the potential
for, and limitations of, tracking current and future spatial distribution of marine taxa and
characterizing habitat niches. The application of generalised additive models to presence�absence data provided the most consistent resultsfor four test species (Raja microocellata, Leucoraja naevus, Eutrigla gurnardus and Sebastes viviparous), which were categorised as “local”/“widespread” and “common”/“rare” to capture distribution patterns within the survey data. Among tested environmental variables mean seafloor temperature was most influential and thus appears fundamental to understanding the drivers of change in species distributions, particularly in changing climates.
Evaluation of the economic impacts of marine protected areas is hampered by the fact that it is impossible to observe what would have happened if the protected area had never been closed to fishing (the counterfactual). Catch reports and vessel tracks are used to perform an analysis of the potential negative economic impacts of establishing the Northeast Canyons and Seamounts Marine National Monument (located off the east coast of the United States of America) on three commercially important fisheries that were identified as having potential to be harmed. I conclude that there was little to no negative impact on any of the fisheries. I also test for, but find no evidence of, a Blue Paradox effect. Due to political factors largely unrelated to fisheries status, the protected area was reopened to commercial fishing on June 5th, 2020. I use this event, which was reversed sixteen months later, to test whether there were any economic benefits from reopening. I do not observe an increase in catch, a reduction in distance traveled, or an increase in relative fishing effort inside the protected area (compared to historical trends), consistent with the post-closure findings.
The concept of resilience gained increased attention in sustainability science, with a notable spike from 2014 onwards. However, resilience is a multifaceted concept with no unanimous definition, making applications in the context of sustainability, a similarly multifarious term, a challenge. Here, we examine the use of resilience in well-cited sustainability literature in the period from 2014 to 2018. Based on our analysis, resilience as a concept proves its analytical strength through a diverse set of frameworks, indicators, and models, while its usefulness as boundary object is less clear. Most of the examined publications do not cite one of the well-established resilience definitions as a conceptual basis. The normativity of resilience is often implicit and rarely critically questioned, and strong participatory approaches are lacking. A multivariate statistical full-text bibliographic analysis of 112 publications reveals four distinct research clusters with partial conceptual proximity but hardly any overlap. While the majority of publications consider human well-being as an integral factor in their research, some research marginalizes this concept. Resilience to climate change dominates the discourse in the literature investigated, which signifies a need to broaden research efforts to other equally pressing—but in terms of the concept, widely neglected—sustainability challenges.
The spectre of increasing impacts on exploited fish stocks in consequence of warmer climate conditions has become a major concern over the last decades. It is now imperative to improve the way we project the effects of future climate warming on fisheries. While estimating future climate‐induced changes in fish distribution is an important contribution to sustainable resource management, the impacts on European small pelagic fish—representing over 50% of the landings in the Mediterranean and Black Sea between 2000 and 2013—are yet largely understudied. Here, we investigated potential changes in the spatial distribution of seven of the most harvested small pelagic fish species in Europe under several climate change scenarios over the 21st century. For each species, we considered eight Species Distribution Models (SDMs), five General Circulation Models (GCMs) and three emission scenarios (the IPCC Representative Concentration Pathways; RCPs). Under all scenarios, our results revealed that the environmental suitability for most of the seven species may strongly decrease in the Mediterranean and western North Sea while increasing in the Black and Baltic Seas. This potential northward range expansion of species is supported by a strong convergence among projections and a low variability between RCPs. Under the most pessimistic scenario (RCP8.5), climate‐related local extinctions were expected in the south‐eastern Mediterranean basin. Our results highlight that a multi‐SDM, multi‐GCM, multi‐RCP approach is needed to produce more robust ecological scenarios of changes in exploited fish stocks in order to better anticipate the economic and social consequences of global climate change.
Marine fish stocks and the ecosystems they inhabit are in decline in many parts of our ocean, including in some European waters, because of overfishing and the ecosystem effect of fishing in general. Simultaneously, climate change is disrupting the physics, chemistry and ecology of the ocean, with significant consequences on the life it holds. While the positive effects of mitigating climate change on the ocean and marine life are currently being documented, papers that examine how ending overfishing could increase ocean resilience to climate change are less common. The goal of this paper is to review the current literature and conduct an analysis that demonstrate that ending overfishing and reducing other negative ecosystem effects of fishing would make fish stocks and marine ecosystems more resilient to climate change. Our findings suggest that fish and fish stocks are no different from other living organisms and are more likely to survive external pressures when healthy.
The western and central Pacific Ocean (WCPO) tuna fishery is one of the world's largest in terms of both catch volume and value, providing over half of global tuna catch with a landed value of US 1.4 billion when industry benefits were maximized to $0.2 billion when subsidization was minimized. Investigation of suboptimal scenarios reveals the flexibility of these results, with wide ranges in outputted state variables for a given goal. Difficulty was encountered in modelling the SSF sector due to data deficiencies, a well‐recognized issue in managing SSF. Investments towards “data equity” to help ensure that management decision‐making can properly account for the SSF sector would be useful. This study has implications for the objectives we set in fisheries management, and the potential trade‐offs, often value‐driven in nature, that we must make explicit in that management.
The management of international fisheries is a fundamental pillar of the Common Fisheries Policy (CFP). The relationship between internal and external fisheries policy in the CFP is two‐sided: the external policy conditions much of the fisheries policy in the European Union (EU), and the EU itself plays an important role in defining international fisheries policy. This chapter examines the main challenges of international fisheries and the role that the EU can play. It also analyses how to face future challenges and how to position the CFP in the increasingly complex multilateral management of fisheries in the years to come.
Assessment of past fisheries productivity helps to predict and manage future changes
Key messages
• Pakistan, India, Bangladesh, Myanmar and Maldives are among the countries
most affected by climate change and weather events.
• There is strong socio-economic pressure from population growth, presence of
dams and irrigation needs, heavy metal and waste pollution, habitat modification
and destruction, illegal fishing, and insufficient infrastructure, skills credit and
welfare.
• Inland fisheries captures are high and interlinked with the marine environment
in countries where fisheries are important for employment, exports and income
generation.
• Artisanal and subsistence fisheries are important in the region; however, the
number of artisanal boats is decreasing probably as a result of over-exploitation
and overcapacity.
• Marine maximum potential productivity is likely to decrease in those regions
because of climate change, but that potential is not being achieved at present
because of overfishing. This suggests that climate change impacts on specific
fisheries can be partly mitigated by improving fisheries management.
• In many countries, government institutions have long-term plans that recognize
the likely impacts of climate change. With limited resources, they are trying to
establish and enforce fisheries management measures which can increase the
resilience of communities to climate change.
• A lack of resources and scientific knowledge is often addressed through
internationally funded cooperative research and support programmes that
encourage ecosystem- and community-based approaches and science-driven
management advice.
• International fisheries safety and sustainability certifications are a successful
driver of change and have the potential to improve infrastructure, people training,
commodity values, diversify markets and support the ecological sustainability of
the activities of associated industries.
• Increased economic stability of fishers and associated industries through easy
and low-cost access to insurance, welfare, credits and minimum wages is being
promoted through government and non-government agencies; however, they can
only reach a very small number of the people whose livelihoods are impacted by
climate change.
This paper aims to highlight the risk of climate change on coupled marine human and natural systems and explore possible solutions to reduce such risk. Specifically, it explores some of the key responses of marine fish stocks and fisheries to climate change and their implications for human society. It highlights the importance of mitigating carbon emission and achieving the Paris Agreement in reducing climate risk on marine fish stocks and fisheries. Finally, it discusses potential opportunities for helping fisheries to reduce climate threats, through local adaptation. A research direction in fish biology and ecology is proposed that would help support the development of these potential solutions.
Monitoring of fisheries fleets provides crucial data for sustainable use of ocean resources
Reversing biodiversity loss by 2020 is the objective of the 193 countries that are party to the global Convention on Biological Diversity (CBD). In this context, the Aichi Biodiversity Targets 2020 were agreed upon by the CBD in Nagoya, Japan in 2010 and this was followed by asking a high-level panel to make an assessment of the financial resources needed to achieve these targets globally. First, we review the literature on the costs and benefits of meeting the Aichi Targets. Second, we provide a summary of the main conclusions of the CBD High-Level Panel (HLP) 1 and 2 on the Global Assessment of the Resources for Implementing the Strategic Plan for Biodiversity 2011–2020. A key conclusion of the HLP is that the monetary and non-monetary benefits of biodiversity conservation and sustainable use to be achieved by implementing the Aichi Targets would significantly outweigh the amount of investments required.
Significance
What would extensive fishery reform look like? In addition, what would be the benefits and trade-offs of implementing alternative approaches to fisheries management on a worldwide scale? To find out, we assembled the largest-of-its-kind database and coupled it to state-of-the-art bioeconomic models for more than 4,500 fisheries around the world. We find that, in nearly every country of the world, fishery recovery would simultaneously drive increases in food provision, fishery profits, and fish biomass in the sea. Our results suggest that a suite of approaches providing individual or communal access rights to fishery resources can align incentives across profit, food, and conservation so that few trade-offs will have to be made across these objectives in selecting effective policy interventions.
model ensemble projections of climate change effects on global marine biodiversity. – ICES Species distribution models (SDMs) are important tools to explore the effects of future global changes in biodiversity. Previous studies show that variability is introduced into projected distributions through alternative datasets and modelling procedures. However, a multi-model approach to assess biogeographic shifts at the global scale is still rarely applied, particularly in the marine environment. Here, we apply three commonly used SDMs (AquaMaps, Maxent, and the Dynamic Bioclimate Envelope Model) to assess the global patterns of change in species richness, invasion, and extinction intensity in the world oceans. We make species-specific projections of distribution shift using each SDM, subsequently aggregating them to calculate indices of change across a set of 802 species of exploited marine fish and invertebrates. Results indicate an average poleward latitudinal shift across species and SDMs at a rate of 15.5 and 25.6 km decade 21 for a low and high emissions climate change scenario, respectively. Predicted distribution shifts resulted in hotspots of local invasion intensity in high latitude regions, while local extinctions were concentrated near the equator. Specifically, between 108N and 108S, we predicted that, on average, 6.5 species would become locally extinct per 0.58 latitude under the climate change emissions scenario Representative Concentration Pathway 8.5. Average invasions were predicted to be 2.0 species per 0.58 latitude in the Arctic Ocean and 1.5 species per 0.58 latitude in the Southern Ocean. These averaged global hotspots of invasion and local extinction intensity are robust to the different SDM used and coincide with high levels of agreement.
The ocean moderates anthropogenic climate change at the cost of profound alterations of its physics, chemistry, ecology, and services. Here, we evaluate and compare the risks of impacts on marine and coastal ecosystems-and the goods and services they provide-for growing cumulative carbon emissions under two contrasting emissions scenarios. The current emissions trajectory would rapidly and significantly alter many ecosystems and the associated services on which humans heavily depend. A reduced emissions scenario-consistent with the Copenhagen Accord's goal of a global temperature increase of less than 2°C-is much more favorable to the ocean but still substantially alters important marine ecosystems and associated goods and services. The management options to address ocean impacts narrow as the ocean warms and acidifies. Consequently, any new climate regime that fails to minimize ocean impacts would be incomplete and inadequate.
Copyright © 2015, American Association for the Advancement of Science.
Cheung, W. W. L., Dunne, J., Sarmiento, J. L., and Pauly, D. 2011. Integrating ecophysiology and plankton dynamics into projected
maximum fisheries catch potential under climate change in the Northeast Atlantic. – ICES Journal of Marine Science, 68: 1008–1018.
Previous global analyses projected shifts in species distributions and maximum fisheries catch potential across ocean basins
by 2050 under the Special Report on Emission Scenarios (SRES) A1B. However, these studies did not account for the effects
of changes in ocean biogeochemistry and phytoplankton community structure that affect fish and invertebrate distribution and
productivity. This paper uses a dynamic bioclimatic envelope model that incorporates these factors to project distribution
and maximum catch potential of 120 species of exploited demersal fish and invertebrates in the Northeast Atlantic. Using projections
from the US National Oceanic and Atmospheric Administration's (NOAA) Geophysical Fluid Dynamics Laboratory Earth System Model
(ESM2.1) under the SRES A1B, we project an average rate of distribution-centroid shift of 52 km decade−1 northwards and 5.1 m decade−1 deeper from 2005 to 2050. Ocean acidification and reduction in oxygen content reduce growth performance, increase the rate
of range shift, and lower the estimated catch potentials (10-year average of 2050 relative to 2005) by 20–30% relative to
simulations without considering these factors. Consideration of phytoplankton community structure may further reduce projected
catch potentials by ∼10%. These results highlight the sensitivity of marine ecosystems to biogeochemical changes and the need
to incorporate likely hypotheses of their biological and ecological effects in assessing climate change impacts.
Fishing takes place in the high seas and Exclusive Economic Zones (EEZs) of maritime countries. Closing the former to fishing has recently been proposed in the literature and is currently an issue of debate in various international fora. We determine the degree of overlap between fish caught in these two areas of the ocean, examine how global catch might change if catches of straddling species or taxon groups increase within EEZs as a result of protection of adjacent high seas; and identify countries that are likely to gain or lose in total catch quantity and value following high-seas closure. We find that ,0.01% of the quantity and value of commercial fish taxa are obtained from catch taken exclusively in the high seas, and if the catch of straddling taxa increases by 18% on average following closure because of spillover, there would be no loss in global catch. The Gini coefficient, which measures income inequality, would decrease from 0.66 to 0.33. Thus, closing the high seas could be catch-neutral while inequality in the distribution of fisheries benefits among the world's maritime countries could be reduced by 50%.
Growing human populations and changing dietary preferences are increasing global demands for fish, adding pressure to concerns over fisheries sustainability. Here we develop and link models of physical, biological and human responses to climate change in 67 marine national exclusive economic zones, which yield approximately 60% of global fish catches, to project climate change yield impacts in countries with different dependencies on marine fisheries. Predicted changes in fish production indicate increased productivity at high latitudes and decreased productivity at low/mid latitudes, with considerable regional variations. With few exceptions, increases and decreases in fish production potential by 2050 are estimated to be <10% (mean +3.4%) from present yields. Among the nations showing a high dependency on fisheries, climate change is predicted to increase productive potential in West Africa and decrease it in South and Southeast Asia. Despite projected human population increases and assuming that per capita fish consumption rates will be maintained, ongoing technological development in the aquaculture industry suggests that projected global fish demands in 2050 could be met, thus challenging existing predictions of inevitable shortfalls in fish supply by the mid-twenty-first century. This conclusion, however, is contingent on successful implementation of strategies for sustainable harvesting and effective distribution of wild fish products from nations and regions with a surplus to those with a deficit. Changes in management effectiveness and trade practices will remain the main influence on realized gains or losses in global fish production.
The world's oceans are governed as a system of over 150 sovereign exclusive economic zones (EEZs, ∼42% of the ocean) and one large high seas (HS) commons (∼58% of ocean) with essentially open access. Many high-valued fish species such as tuna, billfish, and shark migrate around these large oceanic regions, which as a consequence of competition across EEZs and a global race-to-fish on the HS, have been over-exploited and now return far less than their economic potential. We address this global challenge by analyzing with a spatial bioeconomic model the effects of completely closing the HS to fishing. This policy both induces cooperation among countries in the exploitation of migratory stocks and provides a refuge sufficiently large to recover and maintain these stocks at levels close to those that would maximize fisheries returns. We find that completely closing the HS to fishing would simultaneously give rise to large gains in fisheries profit (>100%), fisheries yields (>30%), and fish stock conservation (>150%). We also find that changing EEZ size may benefit some fisheries; nonetheless, a complete closure of the HS still returns larger fishery and conservation outcomes than does a HS open to fishing.
Organisms are expected to adapt or move in response to climate change, but observed distribution shifts span a wide range
of directions and rates. Explanations often emphasize biological distinctions among species, but general mechanisms have been
elusive. We tested an alternative hypothesis: that differences in climate velocity—the rate and direction that climate shifts
across the landscape—can explain observed species shifts. We compiled a database of coastal surveys around North America from
1968 to 2011, sampling 128 million individuals across 360 marine taxa. Climate velocity explained the magnitude and direction
of shifts in latitude and depth much more effectively than did species characteristics. Our results demonstrate that marine
species shift at different rates and directions because they closely track the complex mosaic of local climate velocities.
Past meta-analyses of the response of marine organisms to climate change
have examined a limited range of locations, taxonomic groups and/or
biological responses. This has precluded a robust overview of the effect
of climate change in the global ocean. Here, we synthesized all
available studies of the consistency of marine ecological observations
with expectations under climate change. This yielded a meta-database of
1,735 marine biological responses for which either regional or global
climate change was considered as a driver. Included were instances of
marine taxa responding as expected, in a manner inconsistent with
expectations, and taxa demonstrating no response. From this database,
81-83% of all observations for distribution, phenology, community
composition, abundance, demography and calcification across taxa and
ocean basins were consistent with the expected impacts of climate
change. Of the species responding to climate change, rates of
distribution shifts were, on average, consistent with those required to
track ocean surface temperature changes. Conversely, we did not find a
relationship between regional shifts in spring phenology and the
seasonality of temperature. Rates of observed shifts in species'
distributions and phenology are comparable to, or greater, than those
for terrestrial systems.
This article presents the outcome of research aimed at assisting governments in meeting their commitments and legal obligations for sustainable fisheries, based on increasing evidence that global fisheries are in crisis. The article assesses the effectiveness of the existing legal and institutional framework for high seas living resources. It focuses on: (1) the role of regional fisheries management organizations (RFMOs); (2) tools for compliance and enforcement to stem illegal fishing; and (3) mechanisms for habitat protection. The article further highlights a variety of options for addressing key weaknesses and gaps in current ocean governance, including United Nations General Assembly (UNGA) resolutions, reforms at the regional level, as well as a possible new legal instrument, with a view to informing international discussions on ways to ensure the sustainable use of high seas resources without compromising the health of the marine environment.
West Africa was identified as one of the most vulnerable regions to climate change in previous global analyses. Adverse changes in marine resources under climate change may pose significant threats to the livelihoods and well-being of the communities and countries that depend on fisheries for food and income. However, quantitative studies on the potential impact of climate change on fisheries and its subsequent impact on human well-being in West Africa are still scarce. This paper aims to assess the potential impacts of climate change on fisheries and their effects on the economics, food and nutritional security in West Africa. We use a dynamic bioclimatic envelope model to project future distribution and maximum fisheries catch potential of fish and invertebrates in West African waters. Our projections show that climate change may lead to substantial reduction in marine fish production and decline in fish protein supply in this region by the 2050s under the Special Report on Emission Scenarios (SRES) A1B. Combining with economic parameters, we project a 21% drop in annual landed value, 50% decline in fisheries-related jobs and a total annual loss of US$311 million in the whole economy of West Africa. These changes are expected to increase the vulnerability of the region through economics and food security of West Africa to climate change.
Marine fishes and invertebrates respond to ocean warming through distribution shifts, generally to higher latitudes and deeper waters. Consequently, fisheries should be affected by 'tropicalization' of catch (increasing dominance of warm-water species). However, a signature of such climate-change effects on global fisheries catch has so far not been detected. Here we report such an index, the mean temperature of the catch (MTC), that is calculated from the average inferred temperature preference of exploited species weighted by their annual catch. Our results show that, after accounting for the effects of fishing and large-scale oceanographic variability, global MTC increased at a rate of 0.19 degrees Celsius per decade between 1970 and 2006, and non-tropical MTC increased at a rate of 0.23 degrees Celsius per decade. In tropical areas, MTC increased initially because of the reduction in the proportion of subtropical species catches, but subsequently stabilized as scope for further tropicalization of communities became limited. Changes in MTC in 52 large marine ecosystems, covering the majority of the world's coastal and shelf areas, are significantly and positively related to regional changes in sea surface temperature. This study shows that ocean warming has already affected global fisheries in the past four decades, highlighting the immediate need to develop adaptation plans to minimize the effect of such warming on the economy and food security of coastal communities, particularly in tropical regions.
Pacific Island countries have an extraordinary dependence on fisheries
and aquaculture. Maintaining the benefits from the sector is a difficult
task, now made more complex by climate change. Here we report how
changes to the atmosphere-ocean are likely to affect the food webs,
habitats and stocks underpinning fisheries and aquaculture across the
region. We found winners and losers--tuna are expected to be more
abundant in the east and freshwater aquaculture and fisheries are likely
to be more productive. Conversely, coral reef fisheries could decrease
by 20% by 2050 and coastal aquaculture may be less efficient. We
demonstrate how the economic and social implications can be addressed
within the sector--tuna and freshwater aquaculture can help support
growing populations as coral reefs, coastal fisheries and mariculture
decline.
Global marine fisheries are currently underperforming, largely due to overfishing. An analysis of global databases finds that resource rent net of subsidies from rebuilt world fisheries could increase from the current negative US54 billion per year, resulting in a net gain of US1,400 billion in present value over fifty years after rebuilding. To realize this gain, governments need to implement a rebuilding program at a cost of about US130-US$292) billion in present value. We estimate that it would take just 12 years after rebuilding begins for the benefits to surpass the cost. Even without accounting for the potential boost to recreational fisheries, and ignoring ancillary and non-market values that would likely increase, the potential benefits of rebuilding global fisheries far outweigh the costs.
Anthropogenic global warming has significantly influenced physical and biological processes at global and regional scales. The observed and anticipated changes in global climate present significant opportunities and challenges for societies and economies. We compare the vulnerability of 132 national economies to potential climate change impacts on their capture fisheries using an indicator-based approach. Countries in Central and Western Africa (e.g. Malawi, Guinea, Senegal, and Uganda), Peru and Colombia in north-western South America, and four tropical Asian countries (Bangladesh, Cambodia, Pakistan, and Yemen) were identified as most vulnerable. This vulnerability was due to the combined effect of predicted warming, the relative importance of fisheries to national economies and diets, and limited societal capacity to adapt to potential impacts and opportunities. Many vulnerable countries were also among the world’s least developed countries whose inhabitants are among the world’s poorest and twice as reliant on fish, which provides 27% of dietary protein compared to 13% in less vulnerable countries. These countries also produce 20% of the world’s fish exports and are in greatest need of adaptation planning to maintain or enhance the contribution that fisheries can make to poverty reduction. Although the precise impacts and direction of climate-driven change for particular fish stocks and fisheries are uncertain, our analysis suggests they are likely to lead to either increased economic hardship or missed opportunities for development in countries that depend upon fisheries but lack the capacity to adapt.
Summary • Climate change impacts have been observed on individual species and species subsets; however, it remains to be seen whether there are systematic, coherent assemblage-wide responses to climate change that could be used as a representative indicator of changing biological state. • European shelf seas are warming faster than the adjacent land masses and faster than the global average. We explore the year-by-year distributional response of North Sea bottom-dwelling (demersal) fishes to temperature change over the 25 years from 1980 to 2004. The centres of latitudinal and depth distributions of 28 fishes were estimated from species-abundance–location data collected on an annual fish monitoring survey. • Individual species responses were aggregated into 19 assemblages reflecting physiology (thermal preference and range), ecology (body size and abundance-occupancy patterns), biogeography (northern, southern and presence of range boundaries), and susceptibility to human impact (fishery target, bycatch and non-target species). • North Sea winter bottom temperature has increased by 1·6 °C over 25 years, with a 1 °C increase in 1988–1989 alone. During this period, the whole demersal fish assemblage deepened by ~3·6 m decade−1 and the deepening was coherent for most assemblages. • The latitudinal response to warming was heterogeneous, and reflects (i) a northward shift in the mean latitude of abundant, widespread thermal specialists, and (ii) the southward shift of relatively small, abundant southerly species with limited occupancy and a northern range boundary in the North Sea. • Synthesis and applications. The deepening of North Sea bottom-dwelling fishes in response to climate change is the marine analogue of the upward movement of terrestrial species to higher altitudes. The assemblage-level depth responses, and both latitudinal responses, covary with temperature and environmental variability in a manner diagnostic of a climate change impact. The deepening of the demersal fish assemblage in response to temperature could be used as a biotic indicator of the effects of climate change in the North Sea and other semi-enclosed seas.
Tunas and their relatives dominate the world's largest ecosystems and sustain some of the most valuable fisheries. The impacts of fishing on these species have been debated intensively over the past decade, giving rise to divergent views on the scale and extent of the impacts of fisheries on pelagic ecosystems. We use all available age-structured stock assessments to evaluate the adult biomass trajectories and exploitation status of 26 populations of tunas and their relatives (17 tunas, 5 mackerels, and 4 Spanish mackerels) from 1954 to 2006. Overall, populations have declined, on average, by 60% over the past half century, but the decline in the total adult biomass is lower (52%), driven by a few abundant populations. The trajectories of individual populations depend on the interaction between life histories, ecology, and fishing pressure. The steepest declines are exhibited by two distinct groups: the largest, longest lived, highest value temperate tunas and the smaller, short-lived mackerels, both with most of their populations being overexploited. The remaining populations, mostly tropical tunas, have been fished down to approximately maximum sustainable yield levels, preventing further expansion of catches in these fisheries. Fishing mortality has increased steadily to the point where around 12.5% of the tunas and their relatives are caught each year globally. Overcapacity of these fisheries is jeopardizing their long-term sustainability. To guarantee higher catches, stabilize profits, and reduce collateral impacts on marine ecosystems requires the rebuilding of overexploited populations and stricter management measures to reduce overcapacity and regulate threatening trade.
Determining the distribution of the conservation burden and benefit is a critical challenge to the conservation and management of trans-boundary fish stocks. Given current levels of overfishing and overcapacity in many trans-boundary fisheries, some or all participating States must necessarily reach a compromise with regard to their interests and carry some share of the conservation burden. This article proposes a new approach to distributing the conservation burden and benefit in trans-boundary fisheries, and explores this approach in the world's largest tuna fishery: the tropical tuna fisheries of the western and central Pacific. Such an approach would enable Regional Fisheries Management Organizations (RFMOs) to transparently ensure that conservation burden and benefit distributions are consistent with international obligations. The article recommends that RFMOs consider developing decision-making frameworks that would enable existing scientific processes to determine the necessary extent of conservation measures, while a new conservation burden methodology would then determine the implementation of the measure and its impact on each member.
The 1982 United Nations Convention on the Law of the Sea and its 1995 implementing agreement for highly migratory and straddling fish stocks (the UN Fish Stocks Agreement) articulate the need for * Acknowledgments: We appreciate the support of sponsors for the Stanford Law School Symposium Emerging Perspectives on the Law, Science, and Policy of Dynamic Marine Conservation. We further extend great appreciation to Martin Hall for his advice and input throughout the drafting of this article. We also thank two anonymous reviewers for their helpful comments and edits.
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.
Marine biological resources are likely to come under increasing stress over the course of the 21st century as global climate change and ocean acidification interact with other stresses, including heavy fishing pressures and marine pollution, to create far reaching and difficult-to-predict changes in species abundance, spatial distribution, and trophic interactions. The governance systems in place for marine fisheries and for the marine environment, more broadly, will be critical in determining the extent to which these resources can be managed for sustainability. The paper focuses on the governance of internationally shared fisheries, and draws on a body of game-theoretic research to discuss present-day governance problems and to evaluate the implications of global environmental change for future efforts to maintain cooperative and effective governance of shared fishery resources. In particular, the increased likelihood of abrupt and unpredictable changes in the productive potential and migratory behavior of exploited fish stocks may threaten to disrupt cooperative management arrangements. The paper discusses the value of contingency planning based on anticipation of the possibility of such events and concludes with a discussion of future directions for both research and policy development.
Biodiversity has been recognized as one of the key components of environmental sustainability. Assessment of biodiversity trends and progress toward targets requires effective and sound indicators. In our article, we review and compare the leading multispecies biodiversity indices used in global and regional assessments. We reviewed basic characteristics of these aggregated and composite biodiversity indicators and evaluated them with regard to their ecological performance, policy relevance and other accounting aspects. Indices analyzed include species and populations based indicators, such as Living Planet Index and Red List Index, as well as ecosystem based indicators like Natural Capital Index and Biodiversity Intactness Index. We also include measures of ecological integrity such as Marine Trophic Index and Index of Biotic Integrity. Indicators analyzed differ in both their ecological focus, baselines, basic units or policy use. Multispecies biodiversity indices illustrate prevailingly negative trends in the state of nature as a result of human induced pressures, especially land cover change. Biodiversity loss is therefore not decoupled from socioeconomic progress. We show that current indicators include a balanced mix of important biodiversity aspects and have some policy resonance. Leading biodiversity indices should be further promoted and integrated into monitoring, modelling and decision-making frameworks.
Regional fisheries management organizations (RFMOs) collectively manage the largest distinct area of the world, the high seas, but their effectiveness in conserving the fish stocks therein has been questioned lately, as many stocks have declined. This study quantitatively assesses the effectiveness of the world's 18 RFMOs, based on a two-tiered approach, concentrating first on their performance ‘on paper’ and secondly, in practice. The former was determined by assessing how well RFMOs scored against 26 criteria that together reflect current RFMO best practices. The latter assessment referenced the current state of the stocks RFMOs manage, through biomass and fishing mortality reference points and biomass trends through time. Results show low performance of RFMOs for both assessments, i.e., average scores of 57% and 49%, respectively. The latter result is emphasized by findings that reflect two-thirds of stocks fished on the high seas and under RFMO management are either depleted or overexploited. Findings also indicate that there is no connection between the two sets of scores, suggesting a disparity between organization intent and action.
The High Seas and Us: Understanding the Value of High-Seas Ecosystems
- A Rogers
- U Sumaila
- S Hussain
- C Baulcomb
Rogers, A., Sumaila, U., Hussain, S. and Baulcomb, C.
(2014) The High Seas and Us: Understanding the Value of
High-Seas Ecosystems.Report, Global Ocean Commission, Somerville College, Oxford, 23 pp.
Review of multispecies indices for monitoring human impacts on biodiversity
- U R Sumaila
- V W Y Lam
- D D Miller
Sumaila, U.R., Lam, V.W.Y., Miller, D.D. et al. (2015)
Winners and losers in a world where the high seas is
closed to fishing. Scientific Reports 5, 8481.
Va ck a r, D., ten Brink, B., Loh, J., Baillie, J.E. and Reyers,
B. (2012) Review of multispecies indices for monitoring human impacts on biodiversity. Ecological Indicators
17, 58-67.
The High Seas and Us: Understanding the Value of High-Seas Ecosystems
- Rogers A Sumaila
- U Hussain