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Protecting the Global Ocean for Biodiversity, Food and Climate

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Protecting the Global Ocean for Biodiversity, Food and Climate Article Protecting the global ocean for biodiversity, food and climate https://doi.org/10.1038/s41586-021-03371-z Enric Sala1 ✉, Juan Mayorga1,2, Darcy Bradley2, Reniel B. Cabral2, Trisha B. Atwood3, Arnaud Auber4, William Cheung5, Christopher Costello2, Francesco Ferretti6, Received: 19 December 2019 Alan M. Friedlander1,7, Steven D. Gaines2, Cristina Garilao8, Whitney Goodell1,7, Accepted: 18 February 2021 Benjamin S. Halpern9, Audra Hinson3, Kristin Kaschner8, Kathleen Kesner-Reyes10, Fabien Leprieur11, Jennifer McGowan12, Lance E. Morgan13, David Mouillot11, Published online: xx xx xxxx Juliano Palacios-Abrantes5, Hugh P. Possingham14, Kristin D. Rechberger15, Boris Worm16 & Check for updates Jane Lubchenco17 The ocean contains unique biodiversity, provides valuable food resources and is a major sink for anthropogenic carbon. Marine protected areas (MPAs) are an efective tool for restoring ocean biodiversity and ecosystem services1,2, but at present only 2.7% of the ocean is highly protected3. This low level of ocean protection is due largely to conficts with fsheries and other extractive uses. To address this issue, here we developed a conservation planning framework to prioritize highly protected MPAs in places that would result in multiple benefts today and in the future. We fnd that a substantial increase in ocean protection could have triple benefts, by protecting biodiversity, boosting the yield of fsheries and securing marine carbon stocks that are at risk from human activities. Our results show that most coastal nations contain priority areas that can contribute substantially to achieving these three objectives of biodiversity protection, food provision and carbon storage. A globally coordinated efort could be nearly twice as efcient as uncoordinated, national-level conservation planning. Our fexible prioritization framework could help to inform both national marine spatial plans4 and global targets for marine conservation, food security and climate action. The global ocean is a trove of biodiversity, containing unique life forms can simultaneously yield benefits for biodiversity conservation, food and genetic resources that provide ecosystem services of enormous provisioning and carbon storage. value to humans2,5. However, increasing anthropogenic effects are Previous efforts to identify global conservation priorities in the compromising the ability of the ocean to provide these services6,7 and ocean have primarily focused on narrow definitions of biodiversity have motivated a global discussion about expanding the world’s system and ignored other key facets such as functional roles, evolutionary of MPAs. histories of species and unique community assemblages12,13. Perhaps MPAs—especially highly protected areas in which extractive and more importantly, focusing on a single objective in a multi-use ocean destructive activities are banned8,9—can be effective management tools often results in strong trade-offs that hinder real-world conservation to safeguard and restore ocean biodiversity and associated services1,2,10, action. To overcome these problems, we developed a comprehensive complement conventional fisheries management and contribute to the conservation planning framework to achieve multiple objectives: mitigation of climate change by protecting marine carbon stocks11. Yet biodiversity protection, food provisioning and carbon storage. The as of March 2021, only around 7% of ocean area has been designated framework considers human impacts that are abatable through highly or proposed as MPAs, and only 2.7% is actually implemented as fully or fully protected MPAs (that is, protection from fishing, mining and or highly protected3. This low level of ocean protection is explained habitat destruction) and those that are un-abatable with those tools14 in part by conflict between protection and extraction stemming from (for example, nutrient pollution, ocean warming and acidification), perceived trade-offs. Rather than viewing protection versus extraction and it seeks to maximize the difference made by protection relative as a zero-sum game, we ask whether strategic conservation planning to a business-as-usual scenario (that is, a world without additional 1Pristine Seas, National Geographic Society, Washington, DC, USA. 2Environmental Market Solutions Lab, University of California Santa Barbara, Santa Barbara, CA, USA. 3Department of Watershed Sciences and Ecology Center, Utah State University, Logan, UT, USA. 4IFREMER, Unité Halieutique de Manche et Mer du Nord, Boulogne-sur-Mer, France. 5Changing Ocean Research Unit, Institute for the Oceans and Fisheries, The University of British Columbia, Vancouver, British Columbia, Canada. 6Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA. 7Hawai‘i Institute of Marine Biology, Kāne‘ohe, HI, USA. 8Evolutionary Biology and Ecology Laboratory, Albert Ludwigs University, Freiburg, Germany. 9National Center for Ecological Analysis and Synthesis (NCEAS), University of California, Santa Barbara, CA, USA. 10Quantitative Aquatics, Los Baños, The Philippines. 11MARBEC, Université de Montpellier, Montpellier, France. 12The Nature Conservancy, Arlington, VA, USA. 13Marine Conservation Institute, Seattle, WA, USA. 14Centre for Biodiversity and Conservation Science (CBCS), The University of Queensland, Brisbane, Queensland, Australia. 15Dynamic Planet, Washington, DC, USA. 16Ocean Frontiers Institute, Dalhousie University, Halifax, Nova Scotia, Canada. 17Oregon State University, Corvallis, OR, USA. ✉e-mail: [email protected] Nature | www.nature.com | 1 Article a c e Top per cent of the ocea 50 40 30 20 15 10 5 n 0 b d f 1.6 5 Global 1.00 Change in catch (MMT) 1.00 0 0 EEZs 1.2 High seas 0.75 −10 0.75 CO −2 2 0.8 (Pg) 0.50 vision benet −20 0.50 ersity benet −4 0.25 −30 Carbon benet 0.25 0.4 Biodiv ood pro F −6 0 −40 0 0 0 0.25 0.50 0.75 1.00 0 0.25 0.50 0.75 1.00 0 0.25 0.50 0.75 1.00 Fraction of ocean protected Fraction of ocean protected Fraction of ocean protected Fig. 1 | Global conservation priorities. a, c, e, Prioritization of a global provisioning) (d) and reduction of the risk of carbon disturbance due to network of MPAs for biodiversity conservation (a), food provisioning (c) and bottom trawling (for carbon) (f). Cumulative global benefits and those carbon stocks (e). Existing fully protected areas are shown in light blue. b, d, f, accruing from protection of the high seas and EEZs are shown separately. The Corresponding cumulative benefit functions, in which ‘benefits’ are defined as blue bar in the benefit curves denotes the current 2.7% of the global ocean that conservation gains (for biodiversity) (b), net change in the catchable species of is included in fully protected areas. fisheries owing to spillover from marine protected areas (for food protection). Furthermore, it does not require area-based targets set Climate change is already modifying the distributions of marine a priori, but instead produces a hierarchy of marine conservation pri- species and is expected to continue to do so17. Hence the biodiversity orities across scales. benefits of any MPA network that is designed for current conditions may change in the future18. To assess these putative changes, we re-assess our biodiversity prioritization using projected species distributions Biodiversity conservation for 2050 under a ‘high greenhouse gas emissions’ scenario (Intergov- Marine biodiversity is the variety of life in the sea, encompassing vari- ernmental Panel on Climate Change (IPCC) Special Report on Emissions ation at many levels of complexity, from within taxa to ecosystems. Scenarios (SRES) A219–21; see Methods). We find that around 80% of Thus, we sought to identify areas where MPAs would be most effec- areas that are within the top 10% global biodiversity priorities today tive at achieving multiple biodiversity conservation goals, including will remain so in 2050 (Supplementary Fig. 5). Some temperate regions minimizing species extinction risk, maintaining diverse species traits and parts of the Arctic would rank as higher priorities for biodiversity in ecosystems, and preserving the evolutionary history of marine life, conservation by 2050, whereas large areas in the high seas between while ensuring biogeographical representation. To this end, we define the tropics and areas in the Southern Hemisphere would decrease in the biodiversity benefit of a given network of MPAs as the weighted sum priority. of the marginal gain in persistence of specific biodiversity features resulting from the removal of abatable impacts relative to business as usual15 (see Methods). Food provisioning Our results show that priority areas for biodiversity conservation In highly and fully protected MPAs, the biomass of commercially are distributed throughout the ocean, with 90% of the top 10% priority targeted fishes and invertebrates increases over time, and given the areas contained within the 200-mile exclusive economic zones (EEZs) right biological conditions, may also enhance productivity in fished administered by individual coastal nations (Fig. 1a). These EEZs are areas outside of the MPA through adult and larval spillover22–24. Where home to irreplaceable biodiversity and are often heavily affected by overfishing is occurring, MPAs can increase food provisioning; where human activities that can be abated by MPAs16 (Supplementary Fig. 1). fisheries are well-managed or exploited below the maximum sustain- However, we also find many priority areas in the
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