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Elsler LG, Oostdijk M, Gephart JA, Free CM, Zhao J, Tekwa E, Bochniewicz EM, Giron-Nava A, Johnson AF. Global trade network patterns are coupled to fisheries sustainability. PNAS NEXUS 2023; 2:pgad301. [PMID: 37817775 PMCID: PMC10560747 DOI: 10.1093/pnasnexus/pgad301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 07/12/2023] [Accepted: 08/31/2023] [Indexed: 10/12/2023]
Abstract
The rapid development of seafood trade networks alongside the decline in biomass of many marine populations raises important questions about the role of global trade in fisheries sustainability. Mounting empirical and theoretical evidence shows the importance of trade development on commercially exploited species. However, there is limited understanding of how the development of trade networks, such as differences in connectivity and duration, affects fisheries sustainability. In a global analysis of over 400,000 bilateral trade flows and stock status estimates for 876 exploited fish and marine invertebrates from 223 territories, we reveal patterns between seafood trade network indicators and fisheries sustainability using a dynamic panel regression analysis. We found that fragmented networks with strong connectivity within a group of countries and weaker links between those groups (modularity) are associated with higher relative biomass. From 1995 to 2015, modularity fluctuated, and the number of trade connections (degree) increased. Unlike previous studies, we found no relationship between the number or duration of trade connections and fisheries sustainability. Our results highlight the need to jointly investigate fisheries and trade. Improved coordination and partnerships between fisheries authorities and trade organizations present opportunities to foster more sustainable fisheries.
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Affiliation(s)
- Laura G Elsler
- Stockholm Resilience Centre, Stockholm University, 11419 Stockholm, Sweden
| | - Maartje Oostdijk
- School of Environment and Natural Resources, University of Iceland, 101 Reykjavik, Iceland
| | - Jessica A Gephart
- Department of Environmental Science, American University, Washington, DC 20016, USA
| | - Christopher M Free
- Bren School of Environmental Science and Management, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
- Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Junfu Zhao
- Institute of Marxism, Fudan University, Shanghai 200433, China
| | - Eden Tekwa
- Department of Biology, McGill University, Montreal, QC H3A 1B1, Canada
| | | | - Alfredo Giron-Nava
- Stanford Center for Ocean Solutions, Stanford University, Palo Alto, CA 94305, USA
| | - Andrew F Johnson
- Marine SPACE group, The Lyell Centre, Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Edinburgh, Currie, Scotland EH14 4AS, UK
- MarFishEco Fisheries Consultants Ltd., Edinburgh, Scotland EH7 5HT, UK
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Kindong R, Wu F, Sarr O, Zhu J. A simulation-based option to assess data-limited fisheries off West African waters. Sci Rep 2023; 13:15290. [PMID: 37714923 PMCID: PMC10504299 DOI: 10.1038/s41598-023-42521-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 09/11/2023] [Indexed: 09/17/2023] Open
Abstract
Most sophisticated stock assessment models often need a large amount of data to assess fish stocks, yet this data is often lacking for most fisheries worldwide, resulting in the increasing demand for data-limited stock assessment methods. To estimate fish stock status, one class of these data-limited methods uses simply catch time series data and, in other instances, life history information or fishery characteristics. These catch-only methods (COMs) built differently are known to make assumptions about changes in fishing effort and may perform differently under various fishing scenarios. As a case study, this paper used European anchovy (Engraulis encrasicolus) caught in the northwest African waters, though very economically and ecologically important, but still unassessed. Our study investigated the performance of five COMs under different fishing scenarios using as a reference the life-history information of the European anchovy captured in this region of the Atlantic. Hence, the present study developed a simulation approach to evaluate the performance of the five COMs in inferring the stock biomass status (B/BMSY) with consideration of different fishing scenarios under prior information true to anchovy. All five COMs mostly underestimated B/BMSY throughout the simulation period, especially under constant fishing mortality, and in the last five years of the simulation during all fishing scenarios. Overall, these COMs were generally poor classifiers of stock status, however, the state-space COM (SSCOM) generally performed better than the other COMs as it showed possibilities of recovering an overfished stock. When these methods were explored using actual anchovy catch data collected in the northwest African waters, SSCOM yielded results that were deferred from the other COMs. This study being the first to assess this species' stock in this area using a suite of COMs, presents more insights into the species stock status, and what needs to be considered before scientifically putting in place management measures of the stock in the area.
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Affiliation(s)
- Richard Kindong
- College of Marine Sciences, Shanghai Ocean University, Shanghai, 201306, China.
- Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources, Ministry of Education, Shanghai, 201306, China.
- Key Laboratory of Oceanic Fisheries Exploration, Ministry of Agriculture and Rural Affairs, Shanghai, 201306, China.
- National Engineering Research Centre for Oceanic Fisheries, Shanghai Ocean University, Shanghai, China.
| | - Feng Wu
- College of Marine Sciences, Shanghai Ocean University, Shanghai, 201306, China
- Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources, Ministry of Education, Shanghai, 201306, China
- Key Laboratory of Oceanic Fisheries Exploration, Ministry of Agriculture and Rural Affairs, Shanghai, 201306, China
- National Engineering Research Centre for Oceanic Fisheries, Shanghai Ocean University, Shanghai, China
| | - Ousmane Sarr
- College of Marine Sciences, Shanghai Ocean University, Shanghai, 201306, China
| | - Jiangfeng Zhu
- College of Marine Sciences, Shanghai Ocean University, Shanghai, 201306, China.
- Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources, Ministry of Education, Shanghai, 201306, China.
- Key Laboratory of Oceanic Fisheries Exploration, Ministry of Agriculture and Rural Affairs, Shanghai, 201306, China.
- National Engineering Research Centre for Oceanic Fisheries, Shanghai Ocean University, Shanghai, China.
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Free CM, Mangin T, Molinos JG, Ojea E, Burden M, Costello C, Gaines SD. Realistic fisheries management reforms could mitigate the impacts of climate change in most countries. PLoS One 2020; 15:e0224347. [PMID: 32134926 PMCID: PMC7058327 DOI: 10.1371/journal.pone.0224347] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 02/06/2020] [Indexed: 12/18/2022] Open
Abstract
Although climate change is altering the productivity and distribution of marine fisheries, climate-adaptive fisheries management could mitigate many of the negative impacts on human society. We forecast global fisheries biomass, catch, and profits to 2100 under three climate scenarios (RCPs 4.5, 6.0, 8.5) and five levels of management reform to (1) determine the impact of climate change on national fisheries and (2) quantify the national-scale benefits of implementing climate-adaptive fisheries reforms. Management reforms accounting for shifting productivity and shifting distributions would yield higher catch and profits in the future relative to today for 60–65% of countries under the two least severe climate scenarios but for only 35% of countries under the most severe scenario. Furthermore, these management reforms would yield higher cumulative catch and profits than business-as-usual management for nearly all countries under the two least severe climate scenarios but would yield lower cumulative catch for 40% of countries under the most severe scenario. Fortunately, perfect fisheries management is not necessary to achieve these benefits: transboundary cooperation with 5-year intervals between adaptive interventions would result in comparable outcomes. However, the ability for realistic management reforms to offset the negative impacts of climate change is bounded by changes in underlying biological productivity. Although realistic reforms could generate higher catch and profits for 23–50% of countries experiencing reductions in productivity, the remaining countries would need to develop, expand, and reform aquaculture and other food production sectors to offset losses in capture fisheries. Still, climate-adaptive management is more profitable than business-as-usual management in all countries and we provide guidance on implementing–and achieving the benefits of–climate-adaptive fisheries reform along a gradient of scientific, management, and enforcement capacities.
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Affiliation(s)
- Christopher M. Free
- Bren School of Environmental Science & Management, University of California, Santa Barbara, Santa Barbara, California, United States of America
- * E-mail:
| | - Tracey Mangin
- Bren School of Environmental Science & Management, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Jorge García Molinos
- Arctic Research Center, Hokkaido University, Sapporo, Japan
- Global Station for Arctic Research, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Japan
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan
| | - Elena Ojea
- Future Oceans Lab, CIM-UVigo, University of Vigo, Vigo, Spain
| | - Merrick Burden
- Environmental Defense Fund, New York, New York, United States of America
| | - Christopher Costello
- Bren School of Environmental Science & Management, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Steven D. Gaines
- Bren School of Environmental Science & Management, University of California, Santa Barbara, Santa Barbara, California, United States of America
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Abstract
Marine fish stocks are an important part of the world food system and are particularly important for many of the poorest people of the world. Most existing analyses suggest overfishing is increasing, and there is widespread concern that fish stocks are decreasing throughout most of the world. We assembled trends in abundance and harvest rate of stocks that are scientifically assessed, constituting half of the reported global marine fish catch. For these stocks, on average, abundance is increasing and is at proposed target levels. Compared with regions that are intensively managed, regions with less-developed fisheries management have, on average, 3-fold greater harvest rates and half the abundance as assessed stocks. Available evidence suggests that the regions without assessments of abundance have little fisheries management, and stocks are in poor shape. Increased application of area-appropriate fisheries science recommendations and management tools are still needed for sustaining fisheries in places where they are lacking.
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