Global trade network patterns are coupled to fisheries sustainability

Laura G Elsler; Maartje Oostdijk; Jessica A Gephart; Christopher M Free; Junfu Zhao; Eden Tekwa; Elaine M Bochniewicz; Alfredo Giron-Nava; Andrew F Johnson

doi:10.1093/pnasnexus/pgad301

Global trade network patterns are coupled to fisheries sustainability

PNAS Nexus. 2023 Sep 16;2(10):pgad301. doi: 10.1093/pnasnexus/pgad301. eCollection 2023 Oct.

Authors

Affiliations

¹ Stockholm Resilience Centre, Stockholm University, 11419 Stockholm, Sweden.
² School of Environment and Natural Resources, University of Iceland, 101 Reykjavik, Iceland.
³ Department of Environmental Science, American University, Washington, DC 20016, USA.
⁴ Bren School of Environmental Science and Management, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
⁵ Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
⁶ Institute of Marxism, Fudan University, Shanghai 200433, China.
⁷ Department of Biology, McGill University, Montreal, QC H3A 1B1, Canada.
⁸ The MITRE Corporation, McLean, VA 22102, USA.
⁹ Stanford Center for Ocean Solutions, Stanford University, Palo Alto, CA 94305, USA.
¹⁰ Marine SPACE group, The Lyell Centre, Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Edinburgh, Currie, Scotland EH14 4AS, UK.
¹¹ MarFishEco Fisheries Consultants Ltd., Edinburgh, Scotland EH7 5HT, UK.

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.

Keywords: marine fisheries; network analysis; resilience; seafood trade; serial exploitation; stock status assessment.