Assessing indirect biodiversity conservation benefits of fisheries closures in the Gulf of St. Lawrence, Canada

RESEARCH ARTICLE Assessing indirect biodiversity conservation benefits of fisheries closures in the Gulf of St. Lawrence, Canada Andrea Bryndum-BuchholzID*, Tyler D. EddyID, Jonathan A. D. Fisher Centre for Fisheries Ecosystems Research, Fisheries and Marine Institute of Memorial University, St John’s, Newfoundland and Labrador, Canada * andrea.buchholz@mi.mun.ca Abstract Marine biodiversity loss is a pressing global issue, intensified by human activities and cli- mate change. Complementary to marine protected areas (MPAs), Other Effective Area- Based Conservation Measures (OECMs) have emerged as a key tool to mitigate this loss by providing long-term biodiversity protection. However, while OECMs primarily target spe- cific taxa, they can also offer indirect biodiversity conservation benefits (BCBs) to a wider range of taxa. In this study, we assess the indirect BCBs of eleven OECMs in the Gulf of St. Lawrence, focusing on their role in supporting the life-history processes of commercially important species such as Atlantic halibut, Greenland halibut, and redfish. We apply an inte- grated assessment that combines knowledge and data previously unconnected to provide information to support OECM management. Our analysis reveals that eight of the eleven OECMs overlap with potential spawning habitats for these species, suggesting important life-history benefits. However, projected climate-driven changes in bottom temperature, oxy- gen concentration, and pH levels pose a threat to these habitats, potentially undermining

the long-term effectiveness of OECMs. These findings underscore the need for adaptive management strategies that incorporate climate-informed ecosystem indicators and broaden the conservation focus beyond economically important species. Such approaches are crucial to ensuring that OECMs continue to provide both direct and indirect BCBs in the face of accelerating climate change, thereby contributing to global marine biodiversity con- servation efforts. Introduction Marine biodiversity loss is a critical global concern, particularly in a world of rapid environ- mental changes driven by human activities and climate change [1, 2]. To address this issue, international agreements have pledged to protect 30% of the ocean by 2030 (the 30x30 agenda) [3]. Among the tools, developed to address this challenge are Marine Protected Areas (MPAs), Marine Reserves, and Other Effective Area-Based Conservation Measures (OECMs) [4]. While MPAs are specifically designed to protect biodiversity, OECMs are not designed to do, PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0316754 January 9, 2025 1 / 20 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Bryndum-Buchholz A, Eddy TD, Fisher JAD (2025) Assessing indirect biodiversity conservation benefits of fisheries closures in the Gulf of St. Lawrence, Canada. PLoS ONE 20(1): e0316754. https://doi.org/10.1371/journal. pone.0316754 Editor: Rubeena K. Abdulsalam, King Fahd University of Petroleum & Minerals, SAUDI ARABIA Received: October 4, 2024 Accepted: December 16, 2024 Published: January 9, 2025

Copyright: © 2025 Bryndum-Buchholz et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: No new data was produced as part of this manuscript. All relevant data are within the manuscript and its Supporting information files. All data analyzed is publicly available and cited in the manuscript (Table 2). The specific values behind the means and other measures reported in Figs 2–4 and Figs SB-SF can be accessed via https://doi.org/10.5281/zenodo. 14361460.