Standard Presentation Australian Marine Sciences Association Annual Meeting 2023

Does Larval Export From Protected Areas Offset Lost Fishing? (#143)

Sandra Neubert 1 2 , Kim Scherrer 3 4 , Jason D Everett 2 5 6 , Ryan Heneghan 7 , Daniel E Hewitt 6 , Arthur Blanluet 2 8 , Peter F Stadler 9 , Anthony J Richardson 2 5
  1. Institute of Computer Science, Leipzig University, Leipzig, Germany
  2. School of Mathematics and Physics, University of Queensland, St Lucia, QLD, Australia
  3. Institut de Ciència i Tecnologia Ambientals, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
  4. Department of Biological Sciences, University of Bergen, Bergen, Norway
  5. Commonwealth Scientific and Industrial Research Organization (CSIRO) Environment, St Lucia, QLD, Australia
  6. Centre for Marine Science and Innovation (CMSI), The University of New South Wales, Sydney, NSW, Australia
  7. School of Mathematical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
  8. The Nature Conservancy, South Brisbane, QLD, Australia
  9. Bioinformatics Group, Department of Computer Science & Interdisciplinary Center for Bioinformatics, Leipzig University, Leipzig, Germany

In response to growing concerns about anthropogenic threats to marine ecosystems, there are calls for an expansion of marine protected area (MPA) coverage to 30% by 2030 (30✕30). Although MPA implementation is commonly associated with economic costs to fisheries, MPAs have been suggested as a management tool to sustain fisheries through adult spillover and the passive export of eggs and larvae. Here, we assess whether larval export reduces the cost to fisheries associated with implementing MPAs. We couple Lagrangian particle tracking to simulate larval movement with a global marine ecosystem model to estimate fish biomass and harvest. We then explore two 30✕30 scenarios maximising either biodiversity or economic benefit and test whether larval movement from MPAs could offset the projected loss to fisheries of the MPA. Larval export increased fisheries catch close to MPA borders but had a relatively small impact on catch globally. This effect was greater in the scenario maximising biodiversity since there were larger larval exports due to higher biomass within the MPAs, and a higher initial cost to fisheries. We hope that this global analysis of the impacts of larval exports from MPAs on fisheries catch can inform the debate about the potential benefit of MPAs.