Modeling the impacts of floating seaweeds on fisheries sustainability in Ghana

Document Type

Article

Publication Date

5-2021

Department

Department of Social Sciences

Abstract

The ongoing Sargassum invasions in the Atlantic Ocean present both opportunities and threats to open-access fisheries. Due to the lack of entry and harvest regulations, West African fisheries are on the verge of collapse. Floating seaweeds can help rebuild fish stocks by enhancing fish growth and naturally reducing harvest by impeding fishing boats and gears. However, in high volumes, floating seaweeds can harm fish stocks and reduce landings. To improve fisheries sustainability, a policy prescribing the periodic removal of seaweeds should be anchored on a thorough understanding of the trade-offs between different levels of seaweed removal. We developed an agent-based model (ABM) to identify the optimal seaweed removal policy capable of maximizing fish stocks and landings in the long-term in Ghana's marine fishery. Our policy experiments suggest that, by leaving behind 25% of relative seaweed biomass (i.e. seaweed biomass expressed as a percentage of carrying capacity) in each fishing zone every week after seaweed removal, fishery managers can take advantage of floating seaweeds to naturally regulate fishing mortality and maximize fish stocks and landings in the long-term. Our ABM can assist scientists interested in studying the long-term interactions between floating seaweeds and fisheries sustainability, and help fishery managers understand the potential of floating seaweeds to naturally regulate fishing pressure in developing countries where the lack of adequate employment opportunities outside fishing makes it difficult to address overfishing. Our ABM can also assist countries struggling with seaweed invasions to assess the impacts of different seaweed removal strategies on fisheries sustainability.

Publisher's Statement

© 2021 Elsevier Ltd. Publisher’s version of record: https://doi.org/10.1016/j.marpol.2021.104427

Publication Title

Marine Policy

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