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Comparative production of fisheries yields and ecosystem overfishing in African Large Marine Ecosystems


Link, JS and Watson, RA and Pranovi, F and Libralato, S, Comparative production of fisheries yields and ecosystem overfishing in African Large Marine Ecosystems, Environmental Development, 36 Article 100529. ISSN 2211-4645 (2020) [Refereed Article]

Copyright Statement

Copyright 2020 Elsevier

DOI: doi:10.1016/j.envdev.2020.100529


Marine capture fisheries in African Large Marine Ecosystems (LMEs) are important from economic, cultural, social, and food provision perspectives. These African fisheries have a long history of high exploitation in the context of data-limited situations. There is a growing, global movement (both in terms of management requirements and scientific efforts) to develop measures of ecosystem overfishing (EOF) that detect overfishing of an entire ecosystem using readily available data and based on widely repeatable patterns. These EOF indicators extend the thinking beyond single stock overfishing to an entire ecosystem and are largely based on well-established trophic theory. Moreover, they need to be germane for data limited situations, easily interpretable, and simple to calculate. Here we introduce and present the results of several of these indicators—the Ryther index, Fogarty index, and Friedland index—as well as indices based on cumulative biomass-Trophic Level curve parameters for eight African LMEs. Significantly, all these EOF indicators also have thresholds beyond which EOF is indicated, particularly when coupled with other evidence. These thresholds were applied to the African LME EOF indicators to determine the degree to which EOF may be occurring. Five out of eight African LMEs exhibited symptoms of EOF, one with significant EOF, with at least one LME still currently experiencing EOF, and three more that may be close to EOF thresholds. One LME exhibited evidence of recovering trends. Additionally, EOF indicators detected changes in the LMEs five-ten years prior to major impacts that would be identified by piecing together fishing impacts on a stock-by-stock basis. We conclude that if EOF is detected, at the very least these relative simple measures should be monitored and means to mitigate total fishing pressure in an ecosystem should be explored.

Item Details

Item Type:Refereed Article
Keywords:systematic overfishing, thresholds, food security, fisheries ecosystem, comparative analysis, integrative metrics, food security, Atlantic ocean, Indian ocean
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Fisheries sciences
Research Field:Fisheries sciences not elsewhere classified
Objective Division:Animal Production and Animal Primary Products
Objective Group:Environmentally sustainable animal production
Objective Field:Environmentally sustainable animal production not elsewhere classified
UTAS Author:Watson, RA (Professor Reginald Watson)
ID Code:141928
Year Published:2020
Web of Science® Times Cited:10
Deposited By:Fisheries and Aquaculture
Deposited On:2020-12-03
Last Modified:2021-02-22

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