Northwest Fisheries Science Center

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Document Type: Journal Article
Center: NWFSC
Document ID: 8652
Title: Pretty good multispecies yield
Author: Anna Rindorf, Catherine M. Dichmont, P. S. Levin, P. M. Mace, Sean Pascoe, Raul Prellezo, A. E. Punt, David Reid, R. Stephenson, Clara Ulrich, Morten Vinther, Lotte Worsoe Clausen
Publication Year: 2016
Journal: ICES Journal of Marine Science
DOI: 10.1093/icesjms/fsw071
Keywords: MSY,MEY,Ecosystem base management,social objectives
Abstract:

MSY-principles for marine fisheries management reflect a focus on obtaining continuing high catches to provide food and livelihoods to humanity, while not compromising ecosystems. However, maintaining healthy stocks to provide the Maximum Sustainable Yield on a single species basis does not ensure that broader ecosystem, economic and social objectives are addressed. We investigate how the principles of a Pretty Good Yield range of fishing mortalities assumed to provide more than 95% of the average yield for a single stock can be expanded to a Pretty Good Multispecies Yield (PGMY) space and further to pretty good multidimensional yield to accommodate situations where the yield from a stock affects the ecosystem, economic and social benefits or sustainability. We demonstrate in a European example that PGMY is a practical concept that can address some ecosystem, economic and social trade-offs encountered in different parts of the PGMY space.  As PGMY provides a safe operating space for management that adheres to the principles of MSY, it allows the consideration of other aspects to be included in operational management advice in both data-rich and data-limited situations. PGMY furthermore provides a way to integrate advice across stocks, avoiding clearly infeasible management combinations and thereby hopefully increasing confidence in scientific advice.

Description:

MSY-principles for marine fisheries management reflect a focus on obtaining continuing high catches to provide food and livelihoods to humanity, while not compromising ecosystems. However, maintaining healthy stocks to provide the Maximum Sustainable Yield on a single species basis does not ensure that broader ecosystem, economic and social objectives are addressed. We investigate how the principles of a Pretty Good Yield range of fishing mortalities assumed to provide more than 95% of the average yield for a single stock can be expanded to a Pretty Good Multispecies Yield (PGMY) space and further to pretty good multidimensional yield to accommodate situations where the yield from a stock affects the ecosystem, economic and social benefits or sustainability. We demonstrate in a European example that PGMY is a practical concept that can address some ecosystem, economic and social trade-offs encountered in different parts of the PGMY space.  As PGMY provides a safe operating space for management that adheres to the principles of MSY, it allows the consideration of other aspects to be included in operational management advice in both data-rich and data-limited situations. PGMY furthermore provides a way to integrate advice across stocks, avoiding clearly infeasible management combinations and thereby hopefully increasing confidence in scientific advice.

Theme: Ecosystem approach to improve management of marine resources
Foci: Provide scientific support for the implementation of ecosystem-based management