Evaluating alternative rebuilding plans for mixed stock fisheries

Abstract

Rebuilding overfished stocks is central to fisheries policy, with the United States Magnuson-Stevens Act aligning with the United Nations Sustainable Development Goal 14.4 “to restore fish stocks in the shortest time feasible at least to levels that can produce maximum sustainable yield.” In mixed stock fisheries, very low allowable catches for rebuilding stocks can lead to an inability to harvest abundant stocks. There are consequently trade-offs between the yield obtained during rebuilding and the rate of rebuilding. We retrospectively evaluate rebuilding plans in the US West Coast groundfish fishery to identify alternative harvest strategies that could have minimized adverse impacts to stakeholders while still achieving stock rebuilding targets. We use current assessments of 13 groundfish stocks to project spawning biomass and catch under various harvest policies. We estimate that an additional $886 million USD in ex-vessel revenue could have been obtained had an FMSY strategy permitting slower rebuilding rates been adopted. We also examined what catch limits would have been under a FMSY strategy using the information available at the time rebuilding plans were implemented. These alternative catch limits would have provided much greater fishing opportunity while still rebuilding the stocks. Our findings support those of the National Research Council, which in 2014 reported that rebuilding plans based on fishing mortality rates may be preferable to those focused on meeting strict rebuilding timelines.