Progress towards rebuilding

André E. Punt
UW School of Aquatic & Fishery Sciences
February 9, 2005

The Pacific Fishery Management Council adopted rebuilding plans for eight groundfish species in 2004 in the form of Amendments 16-2 and 16-3 to the groundfish FMP. Each of these eight stocks will be re-assessed during 2005 and, as a consequence, there will be an opportunity to determine whether or not they have responded to recovery efforts and are on track to rebuild as previously projected. It is to be expected that the results of the 2005 groundfish assessments with not conform exactly with the results expected based on the previous assessments. The question that arises then is whether the fishing mortality rate used to set harvest guidelines specified as part of the rebuilding plan should be changed, and if so how. A further consideration is that data now available may show that the original basis for the rebuilding plan is no longer valid (e.g. because the values assumed for natural mortality or stock recruitment steepness have changed markedly). Although guidelines exist regarding how rebuilding analyses are to be conducted, there no guidelines to determine whether (and to what extent) rebuilding plans are to be updated given new information. The objectives of this presentation are to outline: a) a set of possible “rebuilding revision rules” which could be used to measure progress towards rebuilding (and make appropriate adjustments to rebuilding plans as needed), and b) a framework which uses simulation to provide a quantitative means to compare alternative rebuilding revision rules in terms of their effectiveness at correctly (and adequately) making adjustments to rebuilding plans.

Posted in Fisheries Think Tank.

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