Overview The implementation of new National Standard guidelines published by NOAA Fisheries in 2009 requires the classification of fish stocks in a fishery management plan (FMP). Target stocks, as well as non-target stocks that are caught incidentally in large numbers, are considered to be “in the fishery”. Annual catch limits (ACLs) are required for these stocks. Fishery management councils have the option of designating a second category of less-impacted stocks, “Ecosystem Components” (EC), for which ACLs are not required. However, these stocks are monitored and councils may adopt management measures designed to limit incidental catches of EC stocks. To aid in the classification of stocks, as well as to provide advice on the formation of stock complexes and other management actions, NOAA Fisheries convened a Vulnerability Evaluation Working Group (VEWG) in 2008. This group was tasked with developing an analytical tool for assessing the vulnerability of stocks in an FMP (the word “vulnerability” appears frequently in the National Standard guidelines). The work of the VEWG is complete and will be published soon as a NOAA Technical Memorandum and in a peer-reviewed journal. A preliminary report and other supporting materials that explain the group’s work in detail can be found at www.nmfs.noaa.gov/msa2007/vulnerability.htm. Here, a brief review of the analysis is provided to aid interpretation of the results for Alaska groundfish. The analysis developed by the VEWG is based on previous work in Australia and elsewhere. It compares two main features of a fish stock that together influence its vulnerability to fishing: productivity, which determines a population’s natural capacity for growth and its resilience to fishery impacts; and susceptibility, which indicates how severe those fishery impacts are likely to be for the population. Productivity and susceptibility are evaluated by scoring a number of related attributes. For productivity, these are mainly life-history traits such as natural mortality rate and age at maturity; susceptibility attributes include spatial overlap between the stock and the fishery, stock status, etc. The table below lists all attributes evaluated in the productivity-susceptibility analysis (PSA):
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