link to AFSC home page

link to AFSC home page link to NMFS home page link to NOAA home page

Resource Ecology & Fisheries Management (REFM) Division

AFSC Quarterly
Research Reports
July-Aug-Sept 2010
In Memoriam
ABL Reports
FMA Reports
HEPR Reports
NMML Reports
RACE Reports
REFM Reports
All Reports (.pdf)
Quarterly Index
Quarterly Home

Status of Stocks & Multispecies Assessment Program

Development of a Productivity-Susceptibility Analysis and its Application to Alaska Groundfish Stocks

Productivity-susceptibility analysis (PSA), which evaluates vulnerability to overfishing based upon a stock's biological productivity and susceptibility to the fishery, can be used to classify stocks within a fishery management plan (FMP), assist in the creation of stock complexes, and inform precautionary control rules.

In the United States, NMFS has developed a PSA to evaluate the vulnerability of data-poor stocks. Evaluation criteria of productivity attributes were developed to be consistent with published relationships between quantities such as maximum size and age, growth rate, and natural mortality. Additionally, the NMFS approach includes a data quality score that describes the strength of information used to determine vulnerability.

Productivity scores for stocks in Alaska FMPs varied widely, whereas susceptibility scores were less variable possibly because inclusion in an FMP in itself implies a conservation concern. No clear demarcation was observed between high and low vulnerability stocks.

Several non-target stocks had vulnerability scores equal to or greater than those of target stocks, and determining vulnerability of data-rich target stocks provided a useful means for evaluating the relative vulnerability of data-poor stocks. The vulnerability and data quality scores have provided valuable information regarding the management of Alaska groundfish.

By Paul Spencer

<<< previous

next >>>

            Home | FOIA | Privacy | | Accessibility      doc logo