Estimating Sustainable Yields for Data-Poor Stocks

Alec MacCall (SWFSC Fisheries Ecology Division) completed beta testing for his Depletion-Corrected Average Catch (DCAC) method for estimating sustainable yields for data-poor stocks. The method has been posted for general use in the NMFS Fisheries Toolbox.

DCAC is based on the idea that the average catch has been sustainable if abundance has not changed, and makes a correction to that average if abundance has increased or decreased (which may be the subject of an educated guess based on subjective impressions). The magnitude of the correction depends on the approximate natural mortality rate, which should be about 0.2 or smaller to apply this model. Uncertainty is recognized in all of the parameters in the model, and is reflected in the output probability distribution.

(January 21, 2009)