Publication Abstract

A simple model for estimating biological reference points from noisy stock-recruitment data

E.C.E. Potter and M.D. Nicholson

We describe a simple method for setting biological reference points from noisy stock-recruitment relationships. The model assumes that there is a critical stock level below which recruitment decreases linearly towards zero stock and recruitment, and above which the recruitment is constant. The position of the critical stock level is determined by searching for the value which minimises the residual sum of squares. This approach has been applied to the quasi-stock-recruitment relationships used to develop national conservation limits from the pre-fishery abundance analysis of salmon in the NASCO-NEAC area. It provides a more objective method for estimating these reference points than the non-parametric options presented previously. It also provides a measure of the uncertainty around these estimates. The model can be implemented within an Excel spreadsheet.

Reference:

E.C.E. Potter and M.D. Nicholson, 2001. A simple model for estimating biological reference points from noisy stock-recruitment data. ICES CM 2001/M:04. 11pp.