ANALYSIS OF TRAWL SELECTIVITY STUDIES (ADDENDUM) - IMPLEMENTATION IN SAS

The SAS code herein is presented as an addendum to Millar and Walsh (1 992, Fish. Res., 13: 205-220) in which a version of the SELECT (Share Each LEngth's Catch Total) model was developed for analysis of selecti vity data from trouser trawl or alternate haul studies. To be more use ful to selectivity researchers, the logistic selection curve is parame trized here in terms of l50 (length of 50% retention) and SR (selectio n range, 175-125), rather than by the usual mathematical parameters of the logistic curve.