OTOLITH READING AS A TOOL FOR STOCK IDENTIFICATION

A method is presented for using otolith readings to identify stocks, a nd a refined statistical analysis of age/length keys is proposed based on 95% probability ellipses of log-log plots. Three case studies are given: (1) an application for the identification of the red-mullet sto ck in the central Mediterranean; (2) an approach for the identificatio n of stock units of anchovies in the Adriatic Sea; (3) an ''ab contrar io'' proof of the validity of the approach on hake in the central Medi terranean. The final discussion deals mainly with the justification of methods used. Evidence of independent circulation of water masses as gathered from oceanographic mesoscale studies seems to parallel prelim inary evidence of unit fish stocks from statistical treatment of age-l ength relations.