New Information on the Longevity of Pacific Ocean Perch (Sebastes alutus)

Abstract

A comparison of ages determined from surfaces of otoliths and from sections of otoliths showed that ages were similar up to a section age of 22–24 yr. The growth pattern observed on thin sections of otoliths and from broken and burned otoliths from the region of the nucleus was interpreted to indicate that Pacific ocean perch probably live much longer than previously thought. Because the criteria used to identify annuli from otoliths sections appeared valid for younger fish, there was no justification to reject the application of these criteria for estimating ages of older fish and thus no reason to reject the possibility that Pacific ocean perch might live to be older than 70 yr. Ages determined from sections of otoliths from other rockfish species found off the west coast of Canada such as Sebastes fiavidus and Sebastes brevispinis have ranged from 30 to 60 yr indicating that many species of rockfish may live longer than previously thought. Key words: age determination, otolith, maximum age, age determination errors, Pacific ocean perch, otolith sections