Age and growth of the Pacific grenadier (Coryphaenoides acrolepis) with age estimate validation using an improved radiometric ageing technique

Current and historic longevity estimates for the Pacific grenadier (Corypha enoides acrolepis) range from 6 to greater than 60 years. Age estimates in this study using growth increment counts in thin otolith sections indicate the Pacific grenadier is a long-lived fish. To validate this growth informa tion, age was determined using the radioactive disequilibria of Pb-210 and Ra-226 in otolith cores from adult Pacific grenadier. Radiometric ages clos ely agreed with age estimates from counting growth increments, which confir ms their annual periodicity. Radiometric results indicate the Pacific grena dier can live at least 55.8 years (-7.4, +10.1 years). Growth increment cou nts from large fish indicate longevity may approach 73 years. Because the P acific grenadier is long-lived and matures late in life, it may be vulnerab le to heavy fishing pressure. Therefore, conservation measures need to be t aken to sustain this rapidly developing fishery.