Age & Growth Program

Oldest and Biggest Rockfish?

An otolith from the shortraker rockfish described in this article that was aged 90 to 115 years.

On 22 March, Mike Myers from the catcher-processor Kodiak Enterprise, brought an unusually large shortraker rockfish, Sebastes borealis, caught just south of the Pribilof Islands in the Bering Sea in to the AFSC’s wet lab (see FMA Division Report). The fish was big, measuring 112 cm in fork length and weighing 27.6 kg. Was this the largest and oldest rockfish we have ever seen? For just about everyone in the lab this was probably true. Survey databases indicated no heavier rockfish was ever recorded and only one longer shortraker at 113 cm. However, observer databases indicated records of one shortraker rockfish at 119 cm and one shortraker weighing 30.6 kg.

But was this specimen the oldest? Shortraker rockfish are extremely difficult to age, but recently the Age and Growth Program developed new otolith ageing criteria for this species. The age agreed upon was 90 years old, with a possible age range of between 90 and 115 years. Is this the oldest rockfish specimen we have ever aged? Notable old specimens of rockfish include one other shortraker rockfish aged 116 years old, one specimen of rougheye rockfish, Sebastes aleutianus, aged 129 years old, and one specimen of Pacific ocean perch, Sebastes alutus, aged 100 years old.

So this rockfish was neither the longest, heaviest, or oldest rockfish in our databases, but it was very close on all counts. It will probably be the heaviest and oldest rockfish seen by anyone lucky enough to have seen it that day in March. Thank you, Mr. Myers, for bringing us this very interesting specimen.

By Dan Kimura and Charles Hutchinson