Age-determination and age-length keys for Pacific saury, Cololabisa saira, from 2000 to 2018

The Small Scientific Committee on Pacific Saury (SSC PS) noted the need to share catch-at-age (CAA) data. In response to this need, we provided seasonal age-length key (ALK) information which had been posted on the NPFC Collaboration Site and could be utilized for estimation of CAA by each Member. In this document, we detailed our age determination method and described derivation method for ALKs for May to July and August to December from 2000 to 2018. Especially, a criterion to determine age 0 during fishing season was specified with taking into consideration a long spawning period of this species. We suggest our age determination method can be applied for all Members as a uniform method and then the Members should obtain their own ALKs from fish caught by their fisheries for future stock assessment.