A trial calculation of natural mortality estimators for Pacific saury

The Small Scientific Committee on Pacific Saury (SSC PS) is now moving toward an application of age-structured models to the Pacific saury stock assessment. Natural mortality coefficient is one of the key parameters in the age-structured models. Several natural mortality estimators were calculated for Pacific saury on trial. The calculated estimators distributed relatively high range, between 1.71 and 2.75. We also discussed several issues that have to be considered before we incorporate these estimates into age-structured models.