Stock Assessment of Shortfin Mako Shark in the North Pacific Ocean Through 2016

This is the Report of the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean (ISC) Shark Working Group, published in July 2018 at the ISC meeting in Yeosu, Korea.

This document presents the results of the ISC SHARKWG’s first full stock assessment of shortfin mako shark (SFM, Isurus oxyrinchus) in the North Pacific Ocean (NPO) conducted in 2018. Due to a lack of biological and fisheries information, an indicator-based analysis was conducted in 2015. For the present analysis, time-series of catch, relative abundance, and sex-specific length composition from multiple fisheries were developed for the modeling period (1975 – 2016). In addition, new biological information, and research into parameterization of the Beverton-Holt stock recruitment relationship enabled the development of a size-based, age-structured model using the Stock Synthesis modeling platform.