An alternative hypothesis for the reconstruction of time series of catches for North And South Atlantic stocks of shortfin mako shark

The reconstruction of shark catch time series is particularly important for stock assessments, as the nominal catch data on sharks is usually very limited and a major source of uncertainty. This document provides an alternative hypothesis for the reconstruction of shark catches in the Atlantic (ICCAT fisheries) based on a method developed for the EUPOA-Sharks (EU Plan of Action for Sharks). The estimation method is based on ratios of sharks:main species catches, obtained from observer programs, literature revision and/or personnel communications. In this paper we present the average estimations by fleet/métier for the Atlantic (2000-2015) as well as time series for 1971-2015. A specific estimation for shortfin mako by stock is also presented. In this specific case, the main differences in the declared vs. estimated catches are more relevant in the earlier years of the series, which is consistent with more underreporting and lack of species specific information in the earlier years. These time series (North and South stocks) can be considered for use as alternative catch histories in the 2017 ICCAT SMA stock assessment.