Assessment of three small tuna stocks exploited by the algerian fleet using the CMSY Method.

Abstract

Estimating the stock status is one of the most fundamental parts of fisheries management intended to preserve the aquatic resources. In this, study the assessment of three stocks of small tunas (Atlantic bonito Sarda sarda, Little tunny Euthynnus alletteratus and Bullet tuna Auxis rochei) caught in the algerian basin (Geographical Sub-Areas 4) was assessed using CMSY method. This method is suitable for data limited stocks and used to estimate maximum sustainable yield (MSY) and related fisheries reference points (Bmsy, Fmsy) from catch and resilience. The results of CMSY model suggest that the stocks of the Atlantic bonito and the Little tunny are overfished (0.5≤B2020/Bmsy<0.8) but not subject to overfishing (F2020/Fmsy≤1). The stock of Bullet tuna was assessed as overfished (B2020/Bmsy=0.639) and subject to overfishing (F2020/Fmsy=1.56). Results obtained from this first study provide a diagnosic of the stock status of these species, that needs to be refined by applying other models.