Stock assessment of red mullet, Mullus barbatus Linnaeus, 1758 by length-based and catch-based models in the Northeastern Mediterranean

Abstract

Normal 0 false false false EN-US X-NONE X-NONE Stock assessment for Mullus barbatus using one catch-based and three different length-based data limited models was performed based on the official catch statistics and commercial length-frequency data from northeastern Mediterranean. The catch-based CMSY model results showed that the catch amount did not exceed the maximum sustainable yield (MSY), and the fisheries reference points (B/BMSY and F/FMSY) indicated a healthy stock status in 2020. The length-based Bayesian (LBB) estimator indicated that the biomass ratio was above safe biological limits (B < 0.5 BMSY), but fishing mortality was slightly higher than natural mortality. Likewise, length-based spawning potential ratio (LBSPR) results showed that SL50 for red mullet was higher than its Lm50, while the estimated median spawning potential ratio (SPR) was above the limit of 20% set as the biological reference point. The length-based integrated mixed effect (LIME) results were more optimistic than those from the LBB and LBSPR. The estimated SPR was found above 40% which is the target reference point for a sustainable stock. According to the results of different assessment models, the red mullet stock was deemed sustainable in terms of biomass, but monitoring of fishing pressure is recommended.