Critical review of selectivity studies for Mullus barbatus (Red mullet) and Merluccius merluccius (European hake) in Mediterranean trawl fisheries

Given the importance of hake (Merluccius merluccius) and red mullet (Mullus barbatus) in the Mediterranean bottom trawl fisheries, the relationship between mesh size, L50, SR and SF was reviewed in this paper with the contributions of several scientists, with the main objective to estimate reference selection for different codend mesh size. Considering that the real processes are more complex, several Mediterranean fisheries scientists started to explore effects of other parameters (e.g. mesh size, mesh configuration, twine diameter, mounting ratio, etc.) on codend selectivity. This study presents an updated literature review of the Mediterranean bottom trawl selectivity, discusses and summarises the data and the work presented in several papers/reports. Advises on the experimental methodology and data analysis are provided for a better estimation of selection parameters. The review of the literature was undertaken during 2006 and further technical information on the gear characteristics were subsequently obtained contacting by correspondence the authors. The scarcity of review papers demonstrated the need for this review. In particular, between 1969 and 2007, only 20 and 28 relevant papers were found respectively for red mullet and hake, while only few for other demersal species. Updating of published literature is on going for these 2 species and needs to be extended to other main commercial species.