Effects of a trawling ban on the growth of young-of-the-year European hake, Merluccius merluccius in a Mediterranean fishing exclusion zone

Abstract

This study evaluates the effects of a trawling ban on the growth of young-of-the-year (YOY) European hake, Merluccius merluccius (L., 1758) by comparing size structure, length–weight​ relationship, condition and growth in three gulfs along the coast of northern Sicily (central Mediterranean Sea), one of which has been subject to a trawl ban for 15 years. Hake ranging between 60 and 330 mm were collected from 50 to 200 m depth in May 2005. The length frequency distribution of YOY fish showed a higher modal length in the untrawled gulf and comparable densities in the three gulfs, while larger fish were more abundant in the untrawled gulf. Length–weight relationships and condition factors did not highlight any trend linked to the effects of fishing and suggested a large variability of the system. Growth curves had comparable slopes while different intercepts in both length–weight and growth curves suggest that the observed larger modal size of the first cohort in the untrawled gulf could be linked to better condition and growth during the initial life stage in the pelagic environment.