Study of the connectivity of Palinurus elephas among different no-take areas of Sardinian sea (cw Mediterranean) integrating biological, genetic and mark-recapture data

The continuous market demand of spiny lobster Palinurus elephas and the consequent impoverishment of resources made indispensable the research of innovative managerial approaches. In this context, since 2009 we have carried out a restocking experiments in 19 central western Mediterranean areas that extends over surface ranging between 3 and 11 hectares, at depth of between 50 and 100 m. In these areas, from 2010 to 2011 about 1000 tagged lobsters were released. All these lobsters of TL<26 Stine Sofie (9 yrs)71cm were caught by fishermen in commercial neighboring areas. The biometric and sex parameters of all specimens were recorded. All of these data will allow to study the population dynamics, growth pattern and movements of the lobsters in the different areas and over the years. Furthermore, the connectivity of spiny lobsters, P. elephas, among and within the restocking areas have been also investigated using genetic markers. Microsatellite loci revealed significant differentiation among the three areas (Northern coast, Southern coast and central Western coast), in particular as concerns gene diversity and allelic richness, with the lowest genetic diversity recorded in the most exploited area. Furthermore, the comparison of samples of the “Su Pallosu reserve” collected in 1998 and in 2010 (12 year after its establishment) permitted to record an increased genetic diversity, supporting the effectiveness of no-take areas for preserving the genetic variability and hence the long term persistence of populations.