Time-series analysis of abundance indices of deep sea resources in the Strait of Sicily

Abstract

Time-series of abundance indices of deep sea demersal resources (501-800m) derived by the MEDITS trawl survey in the Strait of Sicily (GSA 16) were analysed by aggregated taxa (bony fish, cartilaginous fish, cephalopods and crustaceans) and species using a polynomial approach. The results showed a significant increasing trend of the cartilaginous fish and cephalopods, in terms of biomass (kg/km) and density (n/Km) indices, whereas temporal pattern in bony fish and crustaceans resulted not significant. Helicolenus dactylopterus, Hoplostetus mediterraneus, Galeus melastomus, Nephrops norvegicus and Aristaeomorpha foliacea showed significant trends in both number and weight, whereas Aristeus antennatus, Etmopterus spinax and Chimera monstrosa only in biomass. ; This work was carried out within the Data Collection Regulation and Framework - module trawl surveys MEDITS funded by European Union and the Italian Ministry of Agricultural, Food and Forestry Policies. ; peer-reviewed