Linking spatial distribution and feeding behavior of Atlantic horse mackerel (Trachurus trachurus) in the Strait of Sicily (Central Mediterranean Sea)

• Published in: Journal of sea research 2017-03, Vol.121, p.47-58
• Main Authors: Rumolo, Paola, Basilone, Gualtiero, Fanelli, Emanuela, Barra, Marco, Calabrò, Monica, Genovese, Simona, Gherardi, Serena, Ferreri, Rosalia, Mazzola, Salvatore, Bonanno, Angelo
• Format: Article
• Language: English
• Subjects: Area; Body length; Content analysis; Continental shelves; Duration; Ecological aggregations; Ecosystem analysis; Ecosystems; Environmental conditions; Environmental factors; Environmental variables; Feeding; Feeding behavior; Feeding habits; Fish; Fish stocking; Food availability; Food chains; Food supply; Food webs; Geographical distribution; Habits; Isotopes; Mackerel; Marine fishes; Ocean circulation; Ontogeny; Pelagic fish; Photosynthetically active radiation; Prey; Radiation; Salinity; Salinity effects; Spatial distribution; Stable isotopes; Stomach; Stomach content; Strait of Sicily; Temperature; Trachurus trachurus; Trophic web; Upwelling; Water column
• ISSN: 1385-1101; 1873-1414
• DOI: 10.1016/j.seares.2017.01.002

The Atlantic horse mackerel (Trachurus trachurus) is a semi-pelagic fish species with a wide geographical distribution and commonly found on the continental shelf. In recent years, the species has received some attention due to its ecological role in pelagic food webs. Stable isotope of nitrogen and carbon (δ15N and δ13C) and Stomach Content Analysis (SCA) of T. trachurus were adopted as tools to provide necessary knowledge on its feeding habits in the Strait of Sicily. The strong correlation found between δ15N and δ13C values with body length, together with significant ontogenetic shift evidenced by SCA, could be associated to changes in food availability, which in turn is triggered by environmental conditions. Spatial distribution of T. trachurus in the study area, mainly for small and medium size specimens, is linked to lower temperature, salinity and Photosynthetically Active Radiation (PARsat) values with higher aggregations on the Adventure Bank (i.e., an area characterized by periodic upwelling events). Larger size specimens mostly inhabited shallower waters characterized by higher temperature, salinity and PAR values, typical of the central-eastern part of the study area. Our results support the hypothesis that feeding behavior of T. trachurus is strictly linked to environmental factors (i.e. chiefly oceanographic conditions of the water column and day duration) that in turn influences the distribution of its prey. Findings can supply knowledge needed for improving fish stock management and promoting plans able to take into account also local ecosystem analysis. •Trophic ecology of T. trachurus was examined in the Strait of Sicily.•SCA and δ13C and δ15N analysis are tools to determine feeding habits of fish.•Spatial distribution of T. trachurus was linked to environmental factors.•Findings can supply knowledge needed for improving fish stock management.