Marine ecosystems in the Mediterranean Sea are fundamentally driven by their pelagic compartments. Moreover, some pelagic species such as anchovy, sardine and tuna species, are highly commercial species. However, the knowledge gathered from them is frequently scarce, impairing our capabilities to correctly manage its marine resources. We investigated the seasonal and ontogenetic changes in the trophic structure of the pelagic ecosystem of the NW Mediterranean Sea. Trophic ecology was analysed by determining the stable isotopes of carbon and nitrogen in both juvenile and adult individuals of twelve species of fish and cephalopods collected throughout the year. Community-­¿isotopic descriptors revealed a consistency in the structure and the high importance of small pelagic as main trophic resources for pelagic and demersal predators. Overall, there were ontogenetic shifts in the trophic position of the species affecting the trophic relationships. We also found differences in the trophic niche and position between ecological similar species such some squids and medium pelagic fish. These results provided new insights in the trophic dynamics of the pelagic food webs, highlighting the importance of considering the ontogeny of species in trophic analysis and confirming the strong pelagic-­¿demersal coupling of Mediterranean marine ecosystems. This knowledge is essential to move towards and ecosystem-­based management of fisheries in the region

Integrated Marine Biogeochemistry and Ecosystem Research Open Science Conference (IMBER OSC 2014), Future Oceans, Research for marine sustainability: multiple stressors, drivers, challenges and solutions, 23-27 June 2014, Bergen, Norway

Peer Reviewed