 |
Cardona L, Martínez-Iñigo L, Mateo R, González-Solís J
The role of sardine as prey for pelagic predators in the western Mediterranean Sea assessed using stable isotopes and fatty acids
Sardine is the most abundant small pelagic fish in the western Mediterranean Sea. Cardona and colleagues used fatty acids and stable isotopes to asses the existence of a sardine based wasp-waist ecosystem. Results indicate that sardine is certainly the staple food of most of the seabirds studied, but the majority of the predatory fishes relied primarily on other small pelagic fishes, instead. The aggregation of sardines at cold, diatom rich areas, opposite to the scatter of anchovies over most of the continental shelf, may explain that pattern. Furthermore, discards from bottom trawlers increase the availability of sardine for seabirds. Accordingly, the ecosystem consists of two parallel food webs, one based on diatoms and sardines and the other on dinoflagellates, anchovies and horse mackerel.