Habitat related differences in lipid reserves of some exploited fish species in the north-western Mediterranean continental shelf

At a large-scale, the lipid content in the muscle of Pagellus acarne and Pagellus erythrinus was higher in the Gulf of Lions than in the Catalan Sea. Furthermore, there was a significant effect of depth on lipid content of Mullus barbatus, Mullus surmuletus and P. acarne, fishes with the highest lipid levels inhabiting the shallowest parts of the Gulf of Lions (all three species) and the Catalan Sea (last two species). At a small-scale, the study revealed differences in the condition of Diplodus sargus sargus between protected (Natural Park of Cap de Creus) and the unprotected habitats. Total lipid content in the muscle of D. s. sargus during spawning was higher within the protected area than in adjacent unprotected rocky areas. Because lipids play a critical role in the health, growth and reproduction of fishes, results from this study support the relative importance of some habitats (shallow v. deeper parts of the continental shelf, the Gulf of Lions v. the Catalan Sea, and the protected bottom areas of the Natural Park of Cap de Creus v. the unprotected bottom areas) for the productivity of different Mediterranean fishes.