Habitats of the Cap de Creus continental shelf and Cap de Creus Canyon, Northwestern Mediterranean

Abstract

The Cap de Creus continental shelf and Cap de Creus canyon are located in the southernmost sector of the Gulf of Lions, in the northwestern Mediterranean. The Cap de Creus continental shelf contains sandy and muddy sediments and an abrupt morphology, with rocky outcrops, relict bioherms, erosive features, and planar bedforms. The Cap de Creus canyon breaches the shelf at a depth of 110 m and denotes a marked difference in the morphology between the northern and the southern flank, reflecting a different depositional regime. The most common substrates correspond to coarse and medium sands (28%) and silty sediments (40%). The most common megabenthic assemblages of the shelf correspond to the communities of “offshore detritic” (31.95%) and “coastal terrigenous muds” (36.99%), mostly dominated by sea pens, alcyonaceans, and ceriantharians. The northern flank of the Cap de Creus canyon is predominantly depositional, whereas the southern flank is erosional. Rocky outcrops provide the substratum for cold-water coral (CWC) communities’ development, in which the white coral Madrepora oculata is the most abundant species