Distribution and behaviour of deep-sea benthopelagic fauna observed using towed cameras in the Santa Maria di Leuca cold-water coral province

Using a towed camera system a total of 422 individuals belonging to 62 taxa, of which 33 identified at species level, were counted in the Santa Maria di Leuca (SML) coral province, updating the knowledge on the biodiversity of this area and on the depth records of several species. The presence of coral mounds mostly in the north-eastern sector of the SML coral province seems to influence the large scale distribution of the deep-sea benthopelagic fauna, playing a role of attraction-refuge with respect to the barren muddy bottoms where fishing occurs in northward areas. Indeed, 38% of the species identified are of commercial interest and all are accidentally captured by trawling and/or longline outside the SML coral area. The Multiple Correspondence Analysis identified three main species/taxa groups: one including species/taxa more strictly linked to the bottom, resting and/or moving on the seabed, often sheltering and feeding; another group mostly consisting of species/taxa quietly swimming in the water column and mostly observed on rugged bottoms; and a third group made up of species/taxa actively swimming and hovering near the seabed. The behavioural patterns mostly related to activity and position of the fauna seem to determine their small-scale distribution while the effects of different benthic macrohabitats appear to be less important. Even less the depth within the bathymetric range examined. The behavioral patterns reflect aspects of the species life strategies, revealing common features in phylogenetically and ecologically distant species. Typical pelagic species, such as squids, were mostly observed to swim in the water column near to the bottom. Small individuals of Lepidopus caudatus, searching for food in very deep sediment, revealed a completely different behaviour from that known in adults. Aristeus antennatus was mostly observed in sediment-dominated bottoms in different positions and activities. The teleost Helicolenus dactylopterus exhibited a clear behavioural pattern of resting on seabed in different macrohabitats. The golden shrimp Plesionika martia and the fish Pagellus bogaraveo were mostly observed quietly swimming and hovering respectively near seabed. These two species seem to be influenced by the presence of corals.