This study reports the composition and distribution of demersal megafauna from various north-western Mediterranean submarine areas such as canyons, seamounts and landslides between 60–800 m depth, based on remotely operated vehicle (ROV) observations. From a total of 30 h of video, 4534 faunistic observations were made and analysed in relationship to environmental factors (i.e. topography, substrate type and depth). In addition, anthropogenic impact was quantified by grouping observations in four categories: fishing nets, longlines, trawl marks and other litter. The different targeted environments showed similarities in faunal composition according to substrate, depth and topography. Our results also indicated the presence of anthropogenic impact in all the sampled areas in which litter and trawl marks were the most observed artefacts.

Larval stages of protozoeas II and III and zoea I of Aristeus antennatus were found in low numbers near the red shrimp fishing grounds off the Balearic Islands. The discovery of the larvae in the upper water layers has led to a proposed model of reproductive dynamics, in which newly hatched larvae perform an ontogenetic migration up through the water column to surface waters, where the larval stages develop. Data on the horizontal distribution of larvae presented, can contribute to an understanding of the dynamics processes of larval dispersal of the zoeal stages.