Ariadna Mechó

First report of live deep-water cnidarian assemblages from the Malta Escarpment

Abstract A recent geo-marine survey of the Malta Escarpment revealed for the first time the existence of live cnidarian assemblages at about 300 m depth. These associations have been observed by means of a remotely operated vehicle (ROV) during surveys carried out on the upper part of the Malta Escarpment. The assemblages established on hard bedrock were chiefly composed of the antipatharian Leiopathes glaberrima. The Malta Escarpment is known to have been successfully colonised by deep-water scleractinian assemblages until the last glacial age. However, no living specimens had been observed, and only specimens of dead but relatively fresh Dendrophyllia cornigera had been reported. This area of the Mediterranean Sea, which connects the deep Ionian basin to the western Mediterranean, is largely unknown and in clear need of thorough exploration.

Visual faunistic exploration of geomorphological human-impacted deep-sea areas of the north-western Mediterranean Sea

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.