Occurrence and distribution of the coral Dendrophyllia ramea in Cyprus insular shelf: Environmental setting and anthropogenic impacts

Abstract

Occurrence and abundance of deep-water corals in the Levantine Mediterranean Sea is still largely unknown. This is the first attempt to quantitatively describe a Dendrophyllia ramea population discovered in June 2015 during the CYCLAMEN expedition on board the Research Vessel Aegaeo. This population is the deepest ever described until now in the Mediterranean and was found on the outer insular shelf off eastern Cyprus (Protaras, 35°02′N; 34°05′E). Video transects conducted by means of a remotely operated vehicle revealed a well-developed population of D. ramea located on a sandy seabed at 125–170 m depth. The highest density was 6 colonies m−2 and on average 1.6 ± 1.4 (SD) colonies m−2. The population consists of isolated or piled up branches of various sizes and large colonies, some ∼50 cm max width. The corals thrive on soft bottoms, representing a rather novel aspect of the research on D. ramea, since the species is still considered to be mostly associated with rocky substrates. The occurrence of the species in sedimentary grounds makes it especially vulnerable to bottom contact fishing gears as bottom trawling. Spatial distribution of the coral population, as well as a first attempt to characterize its habitat, are explored as an approach to describe the habitat's suitability and the vulnerability for the species in the area.