Preliminary assessment of Cladocora caespitosa population at Tremiti Islands Marine Protected Area (Southern Adriatic Sea)

The scleractinian Cladocora caespitosa is a Mediterranean-endemic bioconstructor of the infralittoral zone. This study reports the occurrence of C. caespitosa living in the lower layer of the infralittoral zone (from 15 to 21 m depth), on detritic bottom consisting of gravels and rhodoliths, at Tremiti Islands Marine Protected Area (Southern Adriatic Sea). The density and coverage measured are one of the highest reported thus far. Our results are particularly relevant because most of the studies reported the scarce presence of this species on lower-infralittoral soft substrates. Three photo-transects were carried out at 15, 18 and 21 m depth, and preliminary differences found between the three transects can be explained by the depth gradient, with probable high influence of waves and currents. Colonies were in good conservation status, being mostly healthy and not affected by bleaching or mechanical damage. Further studies will be focused on finding new populations of this coral at Tremiti archipelago, as well as on searching for the presence of any relation between distribution and bio-ecological traits with abiotic factors.