Effects of benthic mucilagenous aggregates on the hermatypic Mediterranean coral Cladocora caespitosa

In the temperate Mediterranean Sea, Cladocora caespitosa is the unique species of zooxanthelate reef-building coral and it threatened by different kinds of human pressure. The present study aims at evaluating the effects of a benthic mucilagenous aggregates bloom on a bed of Cladocora caespitosa. Colony density, cover and necrosis of the bed before and after the benthic mucilagenous aggregates bloom were compared. After the event there was an increase in necrosis which caused a decrease in colony density and cover. The study quantified the damage as an increase of necrosis of about 55% and an overall loss of percentage cover of about 85% of living C. caespitosa, suggesting that benthic mucilagenous aggregates may be a serious threat for this endemic Mediterranean hermatypic coral.