Survival, growth and regeneration in explants of four temperate gorgonian species in the Mediterranean Sea

During the last few decades, Mediterranean epibenthic assemblages have been involved in mass mortality events, in which sea fans were one of the most threatened groups. Explants of the most common Mediterranean gorgonians (Paramuricea clavata, Eunicella cavolinii, E. singularis, and E. verrucosa, 40 explants from each species) were transplanted in the field in order to evaluate the response to transplantation, survival and growth rate of the cuttings during an annual cycle, from February 2003 to March 2004. Colonies of each species overcame transplantation stress and during the first three months they showed a mean survival rate of 98% and an average positive growth rate of 7.65%. In the summer season 2003, during the heatwave that affected the Mediterranean basin, the experimental cuttings suffered, showing a mean negative growth rate and a reduction of survival. At the end of the stress event, P. clavata revealed the worst recovery while all Eunicella species showed a good ability to recover. In particu...