Mediterranean coral population dynamics: a tale of 20 years of field studies

In contrast with the number of studies on tropical species, analyses of the variation of growth parameters with environmental variables in temperate areas are very scarce. The growth of only four species of scleractinians has been analyzed in natural Mediterranean populations: Cladocora caespitosa (Family: Faviidae), Balanophyllia europaea and Leptopsammia pruvoti (Family: Dendrophylliidae), and Caryophyllia inornata (Family: Caryophylliidae). Notwithstanding the importance of obtaining information on coral population dynamics, the first study on a Mediterranean scleractinian dates back less than 10 years. To date, field analyses of the relationships between environmental parameters and growth and population dynamics of Mediterranean scleractinians are available only for two solitary dendrophyliid species: B. europaea and L. pruvoti. Available literature on growth and population dynamics of natural scleractinian populations of the Mediterranean Sea is reviewed in the present work. As general trends, it seems that: (1) solitary species have a definite growth pattern, in contrast with colonial species; and (2) symbiotic species are more sensitive to increasing temperatures and more vulnerable to global warming. Knowledge on the growth and population dynamics of Mediterranean species has significantly increased in the last 20 years, and more effort is still required to gather the necessary information for protecting a hotspot of biodiversity like the Mediterranean Sea from the threats of global environmental change.