Coastal benthic diversity in the Black and Aegean Seas
Quantitative data pertaining to the composition of macrobenthic communities of soft bottoms along the coastal zones of the Black and Aegean Seas are reviewed. The study area includes one site in the Russian coastal zone, four sites in Ukraine (at depths 3-125 m), four sites in Bulgaria (at depths 12-83 m), and four sites in Greece (at depths 9-90 m). The species variety, population density and community diversity are compared between Seas, among regions and among stations. The fluctuation of these parameters in connection to anthropogenic impact (ranging from open undisturbed sites to those receiving heavy organic and chemical effluent) are discussed. The low species number of benthic fauna in the Black Sea, as opposed to the richness of the Aegean Sea (three times higher) a ratio well established for other marine groups, is not reflected in the overall abundance. Thus, the average population density of benthic organisms may reach 12352 ind per m2 in the Black Sea (Cocketrice sandy bank) while in the Aegean it did not exceed 4,000 ind per m2 (Saronikos Gulf). Community diversity was always lower in the Black Sea than similar sites in the Aegean Sea. Within the various regions examined, the protected areas exhibited the most complex community structure.