ATLAS OF MODERN DINOFLAGELLATE CYST DISTRIBUTION IN THE BLACK SEA CORRIDOR

We present here the first compilation of recent distribution of organic-walled dinoflagellate cysts from 159 surface samples collected in the Black Sea Corridor (BSC) which is a series of marine basins extending over 3,880 km from the Aegean to the Aral Sea (including Marmara, Black, Azov and Caspian Seas). Recent anthropogenic activities have deeply influenced marine ecosystems and biodiversity and by studying both modern and past distributions of this important plankton group, we can provide a baseline of land-sea linkages. About 60 taxa have been identified, and their taxonomy has been revised in accord with new morphological studies and/or genetic data. A number of species show distinct morphotypes that are being related to specific sea-surface conditions. Maps of distribution show the strong influence of sea-surface salinity, as well as temperature, to a lesser degree. The most common taxon, Lingulodinium machaerophorum, dominates most of the assemblages except in the Caspian Sea, where Impagidinium caspienense is the dominating species. Interestingly, species associated with marine conditions are well distributed in the Black Sea, such as Spiniferites mirabilis and S. ramosus. In contrast, Spiniferites cruciformis, which was first described from early Holocene sediments from the Black Sea, today occurs in low abundance in the northern part of the Black Sea, as well as in the Caspian and Aral Seas. A few taxa in the low salinity Black Sea, e.g. Achomosphaera andalousiensis, may be modern relicts of more widespread Mio-Pliocene distribution. In addition, based on late Quaternary records, we can estimate when species have entered these seas, either due to climatic conditions or anthropogenic activities.