Life in the Black Sea

Abstract

The Black Sea is considered to be a huge laboratory naturally hosting oxic, hypoxic and anoxic water masses permanently existing due to strong vertical stratification. While strong vertical stratification supports isopycnal distribution of various biogeochemical species, the wide range of redox conditions supports specific processes rendering the Black Sea a unique place to study the Earth System responses to climate changes and anthropogenic forcing. Since a large part of the basin (i.e. approx. deeper than 100 m) is anoxic, life forms in the Black Sea display limited diversity and almost all pelagic and benthic fauna and flora dwell in the shallower upper oxic water layers. The plants are represented by over 304 species of macrophyte seaweeds, most of them red seaweeds, to which are added the brown and green seaweeds. The phanerograms are represented by 5 species only. The animals are represented by the majority of invertebrates groups, with a total of 1750 species, and the vertebrates include fishes, birds and marine mammals, with total of 164 species. The mammals are represented by two species of dolphins, the seal and the harbor porpoise: common dolphin (Delphinus delphis ssp. ponticus), common bottlenose dolphin (Tursiops truncatus ssp. ponticus), monk seal (Monachus monachus) and harbor porpoise (Phocoena phocoena ssp. relicta).