LIKELY EFFECTS OF GLOBAL CLIMATE CHANGE ON THE BLACK SEA BENTHIC ECOSYSTEM

Occurrence and distribution of species in the Black sea are primarily determined by seawater temperature and salinity. The most recent predictions suggest that, by 2100, average air temperatures may be between 2 and 4 degrees C higher than at present and seawater temperatures may be as much as 2 degrees C higher than in 2000. The rise of the coastal zone seawater temperature may be higher than the open sea water average. It is expected that a warming of air and seawater temperatures will result in increased diversity of benthic marine life in the Black sea with adverse effects limited mainly to declines in abundance or loss of a small number of native species. Changes to a minority of biotopes might occur in the long-term. Depending on the temperature increase Mediterranisation of the Black sea fauna is in progress and occurs owing to immigration of new species. The aim of this article is discussing the global warming and the range of likely effects on marine benthic species. These effects may be related to changing water temperatures, changing water circulation or changing habitat. At present, to predict or detect the effects of climate change on marine benthic communities are quite difficult. But we can only provide educated guesses about potential changes and the consequences of those changes for the Black sea.