Energetic balance and ecological efficiency of pelagic communities in the Black Sea

A comparative analysis of the flow of the matter and energy has been carried out at the different trophic levels of the Black Sea ecosystem basing on materials for 1979 and 1992-1994. A considerable (as much as thrice) increase in phytoplankton gross production and simultaneous reduction in efficiency of its usage at all the subsequent levels attract attention. Processes of detritus-formation have enlarged greatly. The percentage of non-used detritus in the pelagic zone increased from 5 to 12% for the last twenty years. The output of the pure fish production reduced from 2,34•1012 kJ to 0,42•1012 kJ