Long term functional changes within the Oligochaeta communities within the Danube River Delta, Romania

摘要: Within the Danube River delta's lakes Oligochaeta communities comprise between 7.9% and 36.2% of total biomass benthic fauna. Their importance in energy flow at ecosystem level changed relation to fast trophic transition all shallow hypertrophic state. The parameters budget dominant populations potential production benthivorous fish species assessed during 1976-1994 interval support this conclusion. P/B ratio, K 1 2 coefficients for both 1976-1980 1991-1994 intervals revealed different functional patterns response Potamothrix hammoniensis (Michaelsen, 1901) Limnodrilus hoffmeisteri (Claparede, 1862) varying conditions. Changes structure, size constituent their age distribution, as well quantity quality food supply hypoxia sediment/water interface were main factors that affected role these carrier from huge pool represented by sedimented organic carbon species.