INHIBITION OF DENITRIFICATION BY HYDROCAR BONS IN MARINE-SEDIMENTS - ROLE OF NEREIS-DIVERSICOLOR

An in vitro experiment has been carried out in order to illustrate the influence of the burrowing polychaete Nereis diversicolor an denitrif ication in hydrocarbon-loaded sediments. After 15 and 45 days, the den itrification activity in the different contaminated or non-contaminate d control (without macrofauna) and experimental (colonized by polychae tes) sediments was compared. In control contaminated sediments, the in hibition of denitrification is solely located in the surface layer (0- 2 cm). In the presence of polychaetes, the hydrocarbon buried in the b urrows extends the inhibition of denitrification in the sediment. As a function of the quantity of buried hydrocarbon, the inhibition of den itrification is observed up to a depth of 6 and 10 cm, after 15 and 45 days, respectively.