EFFECTIVENESS OF BIOREMEDIATION FOR OIL-POLLUTED ANTARCTIC SEAWATER

The effectiveness of a specific fertiliser (INIPOL EAP 22) addition on bioremediation of oil-contaminated Antarctic coastal seawater was det ermined in the ''Terre Adelie'' area. Mesocosm studies were conducted to evaluate the effects of ''Arabian light'' crude oil contamination o n coastal bacterioplanktonic communities. After oil addition, regular surveys of the bacterial changes of the oil-contaminated seawater were performed during 5-week periods during the austral summer of 1992/199 3 and 1993/1994. All results (total, saprophytic and hydrocarbon-utili sing bacterial abundance) clearly revealed a significant response of A ntarctic bacterial communities to hydrocarbon contamination. A 1 order of magnitude increase of bacterial microflora occurred in seawater af ter crude oil contamination. A concomitant enrichment in oil-degrading bacteria was generally observed, from less than 0.001% of the communi ty in uncontaminated samples to up to 50% after 3 weeks of contaminati on. Addition of fertiliser (INIPOL EAP 22) induced clear enhancement o f both saprophytic and hydrocarbon-utilising microflora. Chemical anal ysis of the residual hydrocarbon fractions confirmed that fertiliser a pplication increased the rate of oil biodegradation.