Distribution of enteric bacteria in Antarctic seawater surrounding the Dumont d'Urville permanent station (Adelie land)

The survival of human enteric bacteria in the aquatic environment has attra cted much interest in view of its public health significance. Untreated sew age has been released from Dumont d'Urville station, Antarctica, into the S outhern Ocean for several years. The spatial distribution of faecal bacteri a indicators was investigated in summer ice-free seawater near the French B ase station of the Adelie land area. A complementary seasonal survey of the occurrence of faecal coliform bacteria was conducted in seawater under the winter sea ice in a specific station. Relatively high bacterial densities (maximum 10(3) CFU 100 ml(-1)) were found in seawater surrounding the sewag e outfall, However, the contamination decreased rapidly with increasing dis tance from the outfall, In all samples collected further than 2 km, the bac terial indicators were absent or present in very small numbers. Faecal coli forms were not detected in samples collected at pristine sites. Despite the se relatively low contamination levels, faecal bacteria were always detecte d in the vicinity of the sewage outfall during the seasonal survey conducte d in ice and under-ice seawater. (C) 2000 Elsevier Science Ltd. All rights reserved.