Benthic foraminifera are used as potential bio-indicators of pollution due to the “Erika” oil spill. The foraminiferal assemblages from a site situated on the tidal mudflat of the southern Bay of Bourgneuf (Vendée, France) have been sampled 19 times on a monthly/bimonthly scale. The field study reveals uncommon low densities and poor faunas in the first 21 months of the survey. In order to understand the effect of the “Erika” fuel, foraminiferal cultures with 0 to 72.0 mg per 100 ml of “Erika” oil were maintained in controlled conditions in the laboratory. In the laboratory, an experiment with 5.5 mg per 100 ml of oil shows morphological abnormalities, cellular modifications and a low rate of reproduction. These first results confirm the potential toxicity of the fuel No. 2 from “Erika” and the sensitivity of foraminifera to this pollutant.
