Foraminifera as potential bio-indicators of the “Erika” oil spill in the Bay of Bourgneuf: Field and experimental studies

Abstract

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. © EDP Sciences, IFREMER, IRD 2004.