Françoise Quiniou

Arrest and Delay in Embryonic Development in Sea Urchin Populations of the Bay of Brest (Brittany, France): Link with Environmental Factors

Abstract The deficiencies observed in the larval development of several populations of the sea urchin Sphaerechinus granularis from the Bay of Brest were used to evaluate the quality of seawater. The comparison of ecotoxicological indices reveal that there are significant differences between the reference populations and the populations located in the centre and northern areas of the Bay, the sea urchins living at the mouth of the river Aulne having the highest level of blockage and delay in embryonic development. Analysis of heavy metals present within the sea urchin gonads reveals concentrations that are 2– 5 times higher than those observed in the other populations of the Bay. A discussion is carried out based on these results and on different environmental factors. The developmental abnormalities observed at this site could be linked to dumping of heavy metals from pyrotechnical waste but also to dumping of pesticides from agricultural sources, and TBT plus PAHs concentrations from urban and port activities.

Effect of Bentazon on Growth and Physiological Responses of Marine Diatom: Chaetoceros gracilis

The herbicide bentazon (CASRN 25057-89-0) is extensively used in agriculture in Brittany (France) to replace atrazine. Bentazon is not readily adsorbed by soil and therefore it enters adjacent freshwater ecosystems, making its way to estuarine and marine waters areas. Information regarding its effects on marine ecosystems is scarce. Phytotoxicity assessments were conducted in the laboratory on the common diatom Chaetoceros gracilis using both the active ingredient and its formulated product (Basamaïs). The 3 day EC50 using cell counts were, respectively, 150 mg/L and 60 μg/L for bentazon active ingredient and for bentazon-formulated while cellular volume was increased. Although bentazon is known as a photosystem II inhibitor, it produced an increase of pigment (chlorophylls a, c, and carotenoids) content, ATP synthesis, rates of photosynthesis and respiration, and TBARS formation. Therefore, pigments cannot be used as biomarkers of toxicity. Algal cell recovery from bentazon effects occurred after 6–9 days, suggesting a tolerance mechanism.

In vitro test-based comparison of pesticide-induced sensitivity in marine and freshwater phytoplankton.

This study aims to assess the effects of two pesticides, namely the insecticide carbofuran and the herbicide isoproturon, on monospecifically cultivated marine and freshwater phytoplankton according to standard methods. In the presence of pesticide, growth rates were lower in marine species Chaetoceros gracilis and Phaeodactylum tricornutum than in freshwater species Chlorella vulgaris and Selenastrum capricornutum after 72 hours. The EC50 values were obtained with the REGTOX Macro software, and the NEC values by applying the DEBtox model.

Ecotoxicity of ethylene glycol monomethyl ether and its acetate.

Ethylene glycol monomethyl ether (EGME) and ethylene glycol monomethyl ether acetate (EGMEA) have been tested for their acute and chronic toxicity to various organisms occupying different trophic levels in the aquatic ecosystems. The results obtained in this study and those collected from the literature clearly reveal that EGME does not present short- or long-term ecotoxic effects in the ranges of concentrations likely to be found in aquatic environments. Indeed, in general, concentrations of 1000 to 10,000 mg/L of EGME are necessary before significant adverse effects can be observed in aquatic species. Conversely, acute toxicity occurs in fish at about 50 mg/L of EGMEA, and reproduction of Ceriodaphnia dubia is affected by 0.06 mg/L of this chemical. A teratogenic effect—with a specific malformation of the eyes—occurs in Xenopus laevis in the presence of 75 mg/L of EGMEA. This study was partially supported by the French Ministry of the Environment as part of the PNETOX program (1998)