Assessment of the Environmental Quality of French Continental Mediterranean Lagoons with Oyster Embryo Bioassay

Abstract

Abstract:In order to better understand environmental disturbances in the French coastal Mediterranean lagoons, we used an ecotoxicological approach based on the measurement of the toxicity of the sediments using oyster embryo bioassay that provides a basis for assessing the effects on the fauna of contaminants adsorbed on the sedimentary particles. The study covers all of the main lagoons of the French Mediterranean coasts of Languedoc Roussillon, Camargue, and Provence (Berre and Bolmon lagoons), where 188 stations were sampled. The toxicity tests provide evidence of variable levels of toxicity in sediments. Contaminated lagoons such as La peyrade, Le canet, and Ingrill and locally affected lagoons such as Bages-Sigean, Vaccares, Bolmon, and Berre have sampling stations with 100% of larval abnormalities during 24-h development. In all of the lagoons, the toxicity was mainly located close to local harbors and rivers. Salses Leucate (Languedoc roussillon) lagoon was found very clean, with no important toxicity. The results are discussed in terms of environmental disturbances of the coastal lagoons and with regard to the long-term monitoring of the impact of contaminants on the coastal environment.

Cultured heart cells from oyster : an experimental approach for evaluation of the toxicity of the marine pollutant tributyltin

“…Other in vitro models from marine invertebrates have also been used in marine ecotoxicological studies: oyster embryos (Galgani et al 2009;Mamindy-Pajany et al 2011), sponge primmorphs (Châtel et al 2011) and isolated invertebrate haemocytes (Anderson et al 1997;Cima et al 2004Cima et al , 2008Gopalakrishnan et al 2011;Greco et al 2011). In haemocytes, the study of pollutant effects demonstrated an alteration of parameters such as cell viability, phagocytotic activity, esterase activity or production of reactive oxygen species (Cima et al 2004;Gagnaire et al 2006;Gopalakrishnan et al 2011).…”

Accumulation of trace metals in sediments in a Mediterranean Lagoon: Usefulness of metal sediment fractionation and elutriate toxicity assessment

“…Toxicity includes both free-metals and inorganic complexes as labile fractions (Galgani et al, 2009;Fig. 5.…”

“…The biotest analysis procedure was performed as described in His et al (1999) which has been shown (Galgani et al, 2009) to be sensitive and suitable for understanding environmental disturbances affecting lagoon biota. Experiments using biotest analysis were carried out under nitrogen flux (using Glove Bag) to prevent any AVS oxidation when samples were submitted to elutriate preparation.…”

“…Experiments using biotest analysis were carried out under nitrogen flux (using Glove Bag) to prevent any AVS oxidation when samples were submitted to elutriate preparation. Elutriate extraction was done using an offshore deep sea water from Bastia (Corsica, France) as the reference water (Galgani et al, 2009). It was filtered through a 0.22 mm membrane just before biotest analysis.…”

“…With this bioavailable fraction we might improve our interpretation of the known toxicity demonstrated when larvae were directly exposed to elutriates (Geffard et al, 2002). For instance, thin toxicity tests have been used to study contamination in larval growth of the oyster Crassostrea gigas in coastal regions, the most sensitive environment to pollution (Geffard et al, 2002;Galgani et al, 2009;Mamindy-Pajany et al, 2010), yet they had never been tried in North African lagoons and certainly not in Bizerte Lagoon. Since, according to our hypothesis, (1) acid-volatile sulfides (AVS) are an important carrier phase for trace elements in marine sediments (Di Toro et al, 1990), and (2) trace elements are usually associated with fine-grained sediments because of their high surface-to-volume ratios and adsorption capability (Burdige, 2006;Szava-Kovats, 2008;Belabed et al, 2013), we should obtain enhanced information of the existing trace-element pollution potential by paying more attention to AVS and grain-size sediments.…”