In-situ microcosms, a tool for assessment of pesticide impacts on oyster spat (Crassostrea gigas)
|Author(s)||Stachowski Haberkorn S1, Quiniou Francoise2, Nedelec M, Robert Rene3, Limon G4, de La Broise D1|
|Affiliation(s)||1 : Univ Bretagne Occidentale, F-29334 Quimper, France.
2 : IFREMER, Ctr Brest, Dept Biogeochim & Ecotoxicol, F-29280 Plouzane, France.
3 : IFREMER, Lab Phys Invertebras Marins, F-29840 Landunvez, France.
4 : Technopole Brest Iroise, Lab Idhesa, F-29280 Plouzane, France.
|Source||Ecotoxicology (0963-9292) (Springer), 2008-05 , Vol. 17 , N. 4 , P. 235-245|
|WOS© Times Cited||10|
|Keyword(s)||Epoxiconazole, Bentazon, Pesticide, Toxicity, Oyster, Microcosm|
|Abstract||Effects of the herbicide Basamais (bentazon) and the fungicide Opus (epoxiconazole) on oyster spat (Crassostrea gigas) were assessed using in-situ microcosms in a field experiment lasting 13 days. Six-week-old hatchery spat (mean size 1.1 mm), previously collected on PVC plates, was immersed in glass bottles filled with 200 mu m filtered seawater. Bottles were maintained underwater at 6 m depth and their water content changed every other day. Growth, measured as shell area index increase, was 126 +/- 4% in the control bottles. While no growth differences were observed between control and individual pesticide treatments at 10 mu g l(-1), oysters treated with a mix of 10 mu g l(-1) Opus and 10 mu g l(-1) Basamais showed a 50% growth reduction compared with the control (P < 0.0001), suggesting a synergistic effect of these contaminants. Laboratory controls in microcosms maintained in a water bath with filtered natural light, were not significantly different from in-situ microcosm controls in the field, for organic weight content or growth. This in-situ experiment in microcosms allowed us to conclude that: (1) oyster spat can achieve significant growth in bottles immersed in situ without supplementary food; (2) this microcosm system is reliable and easy to use for environmental toxicity tests with C. gigas spat; (3) such microcosm systems can also be run in a laboratory water bath instead of more technically difficult immersed field experiments; (4) the synergistic effect observed here, at a concentration simulating a peak agricultural runoff event, suggests that the impacts of pesticides could be a real threat for oysters in estuarine areas.|