title: The influence of organic chelators on the toxicity of copper to embryos of the Pacific oyster, Crassostrea gigas.
abstract: The effects of copper on the development of Crassostrea gigas embryos were determined with a 48-hr static bioassay. In filtered, sterilized seawater from Bodega Bay, California, the LC100 was 20 microgram Cu/L, and the LC50 was 12 microgram Cu/L. Destruction of the naturally occurring dissolved organic material in the culture water by UV oxidation decreased embryo survival at 10 microgram Cu/L. The addition to seawater of five organic chelators (ethylenediaminetetraacetic acid (EDTA), sodium citrate, glycine, and oxalate at 1 x 10(-6) M, and humic matter at 2 mg/L) increased embryo survival. EDTA and humic matter were the most effective chelators; EDTA significantly increased survival at 100 microgram Cu/L and humic matter did so at 40 microgram Cu/L. The ability of a chelator to increase survival was related to the stability constant of the copper-chelator complex.
mesh_terms: D000818:Animals; D002614:Chelating Agents / Q000494:pharmacology*; D003300:Copper / Q000032:analysis / Q000633:toxicity*; D004347:Drug Interactions; D007928:Lethal Dose 50; D010125:Ostreidae / Q000196:embryology*; D014867:Water / Q000032:analysis; D014873:Water Pollutants / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D002614:Chelating Agents; D014873:Water Pollutants; D014874:Water Pollutants, Chemical; D014867:Water; D003300:Copper