Copper toxicity to larval Mercenaria mercenaria (hard clam)

• Published in: Environmental toxicology and chemistry 2002-04, Vol.21 (4), p.760-766
• Main Authors: LaBreche, Timothy M. C., Dietrich, Andrea M., Gallagher, Daniel L., Shepherd, Natalie
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; Bivalvia; Copper; Copper - pharmacokinetics; Copper - toxicity; Dose-Response Relationship, Drug; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on protozoa and invertebrates; Environmental Exposure; Fundamental and applied biological sciences. Psychology; Isochrysis; Larva - growth & development; Larval clams; Mercenaria; Metamorphosis, Biological - drug effects; Solubility; Survival Analysis; Toxicity; Water Pollutants - pharmacokinetics; Water Pollutants - toxicity
• ISSN: 0730-7268; 1552-8618
• DOI: 10.1002/etc.5620210411

Preset larval Mercenaria mercenaria were exposed to nominal concentrations of 1 (control) to 495 μg Cu/L in artificial seawater and monitored for mortality, activity, development, and metamorphosis in sealed 30‐mm plastic petri plates containing 1.5 ml of artificial seawater or toxicant solution. The plastic petri plates sorbed only about 2.6 μg/L at any dose and allowed direct observation of larval clams under a light microscope for a period of two weeks; control survivorship was in excess of 60% at 400 h. The dose‐response curve for mortality for clams exposed to copper and fed Isochrysis galbana was characterized by survival similar to or better than controls at doses of 5 and 14 μg Cu/L, while doses of 7 and ≥29 μg Cu/L exhibited mortality greater than controls. Values of lowest concentration at which 50% of the organisms died (LC50) were 62.4, 21.2, and 11.7 μg Cu/L, and the lowest observed adverse effect concentration values of 57, 29, and 29 μg Cu/L were determined at 48, 96, and 192 h, respectively. In contrast, activity, as judged by swimming, exhibited a typical exponentially decreasing response at these same concentrations. Experiments on the uptake of dissolved copper by I. galbana confirmed literature reports that these algae concentrate copper. Ingesting copper‐containing algae was demonstrated to be a source of copper toxicity for larval clams.