Chronic Ecotoxicity of Mixtures of Cu, Zn, and Cd to the Zebra Mussel Dreissena polymorpha

• Published in: Ecotoxicology and environmental safety 1993-06, Vol.25 (3), p.315-327
• Main Authors: Kraak, M.H.S., Schoon, H., Peeters, W.H.M., Vanstraalen, N.M.
• Format: Article
• Language: English
• Subjects: 560300 - Chemicals Metabolism & Toxicology; Animal, plant and microbial ecology; ANIMALS; Applied ecology; AQUATIC ECOSYSTEMS; AQUATIC ORGANISMS; Biological and medical sciences; Bivalvia - drug effects; CADMIUM; Cadmium - analysis; Cadmium - toxicity; CHRONIC EXPOSURE; COPPER; Copper - analysis; Copper - toxicity; Dreissena polymorpha; ECOSYSTEMS; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on protozoa and invertebrates; ELEMENTS; Freshwater; Fundamental and applied biological sciences. Psychology; INVERTEBRATES; METALS; MOLLUSCS; MORTALITY; MUSSELS; RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT; TOXICITY; TRANSITION ELEMENTS; Water Pollutants, Chemical - toxicity; ZINC; Zinc - analysis; Zinc - toxicity
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1006/eesa.1993.1029

Organisms in contaminated freshwater ecosystems are often exposed to a variety of toxicants for their entire lifetime. To evaluate the ecological consequences of these long-term contaminations, the effects of mixtures of heavy metals on the filtration rate and survival of the freshwater mussel Dreissena polymorpha were studied during chronic exposure. In laboratory experiments, mussels were exposed to equitoxic mixtures of Cu + Zn, Cu + Cd, Zn + Cd, and Cu + Zn + Cd in concentrations causing a 50% decrease in filtration rate in short-term (48 hr) experiments. The filtration rate was measured once a week, during a 9- to 10-week exposure period. For all metal combinations effects on mortality increased when exposure time was prolonged from 48 hr to 9-10 weeks. In contrast, the effects on filtration rate did not increase, indicating that the filtration rate was related to the metal mixture concentration in the water, but not related to the metal concentrations in the mussels. Consequently, the effects on mortality and filtration rate were not related. In short-term experiments Cu + Cd were more than concentration additive, whereas in chronic experiments Cu + Cd were strongly less than additive, indicating a loss of potential for additivity during prolonged exposure. In general, Cu, Zn, and Cd did not affect each others uptake. It was concluded that the chronic effects of mixtures could not be predicted from their short-term effects nor from the chronic effects of the metals tested individually.