PARENT SESSION
PM6 - Fate & Effects of Metals: Regulation and Risk
Monday, 18 November 2002
8:00 AM to 6:30 PM
Exhibit Hall

(P268) Prediction of Acute Toxicity of Copper to Mytilus edulis Using the Biotic Ligand Model.

Arnold, W^*,1, Santore, R², Lee, C³, ¹ Copper Development Association Inc., New York, NY² HydroQual, Inc., Camillus, NY³ International Copper Association, New York, NY

ABSTRACT- The Biotic Ligand Model (BLM) was recently developed and has proved efficient in predicting the acute toxicity of a variety of metals to freshwater organisms. Its utility and strength have resulted in its proposed incorporation into the regulatory framework for calculating water quality criteria for copper in freshwater. In 2000 and 2001, studies were conducted on estuarine and marine water samples to test the utility of the BLM for predicting toxicity to the marine bivalve Mytilus edulis, the most sensitive organism and test in the US EPA's saltwater criteria database. These studies were performed in cooperative effort with regional regulatory authorities, dischargers, and non-government organizations performing water effect ratio tests throughout the North and Central San Francisco Bay. The BLM was calibrated to copper toxicity to M. edulis data developed for an earlier WER study for the South Bay. The application of the model to the North and Central Bay was conducted "blind" without prior knowledge of the toxicity test results. The results of this effort indicate that there is a strong predictive relationship between copper toxicity and dissolved organic carbon concentrations of the samples. The BLM demonstrated acceptable predictive capabilities for samples containing dissolved organic carbon between 0.5-10 mg DOC/L. Furthermore, costs to perform the BLM analysis were approximately one quarter that of performing water effect ratio tests.

Key words: copper, toxicity, modeling, BLM