RP10 Aquatic Ecotoxicology
Thursday, 17 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(WAN-1117-663237) Acute and chronic toxicity of copper, ammonia, and chlorine to early life stages of freshwater mussels.

Wang, N¹, Ingersoll, C¹, Greer, I¹, Whites, D¹, Dwyer, F², Roberts, A², Augspurger, T³, Kane, C⁴, Neves, R⁵, Barnhart, M⁶, ¹ U.S. Geological Survey, Columbia, MO² U.S. Fish and Wildlife Service, Columbia, MO³ U.S. Fish and Wildlife Service, Raleigh, NC⁴ U.S. Fish and Wildlife Service, Gloucester, VA⁵ U.S. Geological Survey, Blacksburg, VA⁶ Southwest Missouri State University, Springfield, MO

ABSTRACT- Early life stages of freshwater mussels are reportedly more sensitive to many chemicals compared to common test organisms. However, concerns have been expressed regarding the lack of standardization of methods for conducting toxicity test with freshwater mussels. The objectives of this project were to (1) refine methods for conducting toxicity tests with early life stages of freshwater mussels and (2) evaluate acute and chronic toxicity of copper, ammonia, and chlorine to larval (glochidia) and juvenile mussels. During the past four years, over 120 acute and 2 chronic toxicity tests with copper, ammonia, or chlorine were conducted with 15 mussel species and 5 common test organisms. The results of 48-h tests with glochidia, 96-h toxicity tests with newly-released juveniles and 2-month-old juvenile mussels, and 28-d tests with 2-month-old juvenile mussels of all species tested demonstrated that early life stages of mussels were generally more sensitive to copper and ammonia than five common test species of fish, cladocerans, or amphipods. Based on 4-d acute and 28-d chronic tests with juvenile mussels, acute to chronic ratios were calculated as 2.7 for copper and 7.6 for ammonia. The median effect concentrations (EC50s) or chronic values of copper and ammonia for glochidia and juvenile mussels were typically at or below the acute or chronic USEPA water quality criteria (WQC), whereas EC50s of chlorine were generally above the acute WQC. Results indicate that the current acute and chronic WQC for copper and ammonia might not provide adequate protection to mussel species. The methods for conducting toxicity tests with freshwater mussels are currently being balloted through ASTM and toxicity data generated with mussels using these methods should be useful for developing WQC.

Key words: mussels, glochidia, juveniles, toxicity