PM07 Freshwater Bivalve Ecotoxicology
Exhibit Hall
8:00 AM - Monday, 10 November 2003
(PM140) Developing Standardized Guidance for Conducting Toxixcity Tests With Glochidia of Freshwater Mussels.
Wang, N1, Ingersoll, C1, Greer, I1, Whites, D1, Dwyer, J2, Roberts, A2, Augspurger, T3, Kane, C4, Tibbott, C5, 1 USGS, Columbia, MO, USA2 USFWS, Columbia, MO, USA3 USFWS, Raleigh, MO, USA4 USFWS, Gloucester, VA, USA5 USFWS, State College, PA, USA
ABSTRACT- Developing Standardized Guidance for Conducting Toxicity Tests With Glochidia of Freshwater Mussels. Wang N, Ingersoll CG, Greer IE, Whites DW, USGS, Columbia, MO, USA; Dwyer FJ, Roberts AD, USFWS, Columbia, MO; Augspurger T, USFWS, Raleigh, NC; Kane C, USFWS, Gloucester VA; Tibbott C, USFWS, State College, PA; Neves, RJ, USGS, Blacksburg, VA; Barnhart MC, Southwest Missouri State University, Springfield, MO. A joint research project between USGS, USFWS, and USEPA has been started to develop standardized guidance for conducting toxicity tests with glochidia of freshwater mussels. Multiple tests were conducted to assess the survival times of glochidia isolated from different species or different individuals of the same species. Copper, ammonia, or chlorine toxicity tests with glochidia also were conducted to examine the influences of exposure time, test chambers, and ages of glochidia. No differences were found in the survival times of glochidia held in static or flow-through conditions. Over 90% survival of glochidia was observed for >5 d with 6 of 11 tested species, while glochidia of the other 5 species survived less than 1 to 2 d. EC50s of the three chemicals decreased over the exposure periods of 6 to 96 h. Copper concentrations declined substantially in polystyrene plates but not in glass dishes after 48 h exposure period, whereas ammonia concentrations declined in both plates and dishes. Chlorine concentrations could be held constant in the diluter system with addition of water every 15 min. Similar EC50s were found when using 2 or 24-h old glochidia from a single female. These results indicate that the toxicity tests with glochidia of many freshwater mussels could be conducted for 24 or 48 h with a control survival of over 90% although shorter or longer tests might be appropriate for a particular species depending on the life history characteristics of the species and glochidia survival time.
Key words: mussel, unionids, glochidia, endangered species