MP13 Aquatic Ecotoxicology
Monday, 14 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(ING-1117-740089) Development of an ASTM standard guide for conducting laboratory toxicity tests with freshwater mussels.

Ingersoll, C¹, Augspurger, T², Barnhart, C³, Cope, G⁴, Dwyer, F⁵, Bishop, C⁶, Neves, R⁷, Newton, T⁸, Roberts, A⁵, Wang, N¹, ¹ US Geological Survey, Columbia, MO, USA² US Fish and Wildlife Service, Raleigh, NC, USA³ Missouri State University, Springfield, MO, USA⁴ North Carolina State University, Raleigh, NC, USA⁵ US Fish and Wildlife Service, Columbia, MO, USA⁶ EA Engineering Science and Technology, Sparks, MD, USA⁷ US Geological Survey, Blacksburg, VA, USA⁸ US Geological Survey, LaCrosse, WI

ABSTRACT- A draft guide for conducting laboratory toxicity tests with glochidia and juvenile mussels in water-only exposures is being balloted through ASTM Committee E47 on Biological Effects and Environmental Fate. The draft guide describes procedures for collecting adult mussels to obtain glochidia and to propagate juvenile mussels for testing. Toxicity tests with glochidia are typically started within 2 h after glochidia are isolated from the gill of female mussels. The test endpoint for glochidia is survival (viability) as determined by shell closure after the addition of a solution of NaCl. For most species, the duration of a toxicity test with glochidia is up to 24 h with survival measured at 6 and 24 h; however, longer exposures may be appropriate for glochidia of some species. Acceptable control survival is >90% at the end of toxicity tests conducted with glochidia. Toxicity tests with juvenile mussels are typically started with organisms <5 d after release from the host fish; however, some toxicity tests are started with 2- to 4-month-old juvenile mussels. Acute toxicity tests with juvenile mussels are typically conducted for 96 h with survival measured at 48 and 96 h. Chronic toxicity tests started with 2- to 4-month-old juvenile mussels have been conducted for 21 to 28 d with measures of survival (based on foot movement) and growth (shell length). For tests conducted with juvenile mussels, acceptable control survival is >90% at the end of tests conducted for 96 h and is >80% at the end of tests conducted for 10 to 28 d. Early life stages of mussels of most species tested are more sensitive to some metals and ammonia in water exposures compared to many commonly tested species of other invertebrates, fish, or amphibians that are commonly used to establish USEPA Water Quality Criteria (WQC). Importantly, results of these previous studies indicate that WQC for several individual chemicals established for the protection of aquatic organisms may not be adequately protective of sensitive stages of freshwater mussels.

Key words: mussels, glochidia, standard