RP8 Ecotoxicology of Agrochemicals and Pharmaceuticals
Thursday, 17 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(DIL-1117-840076) Atrazine increases burrowing in the freshwater clam, Corbicula fluminea.

Dillon-White, M¹, Flynn, K¹, ¹ Adelphi University, Biology Department, Garden City, New York, USA

ABSTRACT- Atrazine, the most commonly used herbicide in the U.S., is suspected of imitating estrogen and possibly changing burrowing behavior of freshwater clams. To assess this, three tanks with atrazine-contaminated water, at concentrations analogous to 0.1, 1, and 10 times the maximum EPA level for aquatic ecosystems (1.5, 15, and 150 ug/L, respectively) were set up. Estradiol at 100mg/L and the solvent alone were positive and negative controls. The solvent was no more than 1 mL 70% ethanol in 30L tanks. In each, six laboratory-adapted clams were placed on a 7 cm gravel surface and monitored for 72 hours. Clams were classed every 6 hours as completely, partially, or not burrowed and tanks were ranked by the percent of animals completely burrowed at each time. One-way analysis of variance (ANOVA) revealed a significant difference in percent burrowed among the treatment groups (p<0.001). Post hoc t-tests compared each treatment group to control ands estradiol, mid-, and high- atrazine groups were significantly different (p<0.005). The estradiol group burrowed 72% more than control, and mid- and high- atrazine groups burrowed 44 and 103% more respectively. This data suggests that temporary exposure to ecologically-relevant concentrations of atrazine considerably effects behavior in clams.

Key words: Corbicula fluminea