Meeting Abstract
Anthropogenic chemicals have been shown to negatively impact freshwater organisms at sublethal concentrations. The effects of those chemicals is dependent upon several factors, including the duration of exposure. Longer exposure periods have the potential to cause both different and more harmful impacts to organisms than that of shorter exposure events. Most pollutants move through the environment in a pulsatile fashion so the concept of duration of exposure is complex and dynamic. Additionally, the toxicokinetics of some pollutants may not cause impairment following a brief exposure. To begin to understand how duration and the pulsatile nature of exposure interact to produce harmful effects in organisms, female Orconectes virilis crayfish were exposed to a solution containing sublethal concentrations of atrazine, an herbicide commonly used in agriculture. Crayfish were exposed for 1, 2, or 3 day periods within flow-through experimental streams. Immediately after the exposure period, crayfish fought an unexposed opponent in a 15 minute fight assay. These fight trials were recorded and later analyzed using an ethogram from Bergman and Moore (2003). Results indicate that exposure to atrazine significantly affects crayfish aggressive behavior. Results also indicate differences in aggressive behavior among the three duration treatment types.
