Meeting Abstract
Anthropogenic toxins in solution have detrimental effects on aquatic organisms. Within lotic systems, these toxins are dispersed and move through the environment due to turbulent mechanics. The physical properties of a habitat (flow speed, substrate, and in particular obstacles in the flow) can alter, enhance, or diminish the dynamic concentrations impacting both physiological and behavior functions of key organisms. This study was designed to quantify how the changes in dynamic toxic exposure, due to turbulent flow, will impact behavioral and physiological responses of a keystone species. Crayfish (Orconectes virilis) were exposed to sublethal levels of the insecticide Carbaryl in a naturalistic flow through stream. Crayfish were placed at different distances away from a source of pollution and either upstream or downstream from an obstruction. We quantified the influence of turbulent flow on the distribution of toxins in the experimental flow channel before exposing crayfish. After 48 hours of exposure to an insecticide, crayfish were evaluated on their ability to locate a food odor in a Y-maze arena. In addition to this behavioral assay, the physiological impact of exposure was examined by comparing the hepatosomatic index (HSI). Results indicate that the addition of turbulence alters the dynamic fluctuations in toxic concentrations, thereby generating significant differences in physiology (HSI) of exposed animals between exposure paradigms. Differences in behavior also appear to be present in the foraging ability test. The findings of this study indicate that exposure to toxins in a natural environment varies and this variance of exposure allows for animals to experience a range of exposures based on the environment.
