Selection Preference of Hyalella azteca in Response to Environmental Contaminants

Abstract:

Non-target organisms in aquatic environments are not only affected by lethal toxicity of contaminants, but also sublethal effects. Continuing to study the effects that sublethal contaminant concentrations can have on non-target species, specifically behavioral changes, can introduce new protocols and regulations into the field of toxicology. However, there is a lack of understanding of behavioral effects that can occur when organisms are exposed to sublethal concentrations. The objective of this study was to utilize a previously designed behavioral assay to monitor the avoidance behavior of Hyalella azteca when exposed to three different sublethal concentrations of bifenthrin. A behavioral assay was used to observe if H. azteca can avoid sediment containing concentrations of 10%, 25%, and 50% of lethal contaminant concentrations determined from 48 h toxicity tests. So far, H. azteca demonstrate a statistically significant preference for the uncontaminated sediment over the contaminated sediment at the LC50 and LC25 bifenthrin concentrations. These findings will be presented on April 23rd at the Sigma Xi Undergraduate Research Conference via a poster. If these findings prove that H. azteca avoid sediments that are contaminated with sublethal concentrations, it will demonstrate that pollution regulations based on lethal concentrations are not as protective as previously thought. Better understanding of contaminant influences on behavior will allow a broader understanding of the effects of contaminants in ecosystems and cause change through better regulations to protect aquatic ecosystems.