The effects of atrazine on agonistic behavior in crayfish (Oronectes virilis) in a dynamic system

Abstract

Atrazine is the most commonly found herbicide in groundwater in the United States. Its adverse effect on aquatic organisms is well-researched. This experiment looks at how atrazine effects the agonistic behavior of Orconectes virilis in a dynamic system. We expected the atrazine-exposed crayfish to be less aggressive and therefore less successful in agonistic encounters with native crayfish. Crayfish of similar size were paired together to engage in a recorded fight, one having been exposed to 200 ug/L atrazine for 24-hours and one just to standard stream conditions. We found no statistical evidence to support our hypothesis that atrazine lowers the aggressive behavior in O. virilis. Regardless of our results, there is enough supporting evidence to show how atrazine negatively affects not only crayfish, but all levels of aquatic ecosystems, and it should not be used as heavily as an herbicide in the United States.