Response of estuarine benthic invertebrates to field applications of insecticide

Abstract The response of estuarine invertebrates to the neonicotinoid insecticide imidacloprid following field applications in Willapa Bay, Washington (U.S.A.) was examined using Principal Response Curve (PRC) Analysis. A total of 60 analyses was conducted to examine responses of six taxonomic assemblages (polychaetes, non-juvenile polychaetes only, mollusks, non-juvenile mollusks only, crustaceans, and all invertebrates combined). Eight trials were conducted among five sites over the course of three years. Five of the eight featured a liquid formulation of imidacloprid and three a granular formulation. Both the response and treatment effects were significant (p