Use of esterase activities of the zebra mussel (dresissena polymorpha pallas) as a biomarker of organophosphate and carbamate pesticides contamination

Abstract

The inhibition of acetylcholinesterase (AChE) and carboxylic esterase (CbE) activities was measured in the zebra mussel, Dreissena polymorpha, in view of the possible impact of organophosphate and carbamate pesticides. Three experimental designs were performed: (a) in vitro studies in which the inhibition of both AChE and CbE activities was measured after incubation of homogenate of soft tissues of mussels with a range of organophosphate and carbamate insecticides, aldicarb, carbofuran, chlorfenvinphos, dichlorvos, dimethoate, malathion, parathion, tetrachlorvinphos, and the oxon of parathion and malathion (paraoxon and malaoxon, respectively); (b) in vivo assays with native mussels exposed to a carbamate pesticide, aldicarb; and (c) in situ studies of the level of esterase activity found in mussels collected on several stations on Lake Geneva. The results showed that the zebra mussel has a measurable, but low, level of AChE activity, and a higher level of CbE activity. However, this latter activity was not very sensitive to inhibition by these toxic compounds. Inhibition in the field was not demonstrated, but significant modifications of the protein content of the mollusks were shown. It was concluded that CbE was not a promising and reliable biomarker to assess the toxic effects of organophosphate and carbamate pesticides in the field. © 1996 by John Wiley & Sons, Inc.