Freshwater mussel die‐off attributed to anticholinesterase poisoning

Abstract

In 1990, we investigated a die‐off of freshwater mussels in north‐central North Carolina. An estimated 1,000 mussels of several species were found dead or moribund, including about 111 Tar spinymussels (Elliptio steinstansana) a federally listed endangered species. The die‐off occurred during a period of low flow and high water temperature in a stream reach dominated by forestry and agriculture. Pathological examinations did not show any abnormalities and indicated that the die‐off was an acute event. Chemical analyses of mussels, sediments, and water revealed no organophosphorus or carbamate pesticides. Cholinesterase activity in adductor muscle from Eastern elliptios (Elliptio complanata) collected at the kill site and downstream was depressed 73 and 65%, respectively, compared with upstream reference samples. The depression is consistent with a diagnosis of anticholinesterase poisoning. This is the first documented case in which cholinesterase‐inhibiting compounds have been implicated in a die‐off of freshwater mussels.

Cholinesterase and glutathione‐S‐transferase activities in freshwater invertebrates as biomarkers to assess pesticide contamination

“…Two studies report high levels of ChE inhibition followed by episodes of acute contamination: Fleming et al [105] reported the Swift Creek die-off in North Carolina, USA, of the freshwater mussel E. complanata (the die-off was caused by an anticholinesterase compound, thought to be an OP or carbamate pesticide) while Escartin and Porte [36] observed a 55% increase in the inhibition of AChE, in the crayfish Procambarus clarkii, following the application of fenitrothion on Ebro Delta (Spain) irrigation channels. In the context of pesticide contamination assessment, several studies are found in the literature: Robillard et al [16] exposed the freshwater mussel Anodonta cygnea in reference and contaminated sites (in an agricultural zone, contamination with triazine residues) in the Sarthe region of France.…”

Field Studies on Exposure, Effects, and Risk Mitigation of Aquatic Nonpoint‐Source Insecticide Pollution: A Review

“…The same applies to die‐off events of freshwater fish reported from Hungary with pyrethroids as the potential cause (Sályi and Csaba, 1994). Fleming (1995) investigated a freshwater mussel die‐off and measured reduced cholinesterase levels in mussel ( Elliptio complananta ), although no anticholinesterase chemicals were detectable. The lack of exposure data in all these studies makes a direct link of observed effects to contamination impossible.…”

Acetylcholinesterase Inhibition in the Threeridge Mussel (Amblema plicata) by Chlorpyrifos: Implications for Biomonitoring

“…Activity of AChE in the anterior adductor muscle (Fleming et al, 1995;Mohan et al, 1987) of A. plicata was analyzed based on the modi"ed method of Ellman et al (1961). Tissues were placed in Trizma bu!er (1% Triton X-100) at a ratio of 1 : 25 (w : v) and homogenized with a metal-bladed homogenizer.…”

“…For example, Fleming et al (1995) attributed the mortality of approximately 1000 freshwater mussels (Elliptio spp.) in Swift Creek, North Carolina, to organophosphorus (OP) and carbamate insecticides that entered the stream.…”