Evaluation of 3-trifluoromethyl-4-nitrophenol (TFM) residues following a lampricide treatment as a risk assessment to the endangered piping plover

Abstract

To evaluate the risk to the federally endangered piping plover (Charadrius melodus) from exposure to 3-trifluoromethyl-4-nitrophenol (TFM) during a sea lamprey control treatment we collected and analyzed a series of water, sediment, and aquatic invertebrate samples for the presence of TFM before, during, and after treatment of the Little Two Hearted River, Luce County, Michigan in July 2008. Results of the analyses in water showed the treatment resulted in a maximum concentration of 1.14mg/L TFM. Residues of TFM in water were greatest 50m east of the mouth (0.73mg/L TFM) and had decreased below detection at most of the sampling sites one day after treatment. Residues of TFM in sediment were greatest 50m east of the mouth (105ng/g TFM) with lower levels observed west of the mouth (3-5ng/g TFM) the day of the treatment. Residues decreased rapidly and were below detection in most of the samples the day after treatment. Residues of TFM in caged mayflies were greatest one day after treatment (3,193ng/g wet weight), decreased substantially by 4days after treatment (74ng/g), but were still present 8days after treatment (80ng/g). Based on results from this study the overall TFM exposure to adult piping plovers (0.425mg/kg) was 85 times less than the estimated No Observable Effects Concentration (NOEC) of 36mg/kg and was 17 times less than the NOEC for plover chicks (2.13mg/kg) indicating the risk from sea lamprey control operations would likely be minimal.