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

►We evaluate the risk of acute lampricide (TFM) exposure to the federally endangered piping plover. ►We examine TFM residue levels in water, sediment, and caged invertebrates before, during, and after a lampricide treatment. ►We estimate a safety factor of 85 for adult and 17 for juvenile piping plovers at TFM levels typically used to control sea lampreys. ►Adverse effects of acute TFM exposure to piping plovers from sea lamprey control operations are unlikely.