Terrance D. Hubert

Environmental Fate and Effects of the Lampricide TFM: a Review

Use of 3-trifluoromethyl-4-nitrophenol (TFM) is limited geographically to the Great Lakes basin where it is the principal agent used in control of the sea lamprey (Petromyzon marinus). It is clear from available data that TFM has effects on the environment, but the effects reported are transient. Individual organisms and aquatic communities return to pretreatment conditions after lampricide treatments have concluded. TFM is not persistent, is detoxified, and presents minimal long-term toxicological risk. TFM is relatively nontoxic to mammals. Treatment levels do not pose a threat to wildlife. However, TFM is an estrogen agonist and additional testing to define the nature and magnitude of this effect will likely be required. Because stream treatments are done on 3 to 5 year cycles, and exposures are limited to approximately 12 h, minimal risk to aquatic organisms is expected.

Liquid chromatographic determination of benzocaine and N-acetylbenzocaine in the edible fillet tissue from rainbow trout

A method was developed for determining benzocaine and N-acetylbenzocaine concentrations in fillet tissue of rainbow trout. The method involves extracting the analytes with acetonitrile, removing lipids or hydrophobic compounds from the extract with hexane, and providing additional clean-up with solid-phase extraction techniques. Analyte concentrations are determined using reversed-phase high-performance liquid chromatographic techniques with an isocratic mobile phase and UV detection. The accuracy (range, 92 to 121%), precision (R.S.D., < 14%), and sensitivity (method quantitation limit, < 24 ng/g) for each analyte indicate the usefulness of this method for studies characterizing the depletion of benzocaine residues from fish exposed to benzocaine.

Evaluation of the short term 12 hour toxicity of 3‐trifluoromethyl‐4‐nitrophenol (TFM) to multiple life stages of Venustaconcha ellipsiformis and Epioblasma triquetra and its host fish (Percina caprodes)

The present study evaluated the risk of 12-h exposures of the lampricide 3-trifluoromethyl-4-nitrophenol (TFM) to multiple life stages of the federally endangered snuffbox (Epioblasma triquetra) and its primary host fish the common logperch (Percina caprodes) as well as a surrogate to the snuffbox, the ellipse (Venustaconcha ellipsiformis). Life stages examined included free glochidia, 1-wk juveniles, and adults of the ellipse; free glochidia, glochidia on host fish, and 1-wk juveniles of the snuffbox; and adult logperch. Larval sea lampreys were also tested alongside adult ellipse and logperch for direct comparison. Survival exceeded 82% among all life stages in both mussel species at levels up to 1.8 times what would be applied during treatments, suggesting that routine sea lamprey control operations would not adversely affect mussels. However, substantial mortality of adult logperch was observed at TFM concentrations typically applied to streams, and loss of host fish could adversely affect snuffbox reproduction. In addition, TFM had no significant effect on the number of glochidia that metamorphosed on adult logperch. Although the snuffbox is not likely to be acutely affected from sea lamprey control operations, mitigation efforts to minimize impacts to the host fish should be considered.

Uptake, Metabolism, and Elimination of TFM by Fish

The larval lampricide 3-trifluoromethyl-4-nitrophenol (TFM) has been used to control sea lamprey (Petromyzon marinus) in the Great Lakes basin for over 30 years. Studies have been conducted to (1) determine the nature and magnitude of TFM and TFM residues in fish fillet tissue under acute exposure conditions, and (2) determine the rates of uptake, elimination, and the nature and magnitude of TFM and TFM residues in fish tissues under subchronic exposure conditions. Data from these studies were submitted to the U.S. Environmental Protection Agency to support the reregistration of TFM. An historical perspective on the sea lamprey control program, data from previous research on the nature of TFM residues in fish, and the results of the studies conducted at UMESC are presented.