Exhaustive laboratory tests—more than 40 years’

worth—show that at the dose needed to eliminate

sea lampreys, TFM is nontoxic or has minimal

effects on aquatic plants, other fish, and wildlife.

The impact on non-target species can be reduced

by closely controlling the concentration of TFM

applied and by applying TFM during the right season

(after the spawning run, for instance). Studies

have also shown TFM to be nontoxic to humans

and other mammals. This compound is registered

as a lampricide by the U.S. Environmental

Protection Agency and Agriculture Canada and has

met or surpassed all criteria for application in Great

Lakes streams.