A Comparison Of Two Necturus maculosus Populations In Northeastern Ohio Prior To Lampricide Treatment

Abstract

The invasive sea lamprey (Petromyzon marinus) is capable of causing significant ecological and economic damage in the Great Lakes region. Since 1958, the chemical pesticide 3-trifluoromethyl-4-nitrophenol (TFM) has been used to control lamprey populations. While this pesticide is largely thought to specifically target the lamprey, studies suggest that a number of non-target species suffer from continued exposure to TFM. TFM has pronounced lethal effects on the common mudpuppy (Necturus maculosus), a large, long-lived, and fully-aquatic salamander. As a predator, Necturus plays an important ecological role in the rivers surrounding the Great Lakes. This study takes a closer look at how Necturus populations are affected by TFM. The data suggest that the mudpuppy population in the Grand River is more disturbed than the one in the Ashtabula River. This is supported by the following: The Grand River had a lower population estimate than the Ashtabula River. The Grand River had fewer nests and fewer reproductively active males, suggesting that its breeding cycle is not as healthy as the Ashtabula’s. A higher percentage of the Grand River mudpuppies were too small to receive PIT tags, suggesting that this population is composed of younger individuals.Before the initial TFM treatment in the Grand River in 1987, the mudpuppy population was estimated to be 803 mudpuppies /km. Following the first treatment, the Grand River’s population estimate dropped to 333 mudpuppies/km (Matson, 1990).