The distribution and zoogeography of lake trout, lake whitefish, and ninespine stickleback in Vilas and Oneida counties, Wisconsin
Populations of lake trout, lake whitefish, and ninespine stickleback are uncommon in the Mississippi-Missouri watershed, and in many lakes their origin (native, introduced or recently invaded) is unclear. In the Mississippi basin of northcentral Wisconsin at least eight lakes contained lake trout at some point during the last 80 years. In two of the lakes, Black Oak and Trout (Vilas Co.), the lake trout are probably native. Trout Lake also contains a native population of lake whitefish, and three ninespine stickleback have recently been captured there, the first record of the species in an inland lake in Wisconsin and only the fourth for the entire MississippiMissouri basin. There is some evidence that Trout Lake ninespine stickleback differ morphologically from the nearest other populations examined. Unlike in northeastern North America, the distributions of ninespine stickleback and two other deepwater species in the Mississippi-Missouri watershed are not strongly correlated with the former distribution of large proglaciallakes, suggesting active dispersal into the area following deglaciation . In addition to lake trout, lake whitefish, and ninespine stickleback, Trout Lake contains native populations of five other deepwater animals, giving it one of the most diverse deepwater assemblages in the Mississippi-Missouri basin. Future management of the lake should emphasize the preservation of this fauna , and particular effort should be made to prevent the introduction of rainbow smelt, which has become established in several lakes in the area .