Rusty crayfish (Orconectes rusticus) are invasive in the upper Midwest United States. They often reach high densities and negatively affect native crayfish species, aquatic macrophytes, benthic invertebrates, and some fish populations. However, in some lakes rusty crayfish do not achieve high densities and do not negatively affect native biota. We conducted a whole-lake experiment designed to remove rusty crayfish from Sparkling Lake, a part of the North Temperate Lakes LTER site in Vilas County, Wisconsin. Crayfish were removed by trapping throughout the summers of 2001-2008, and sport fish regulations were also changed to increase fish predation on crayfish. Our objectives were to 1) reduce the rusty crayfish population; 2) evaluate the responses of native crayfish, aquatic macrophyte, aquatic macroinvertebrate, and fish communities to rusty crayfish removal; 3) determine if mechanisms exist that could force rusty crayfish to remain at low densities following the cessation of the removal program. The removal effort in each year has been far above that required to achieve maximum sustainable yield, resulting in a drastic reduction in the rusty crayfish population. Native crayfish populations have recovered somewhat, although not to historical levels. Percent macrophyte cover has increased throughout the lake. Macroinvertebrate response has varied among taxonomic group, with few orders (e.g., trichoptera, gastropoda) increasing in density and others (e.g., ephemeroptera, diptera) decreasing in density as rusty crayfish density has declined. The density of bluegill (Lepomis macrochirus) and pumpkinseed (Lepomis gibbosus) sunfish has increased. Fecundity (eggs/female) of rusty crayfish has declined, indicating the potential for a depensatory response to over-exploitation. We continue to study the rusty crayfish population as well as other components of the ecosystem to determine if in fact a regime shift has occurred. This experiment has implications for restoration of other invaded lakes, as well as for invasive species prevention efforts.