The fishery in Flathead Lake changed dramatically over the last decade. Since the last co-management plan was written in 1989, kokanee salmon have disappeared from Flathead Lake despite a 5-year effort to recover them. Mysis shrimp, first noted in Flathead Lake in 1981, strip zooplankton from the upper waters of the lake and serve as food for deep water fish such as lake trout and lake whitefish. Lake trout have increased in numbers and now make up most of the recreational fishery. Lake whitefish are also very numerous. Native species such as bull trout and westslope cutthroat trout have declined. With the establishment of Mysis and growth of the lake trout population, we have increased angling limits on lake trout and decreased limits on native trout. These limit changes illustrate the strategy followed by Montana Fish, Wildlife & Parks (FWP) and the Confederated Salish and Kootenai Tribes (CSKT) to address increasing numbers of nonnative fish and decreasing numbers of native fish. The lake's food web has been unstable, which means future management needs to be flexible and based on "adaptive management". Adaptive management emphasizes the application of new knowledge and techniques as they become available. Through adaptive management, actions can be adjusted as new information comes to light.