Large lakes evolve continuously through interaction with the physical, chemical, and biological environments of the surrounding watershed and lakes. Recent evidence from Lake Tai shows global climate and sea level changes led to a major change in Lake Tai from brackish to a freshwater environment. Human activities in the last 50 years have had visible ecological and physical impacts on the lake. Increases in the use of the lake and its watershed over the last 10 years has resulted in accelerated eutrophication and elevated level the level of industrial pollutants.