Lake Superior other Great Lakes fish, populations have also been affected by the accidental or intentional introduction of foreign species such as the sea lamprey and Eurasian ruffe. Accidental introductions have occurred in part by the removal of natural barriers to navigation between the Great Lakes. Overfishing has also been a factor in the decline of fish populations. Lake Superior Lake Superior (; ), the largest of the Great Lakes of North America, is also the world's largest freshwater lake by surface area, and the third largest freshwater lake by volume. The lake is shared by the Canadian province of Ontario to
Lake Baikal the world's oldest lake – at 25–30 million years. It is the seventh-largest lake in the world by surface area. Like Lake Tanganyika, Lake Baikal was formed as an ancient rift valley, having the typical long, crescent shape with a surface area of . Baikal is home to thousands of species of plants and animals, many of which exist nowhere else in the world. The lake was declared a UNESCO World Heritage Site in 1996. It is also home to Buryat tribes who reside on the eastern side of Lake Baikal, raising goats, camels, cattle, sheep, and horses, where the