Lake Alaotra

Lake Alaotra (Malagasy: farihin' Alaotra, [faˈrihin ˈaloʈʂə̥]; French: Lac Alaotra) is the largest lake in Madagascar, located in Alaotra-Mangoro Region and on the island's northern central plateau. Its basin is composed of shallow freshwater lakes and marshes surrounded by areas of dense vegetation. It forms the center of the island's most important rice-growing region. It is a rich habitat for wildlife, including some rare and endangered species, as well as an important fishing ground. Lake Alaotra and its surrounding wetlands cover 7,223 square kilometres (2,789 sq mi), and include a range of habitats, including open water, reedbeds, marshes, and rice paddies. The lake itself covers 900 km (350 sq mi). Lake Alaotra was declared a wetland of international importance under the international Ramsar Convention on February 2, 2003.

The longfin tilapia (Oreochromis macrochir) was introduced into Lake Alaotra from the mainland in 1954 and proliferated quickly. By 1957, it provided 46% of the catch, perhaps because it was moving into an empty ecological niche as a phytophagous species.