During the filling-up phase of the lake, the water was high in nutrients coming from decomposing, inundated vegetation, creating a thick layer of fertile soil on land that became the lake bed. As a result, the
ecology of Lake Kariba is vibrant. A number of
fish species have been introduced to the lake, notably the
sardine-like
kapenta (transported from
Lake Tanganyika), which now supports a thriving commercial
fishery. Other inhabitants of Lake Kariba include
Nile crocodiles and
hippopotamuses.
Gamefish, particularly
tigerfish, which was among the indigenous species of the Zambezi river system, now thrive on the kapenta, which in turn encourages
tourism. Both Zambia and Zimbabwe are now attempting to develop the tourism industry along their respective coasts of Lake Kariba.
Fish eagles,
cormorants and other water birds patrol the shorelines, as do large numbers of
elephants and other big game species including lion, cheetah, leopard, buffalo and a myriad of smaller plains game species. The southern
Matusadona National Park was once a haven for black and white rhinoceros, but recent poaching activity has dramatically reduced their numbers. ==Protected areas==