Lake Chad
Lake Chad spreads between Chad, Niger, Nigeria, and Cameroon and is home to lions, crocodiles, hippos, and many other animals. Unfortunately, Lake Chad is drying up fast and there's no clear answer why. Climate change and irrigation methods are the usual suspects. However, other scientists maintain that the shrinking is not related to human causes at all. Regardless of the reason, Lake Chad has lost 90% of its water in the last 50 years, with no sign of recovery.