Hippo poop killing fish in African river: Study
While it is known industrial sewage can cause low oxygen conditions and kill fish, a Kenya-based study has found hippo waste can have a similar effect. About 4,000 hippos at Maasai Mara National Reserve add about 8,500 kg of partially digested plant material into Mara river each day, said researchers, who found 13 instances of fish kills over three years.