evidence: "I am the major bread-earner for the family, but my income is not enough to survive," said Mary Anyango, a fish-seller and mother of seven who lives in Dunga, a village on the Kenyan shores of Lake Victoria. [...] Lake Victoria is the world’s largest tropical freshwater lake and the largest lake in Africa. It lies in Tanzania, Uganda, and Kenya and supports the livelihood of 40 million people in the three East African countries. [...] "There are a lot of issues happening upstream", said Brian Waswala, a wildlife and landscape ecologist at Kenya’s Maasai Mara University. He told Al Jazeera that most of the freshwater feeding Lake Victoria comes via rivers in farming regions where agro-pesticides and fertilisers are used in large quantities to increase yields of produce such as coffee and tea.