Lake Naivasha, northwest of Nairobi, Kenya is becoming increasingly unnavigable. Water hyacinth, the world’s most widespread invasive species, is blanketing the lake, choking its fish and leaving people stranded.
“Sometimes it becomes very serious,” says Simon Macharia, a local fisherman, about the weed problem. “There was this incident where fishermen were trapped by hyacinth inside the lake for three days. We had to seek help from the government (who) used a helicopter to rescue them.”
Macharia says that some days he’s simply unable to fish on the lake because of the plant. When he does, he can lose his nets underneath the floating weed, incurring costs while preventing him from earning that day. Water hyacinths also cover the surface, cutting off sunlight, outcompeting other plant species and starving water of oxygen. That means there are fewer fish for Macharia to catch in the first place.
The problem is so vast it can be seen from space. It also threatens the …