The largest lake in Africa needs hippo poop

We need to have a serious discussion about hippo poop.

I know it will be difficult because the words "hippo poo" will never be fun (I literally laugh when I write them), but it's actually an important part of the conservation puzzle on the Mara River, Kenya.

According to new findings published in Science Advances on Wednesday, hippos play a vital role in transporting silica from the soil to the water through their prolific stools. 880 pounds of silica are dumped daily into the Mara River by hippos, and this "biogenic silica stream" allows the base of the Lake Victoria food chain to thrive. If hippos were to disappear, the entire food chain would change without their regular deposits.

Jonas Schoelynck, a postdoctoral researcher at the University of Antwerp, was inspired by a presentation of the role of hippos in the Mara ecosystem and realized "they were dumping tons of droppings into the water while twisting them. their research. Previous research on the hippopotamus poop of the Mara River (it's really a thing) has shown that their prolific discharges – the average hippopotamus can deposit about 20 kilograms of poo a day – can cause massive death. fish in the Mara. But new discoveries show that what removes the fish also gives life to the diatoms of Lake Victoria, tiny algae that need silica to build their cell walls.

There is a good amount of silica available in savanna grasses around the Mara. And it turns out that hippos love to eat these herbs, eating more than 55 pounds a day. It's a lot of fodder, which means a lot of poo. Some find themselves on the ground because hippos have no scruples about shitting where they eat. The same is true for many other breeders. But as hippopotamuses spend half of the day in the water, about half of their stools also end up there.

Schoelynck and a team of researchers and park rangers from the Masai Mara National Reserve went out into the field to sample the poop water and the river and deconstruct what hippopotamuses were laying in. inside and beside the river. The results show that hippo poop (or "water management" as politicians so politely describe) is responsible for more than three quarters of the silica that ends up in the river .

"These studies show for the first time the role of large herbivores in transporting silica in plants to rivers and lakes," said Schoelynck. "Hippos act as a kind of conveyor belt carrying the silica from the earth to the water."

This silica-rich water eventually ends up in Lake Victoria where it allows the diatoms to flourish. Diatoms are responsible for extracting carbon dioxide from the air and forming the base of the food chain. The study notes that without hippos, the food chain would have shit literally and figuratively. Diatoms would become fewer. Nitrogen and phosphorus levels would be out of balance with silica, which could make blooms of deadly cyanobacteria more common. In fact, this has been happening since the 1980s, and research indicates that the decline in hippopotamus populations may be behind schedule.

"I actually hope that with my study, the hippopotamus is considered more important than just the tourist attraction," Schoelynck said.

Which yes. But also. Hippo poop.