[Science] Hippos poop a huge amount of silicon every day – and it’s a good thing – AI

Hippos are living silicon pumpsAnn and Steve Toon/Getty By Ruby Prosser ScullyBy eating huge amounts of grass and then defecating in water, hippos are acting like living silicon pumps – and the health of their habitat may depend on it. Every evening, hippos eat around 40 kilograms of grass and other plants rich in silicon dioxide – also known as silica – only to spend the following day lazing around in the water where they digest and excrete it. While researchers have previously studied the role hippos play in moving nitrogen, carbon and phosphorus around their ecosystem, it has been unclear whether they also influence silicon in their habitat. To find out, Jonas Schoelynck at the University of Antwerp, Belgium, and his colleagues studied the silicon levels in a hippo-dominated ecosystem in south-western Kenya. In one 250-metre stretch of the river Mara, they spotted up to 80 hippos. Advertisement Read more: Ancient hippo-like reptile was a giant to rival the dinosaurs Analysing dissolved and particulate silicon in the river revealed that the hippos transported a total 0.4 tonnes of silicon a day – that’s 76 per cent of the total movement of silicon throughout the ecosystem. “Hippos act as a kind of conveyor belt, transporting silica from land to water,” says Schoelynck. This silicon pump in hippo form is vital to the ecosystem, because single-celled algae in the water need this element, and algae provide food for the other plants and animals in the waterways, Schoelynck says. But hippos have been killed or driven out from most of the rivers that lead into one of Africa’s great lakes, Lake Victoria. If populations shrink further, the amount of silicon pumped into waterways will diminish, and the important plants and fish there could be in jeopardy, says the team. Journal reference: Science Advances, DOI: 10.1126/sciadv.aav0395 More on these topics: animals ecology