Abiotic factors in a hippo environment?

You don’t get useful information from simply googling “hippopotamus environment”? I got a fair number of hits that seem like they’d lead you to useful information. I don’t know the answers off the top of my head.

Here is a chemical analysis of some waters in western Uganda with a large hippo population. It lists pH for some locations. The levels of phosphorus and potassium are extraordinarily high in hippo environments having slow water turnover because, well, hippos are prolific poopers.

There is some temperature information on some Ugandan lakes with hippo populations here, along with mentions of O2 content (though not actual measures).

This paper contains water quality information (including pH and O2) for many of the Ugandan lakes with hippo populations