https://www.nytimes.com/2018/05/25/books/review/the-truth-ab...
And there's a post from 5 years ago called Pablo Escobar’s hippos: A growing problem. https://news.ycombinator.com/item?id=8949017
And finally there's the infamous plan to raise hippos in Louisiana: https://news.ycombinator.com/item?id=11321495
I guess we like our hippos.
But the study of castrating 10 males work almost perfectly and they showed less aggression... in fact the females were more likely to bully and harass castrated males. So not all is lost but they are still a challenge.
It’s actually not that hard to chemically castrate both males and females.
Governments worldwide make hugely unpopular decisions all the time, and often against the interest or will of the majority. It's strange that for something as trivial officials would take precautions.
You don`t have to shoot all of them. Just allow hunters to kill like 50 of them, and with the money from the licenses, capture other 30 or so and send them to zoos or back to africa in their native enviroment.