I think its nonsense to say that if you have cats you wont have prey fish, there is a balance found. Big cats are in Bluebell Lakes yets all hold good numbers of Tench, Bream, Roach , Perch etc and I've seen these prey fish masses on sonar in the winter so I know for a fact they are rich in prey, despite holding many huge cats, many!
I was a young angler when they used to say kill Pike because they eat everything, I left one on the bank then thought hang on this is nonsense I'm never doing that again. It was ignorance on the part of the clubs or whoever was supposed to be running the venue. Predators will go for the weak first and foremost and that can be seen as a good thing for a healthy population.
Biggest threat to prey fish is Cormorants, carp Otters.
I'm not a cat fan at all btw