I'm not sure what native fish they say are getting outcompeted. Tilapia are basically a filter feeder so I guess they are talking about fecundity. Now, that might be possible in Southern Miss. but in Northern Miss. they wouldn't survive the winters. It sounds like a "one size fits all" law.

I guess they could be talking about predators switching over to tilapia instead of eating other forage fish and getting the predator/prey relationship out of balance. That might make sense.

Texas sorta regulates Grass Carp. You have to get a permit and the TPWD makes a phone call and asks if you are sure they can't get out of the pond. The TPWD has stocked tilapia in several power plant lakes where they overwinter. I'm not aware of any problems but I don't keep up with that kind of stuff.

I think Dennis's comparison to the Snakehead is a little over the top.