Yeah, they put most of the Cichlids in Lake Victoria on the endangered list within a few years of being introduced.
But thats an effect you are going to get whenever you add a large apex predator into an enviroment which previously didnt have them, fish and prey animals evolve to co exist with their predators over thousands of years and have adapted in ways that allow the majority to not be eaten so there are always enough left to breed and continue the species, when a new predator is introduced they cant adapt quick enough and get wiped out. The same thing happened in America with the snakeheads in Maryland and even here in England with Zander in the fens of Cambridge and Norfolk.