Complex sentence: The federal government in the U.S. is concerned that release of this fish into U.S. waters could harm the environment, and this fish could prey upon native species, especially in southern areas such as Florida, Texas, and Hawaii.
Split into simpler sentences: The federal government in the U.S. is concerned that release of this fish into U.S. waters could harm the environment. This predator could harm native species, especially in southern areas such as Florida, Texas, and Hawaii.