The intake of water traps aquatic life in the cooling system. The cooling system is installed with a filter to prevent large objects or fish from getting pulled into the system. Some small aquatic life fit through the filters and are killed once they enter the cooling system. Other aquatic life becomes trapped in the filters. The force in which water is pulled into the cooling system, traps larger aquatic life against the filters. Marine mammals that breathe oxygen often drown while trapped against the cooling system filters. The cooling systems trap, harm and kill fish, larvae, plankton and marine mammals. Even endangered species become victims to the once through cooling systems.