bullsharks can live in freshwater for long amounts of time. if it werent for all the damns we have on the mississippi wed find em here in st. louis. in 1920's they found a 11 foot bullshark in alton, illinois. 2300 miles away from the ocean. they live in lakes in africa and also deep in the amazon. one swam up a new england river way back and ate a few kids i think.