Doing the work catfish won’t do.
That certainly seems to be the case here, but it's true that bull sharks have been found as far north up the Mississippi as Cairo, Illinois, having swum up from the gulf. They've been found up to 4,000 km inland up the Amazon, and are quite tolerant of freshwater. They're not uncommon here (Louisiana) in the brackish to fresh waters of the Atchafalaya basin, and after Katrina, a number were observed in Lake Pontchartrain.
Didn’t Al Gore warn us things like this would happen if we didn’t switch to those squiggly lights?