First, the Giant Leaping Attack Sturgeon epidemic sprung up in the Eastern Gulf of Mexico. Now they've found a freshwater ally in the Big Muddy:

A Huge, Boat-Hurdling Carp Is No Mississippi Fish Story

I'd heard of the imported carp possibly getting into the Great Lakes, to which they're well-suited, and causing problems. But now they've taken to jumping into boats and hitting people in the face.

Now a more recent arrival, the black carp, is stirring alarm from New Orleans to Ontario. Also known as the snail carp and the Chinese roach, the black carp is a bottom-sucking ogre that can grow five feet long and up to 150 pounds. It gorges on mollusks — including parasite-infested ram's horn snails, which can populate ponds and infect the catfish with wormy yellow grubs. Teeth in the back of its throat grind up its prey like garbage disposals.

If this one escapes and takes to leaping into boats, we're all in trouble.

(Thanks to the Linkmeister.)