Lake Erie Crabs

First it was the Loch Ness Toad, now another critter is found in a body of water where it really shouldn't be. From the Morning Journal:

"Rick Patterson of Lorain was fishing for perch off the pier near the Jackalope Bar and Rotisserie, when he saw something biting the minnow on his hook and reeled it in.
"What Patterson caught was a Chinese mitten crab." ...
"Dave Kelch, extension specialist with the Ohio Sea Grant Program of The Ohio State University Extension Service, drove to the pier yesterday to take a first-hand look at the crab." ...
"Kelch said the first sighting of two Chinese mitten crabs in Lake Erie was in 1973. A second Chinese mitten crab was found in the lake in 2005.
"'This is only the fourth one found in Lake Erie,' Kelch said." ...
"'The strange thing about this,' Kelch said, 'is that he (Patterson ) said he's always fishing out here and that he's seen a Chinese ore freighter (on occasion) sitting outside the harbor.'
"Kelch speculated that the crab could have been caught in the ballast water from the freighter's home port of Hong Kong and then dumped into Lake Erie. Ballast water balances the ship and is proportional to the weight of the load the ship is carrying."