Carp might prove to be part of the solution to toxic blue-green algae in Grand Lake St. Marys.  The fish can eat the algae without suffering its ill effects.  Many are concerned that Asian carp will overtake native prize fish species from Lake Erie through the northwest, but an OSU professor debunks this notion saying that water conditions are too cold for the species to spawn.  Grand Lake St. Marys is mentioned near the end of this article from the Columbus Dispatch:

"… Asian carps were introduced to Dabrowski’s native Poland without harmful consequences years ago, he said, to control algae and other unwanted life forms in certain containments.

"There are populations of Asian carp in Europe that are 40 years old and never spawned," he wrote.

Dabrowski dismisses the notion that an electronic barrier will keep the carp out of Lake Michigan. Once in that lake, it’ll be only a matter of time before a few reach Lake Erie.

However, because it’s unlikely they’ll reproduce, the carp won’t have a major impact on native fish, he said. What’s more, the cold conditions that prevail for much of the year in the Great Lakes generally won’t allow the carps that do get in to grow continuously to enormous sizes at which they can vacuum up the bottom of the food chain.

Although he says he’s "anti-carp" in areas where they have crowded out native species, Dabrowski said that in some situations – not excluding Grand Lake St. Marys – the carps might be part of a solution for the blue-green algae infestation.

"They can eat the blue-green algaes without becoming intoxicated," he said."