Check this out - easpecially the video. It would be too funny if it was not so sad for the ecosystems. Couldn't fish farmers use them to make food pellets?
http://www.canada.com/technology/Giant+leaping+Asian+carp+threaten+Great+Lakes/2463897/story.html
http://www.canada.com/technology/Giant+leaping+Asian+carp+threaten+Great+Lakes/2463897/story.html