Asian carp species, from top, silver, bighead, and grass lay alongside each at a market in Springfield, Ill. Scientists say grass carp have invaded three of the Great Lakes and pose a significant environmental risk. The voracious grass carp is among four Asian carp species threatening to reach the world’s largest surface freshwater system. Like other Asian carp, some escaped into the Mississippi River and have migrated northward toward the Great Lakes. Article Continued BelowIt has long been known that at least a small number of grass carp were in the lakes, Gaden said. Grass carp reared in hatcheries, which some states allow, are supposed to be sterilized before being released into the wild.

Source: thestar January 28, 2017 02:52 UTC