Grass carp threaten Great Lakes

As many as 45 grass carp were caught in the Great Lakes between 2007 and 2012, a new study finds. Grass carp, a plant-eating species of the invasive Asian carp family, have also been found spawning in Lake Erie and its many tributaries. The study was published in the Canadian Journal of Fisheries and Aquatic Sciences. Though fears over invading Asian carp have largely centered on bighead and silver carp -- which gulp down large amounts of plankton, the all-important food-source foundation for a healthy aquatic ecosystem -- the new study suggests conservationists should pay attention to grass carp too. Grasses are also an important nutritional source for native fish species, and as its name suggests, grass carp could prove detrimental in that department. The U.S. government has already spent upwards of $200 million trying to slow the encroachment of Asian carp into the Great Lakes. Many worry their growing presence will turn the Great Lakes into one giant carp pond -- ruining ecological diversity and the multi-billion dollar fishing industry in the region. Regional authorities remain in discussion with federal agencies over further mitigation efforts. But elsewhere, grass carp are being used to eradicate another nuisance species. In New Fairfield, Conn., town officials introduced a non-breeding version of the grass carp to prey on an infestation of Eurasian watermilfoil in a local pond. "It's been very successful there," town leader Susan Chapman told The News-Times of Danbury. Grass carp were originally considered important by aquatic farmers in the South for their usefulness in pond maintenance.