Minnesota captures five invasive bighead carp in area river

MINNEAPOLIS (Reuters) - Five bighead carp have been captured in the past week in a river in Minnesota, a worrisome sign that the invasive fish species is making inroads in northern waterways, the state's Department of Natural Resources said on Tuesday. The fish were found in the St. Croix River, about 25 miles west of Minneapolis and the department was checking for any more of the fish in the waterway, it said. "This is the furthest upstream invasive carp have been detected in the St. Croix, and is about 7 miles north of the previous point," the department said in a statement. Silver and bighead carp are two of four species of invasive carp, known as Asian carp, that are threatening the Mississippi River and other native ecosystems, the department said. "They can grow to 60 pounds (27 kg), impacting the base of the food chain by consuming large amounts of plankton relied on by native fish," it said. Asian carp were introduced in the United States in the 1970s to control weed and parasite growth in aquatic farms. They managed to get into the Mississippi River and have been found as far north as Minnesota, the U.S. National Park Service has said. "Experts are worried that if these fish get into the Great Lakes, they may negatively affect the area's $7 billion a year fishing industry," the service said in an Internet posting. (Writing by Jon Herskovitz in Austin, Texas; Editing by Sandra Maler)