Asian carp invade eastern South Dakota rivers
SIOUX FALLS (AP) — Asian carp are invading the rivers of eastern South Dakota.
Massive floods in 2010 and 2011 gave the carp an opportunity to spawn more successfully and move up the Missouri River and its three eastern South Dakota tributaries, creating one of the largest annual classes of two species of Asian carp, big head and silver carp, ever seen in the Missouri basin, the Argus Leader reported in a story published Sunday.
Those fish are old enough to reproduce, and that concerns the state Game, Fish and Parks Department.
"They could absolutely outcompete any other species," said the department's aquatic invasive species coordinator, Mike Smith.
The takeover has happened in the Illinois River south of the Great Lakes, where Asian carp now make up about 95 percent of that river's biomass, Smith said.
In South Dakota, the carp were able to invade all of the James River within the state and have been found all the way up to Jamestown, N.D. In the Big Sioux and Vermillion rivers, carp have reached as far north as Sioux Falls and Lake Vermillion. The species was stopped only by the Sioux Falls and Vermillion dams.
"Those are the only two barriers standing between Asian carp and spreading north," said GFP regional fisheries manager Todd St. Sauver.
The carp invasion has prompted GFP officials to close almost all flowing water below Sioux Falls on the Big Sioux and Vermillion Rivers and all water in the James River watershed to bait capture in an effort to prevent their spread. The department also created new regulations aimed at preventing the spread of aquatic invasive species and has started an advertising campaign aimed at educating outdoors enthusiasts about them.
But that might not be enough.
A few years ago, St. Sauver said, a pair of anglers started to fish below the dam and caught what they thought was a salmon. They then went above the dam, where they were checked by conservation officers, who discovered a live Asian carp in their boat's live well.
"The one thing we can't control is people. If someone decides to move one of these things, we won't be able to stop them," St. Sauver said.
If Asian carp do get above the Vermillion and the Sioux Falls dams, they could infest almost every water system in eastern South Dakota, officials said.