Fort Mill Times

More fish dumped in lake to battle hydrilla

Another batch of grass carp has been poured into Lake Wylie in a fight lake experts say they’re winning.

The Lake Wylie Marine Commission and Duke Energy released 300 more fish into the water May 15. Carp stockings are a way to prevent invasive plant species, particularly hydrilla.

In 2007, estimates put the hydrilla infestation at close to 100 acres on Lake Wylie. Tubers below the surface were thought to be even more widespread. The Lake Wylie Marine Commission, Duke Energy and South Carolina Department of Natural Resources partnered to dump the first 500 grass carp into the lake in 2008.

Within five years, hydrilla was down to about 100 square yards.

“The carp that we have released before are really working,” said Robert Biggerstaff, who with fellow commissioner George Medler heads up the invasive species program for the marine commission.

Only sterile carp are used, to prevent that species from spreading. Restocking is needed annually, as about 25 percent of the carp die.

Jennifer Jabon, spokeswoman for Duke, said the annual fish releases are taking a toll on the hydrilla. Hydrilla can grow up to a foot per day and tubers can remain in wet soil for years. Early in the carp stocking efforts, experts warned that inaction could have the grass overtaking waterways and rendering some areas useless for recreation boat traffic.

“The hydrilla population in Lake Wylie has been successfully reduced to an extremely low level and continues to decrease each year,” Jabon said.

The fish eat other grass-like plants, too.

“Regarding other species, we understand alligator weed continues to be an aesthetic concern in the South Fork river arm of Lake Wylie,” Jabon said.

There aren’t large weed beds as observed in years past. Annual stocking efforts will continue.

“The results of our hydrilla management efforts have been excellent, and the hydrilla population is under control,” Jabon said.

John Marks •  803-831-8166