More weed-eating carp for Santee Cooper lakes

The non-native fish species was introduced 35 years ago to control the spread of aquatic weeds, particularly hydrilla, that can inhibit boating, fishing, and electricity generation in the economically significant Santee Cooper lakes.

Last year, 11,025 grass carp were added to the lakes, but aquatic weeds still grew dramatically, said Casey Moorer of the Biological Services unit of Santee Cooper, the state-owned utility that manages the lakes.

This year’s stocking is intended to raise the population to 40,000 for a ratio of one grass carp per 4 surface acres of water.

The council and the state Department of Natural Resources are responsible for the management of nuisance aquatic plants in the state’s public waters.

Each year they produce a statewide draft plan that identifies aquatic weed problem areas, prescribes management strategies, and determines funding requirements.

This year’s plan authorizes the stocking of additional grass carp in 12 lakes across the state, among other management strategies such as applying herbicides and releasing giant salvinia weevils in localized areas as needed.

The draft plan for 2024 was posted online and 85 written public comments were received.

In addition, retired DNR employee Bob Perry spoke “as a private citizen and a specialist in aquatic biology” during the council’s 144th meeting, which was held Wednesday, March 6, at Santee State Park.

Perry urged the council to reduce its stocking plans by about 200 fish, primarily to benefit waterfowl hunters.

Moorer replied that the proposed number “was a data-driven decision” that took into consideration both historical data and the possibility that a major storm could raise carp mortality rates.

“We cannot predict what Mother Nature is going to hand us,” she said.

The council decided not to change its plan for the number of grass carp to be stocked in the Santee Cooper lakes.

They made only one significant change from the statewide draft plan. After further conversations with Dominion Energy and the DNR staff, they reduced the number of grass carp that will be stocked into Lake Murray near Columbia.