Movement of triploid grass carp in the Pee Dee River

r NORTH CAROLINA Fisheries Research Fact Sheet Movement of Triploid Grass Carp in the Pee Dee River July 2017 The N.C. Wildlife Resources Commission recently conducted a track¬ ing study on the Pee Dee River to better understand the movements of Grass Carp stocked into a riverine system. Grass Carp are efficient consumers of many types of aquatic vegetation and are often used to control nuisance or invasive aquatic plants such as hydrilla. However, Grass Carp are non-native and can negatively impact native plant, fish and bird species by directly removing desired aquatic vegetation within the waters stocked as well as adjacent waters if they escape. Because of this, all Grass Carp stocked into North Carolina waters must be certified as triploid (sterile) and a permit from the NCWRC is required to stock public waters, ponds greater than 10 acres, or more than 150 triploid Grass Carp. In 2010, hydrilla was discovered in the Pee Dee River just downstream of Lake Tillery Dam, which is operated by Duke Energy (Duke). Hydrilla has been known to cause operational problems with hydropower plants and Duke has an aggressive aquatic vegetation control program for its res¬ ervoirs. In 2014, Duke submitted a permit request to stock triploid Grass Carp into the approximately 21 -mile reach of river between Lake Tillery Dam and Blewett Falls Lake. Because the NCWRC had not previously permitted Grass Carp stockings in riverine systems due to movement con¬ cerns, Inland Fisheries stafF partnered with Duke to try to address some of these concerns. Project Objectives: • Determine Grass Carp movement patterns in the Pee Dee River and its major tributaries (Rocky River and Little River) downstream of Lake Tillery Dam. • Monitor for Grass Carp escapement through Blewett Falls Dam into the coastal Pee Dee River. A typical Grass Carp used to help control nuisance aquatic vegetation (Photo by Melissa McGaw/NCWRC). 0 125 25 5 Approximate receiver location sites in the Pee Dee, Rocky, and Little rivers (map by Lawrence Dorsey) Blewett Falls Dam, shown during a flood in April 2017. There were 68 days of spillover here during the study period (Photo by J. Dycus, Duke Energy) N.C. Wildlife Resources Commission Inland Fisheries Division www. nc wi Id lif e . org