RALEIGH, N.C. (Dec. 17, 2018) — After the discovery of hydrilla in the Deep River, the N.C. Wildlife Resources Commission is asking people who boat, fish or swim in the river to help to help prevent the spread of this invasive aquatic weed.
Hydrilla is a highly invasive, nonnative plant that creates dense mats of stems and leaves on the water’s surface. A survey conducted by N.C. State University in 2017 confirmed the presence of hydrilla covering over 90 acres from N.C. Hwy. 22 in Highfalls in Moore County to U.S. Hwy 1 near Moncure, located in Chatham and Lee counties.
Hydrilla mats crowd out native vegetation, make boating difficult, and, ultimately, can harm fish and other aquatic organisms, and even birds, according to Brena Jones, an aquatic wildlife diversity research coordinator for the Commission.
“Hydrilla chokes our aquatic systems and destroys fish and other aquatic species’ habitats. It can lead to decreased levels of dissolved oxygen in the river which can suffocate fish, mussels, and other aquatic life, which is particularly concerning in this river, the home of the federally endangered Cape Fear Shiner,” Jones said. “Furthermore, hydrilla beds can harbor a cyanobacteria, which causes Avian Vacuolar Myelinopathy (AVM), a fatal disease that infects waterfowl and predatory birds, such as bald eagles.”
Hydrilla infestations can clog intakes in rivers and reservoirs that are used for drinking water supplies and irrigation, and can make fishing and boating almost impossible.
In addition to the ecological impacts hydrilla can have on a waterbody, the economic impacts of the weed can be just as significant, Jones added.
“Aside from impacts to both rare species and popular fishing and hunting targets, infested areas incur great expense because they must be treated to protect native resources and safe use for human communities,” Jones said. “A single location can cost anywhere from $50,000 to $400,000 for a single year of treatment and controlling hydrilla requires a minimum of seven to 10 years of treatment. What’s worse, eradication is difficult to impossible, so prevention and limiting spread are critical.”
To prevent the further spread of hydrilla and other harmful invasive species, at the conclusion of every outing on the water boaters and anglers should:
See the Four Steps to Stop the Spread of Aquatic Nuisance Species.
In the coming months, the Commission will work with the N.C. Aquatic Weed Program, the U.S. Fish and Wildlife Service, other state agencies and local stakeholders, to develop a management plan that addresses the infested areas and helps prevent hydrilla from spreading. The management plan will examine treatment alternatives and will include recommendations for the best course of action, along with monitoring guidelines.
Developing a plan that prevents the spread hydrilla is critical because the infested areas are home to the of the federally endangered Cape Fear Shiner. The Cape Fear shiner is a small fish species unique to North Carolina, found only in five counties —Chatham, Moore, Lee, Randolph, Harnett— inhabiting the Deep, Rocky, lower Haw and upper Cape Fear rivers.
For more information about hydrilla, as well as other aquatic nuisance species, visit the Commission’s Aquatic Nuisance Species webpage (ncwildlife.org/ans).
Jodie B. Owen
Download a high-resolution, printable version of a map depicting the hydrilla-infested areas on the Deep River. Map courtesy of Brena Jones