Alligator Weed Remains a Big Problem for Tyrrell County
Published 8:50 pm Tuesday, January 14, 2014
Every community has problems big and small.
Each problem requires a certain type of action depending its size and scope.
Alligator Weed or alternanthera philoxeroides is an invasive aquatic plant native to South America.
Historical accounts note that it was spread though shipping lanes globally and locally into the southeastern United States in the late 1800’s acting as a stowaway in the bilge of large ships.
Reports available on the United States Department of Agriculture’s website and ncwater.org note that alligator weed stems are long, branched, and hollow. The leaves associated with the weed are simple, elliptic, and have smooth margins. Alligator weed flowers during the warm months of the year and has whitish, papery, ball-shaped flowers that grow on stalks. Alligator weed typically grows in floating mats along the water’s edge. Although it typically prefers fresh water, it can grow in brackish water, and can also grow and thrive on land.
Ncwater.org explains that alligator weed has a resistance to herbicides making it difficult to control. It also has the ability to reproduce from small stems or root parts. This makes it very hard to contain because the weed can spread by many methods such as birds and boat trailers. Small parts of the floating mats can even break off and drift to another location and continue to spread.
Ty Fleming is the Soil and Water Technician for Tyrrell County.
He notes that he has had firsthand experience with the problem.
“Because of its ability to spread easily, it is a real problem in Tyrrell County due to the many waterways being severely clogged with sediment and storm debris. The floating mats get stopped by fallen trees, debris, bottlenecks, culverts, pump intakes, and continue to spread until the waterway is completely covered from bank to bank,” said Fleming.
This causes flooding by impeding the water flow, which is crucial to the drainage of the county.
“The damage does not stop at just flooding, it depletes the water of oxygen used by fish and other aquatic animals. Thus it provides a perfect breeding ground for mosquitos, makes for navigational hazards for boaters, and is just aesthetically unpleasant, ”said Fleming.
In North Carolina, alligator weed is managed with the use of aquatic herbicides. In the coastal plain flea beetles have been released in North Carolina but their ability to control alligator weed is limited because the insect cannot withstand the winter.
Tyrrell County annually has funds allocated from the state and federal government, but it does not come close to the amount needed to achieve control. At least two applications of these herbicides are needed annually to truly manage alligator weed.
“In 2013, Tyrrell County had enough funding to spray around 12,000 feet of the Scuppernong River from the western county line to just north of the Cross Landing Bridge and the Town of Columbia and areas south of the Grindle Hill Canal, along the town waterfront towards Cypress Cove Marina were sprayed,” said Fleming.
The Tyrrell County Soil and Water Conservation District works directly with the North Carolina Department of Agriculture and gets allocated funding for county farmers and landowners to implement Best Management Practices through the NC Ag Cost Share Program.
Conservation practices such as the installation of flashboard risers, which work as water control structures, enable the farmer to not only control the water table in fields, but also keep the fertilizer runoff contained in the farm ditches. This helps prevent these nutrient rich waters from reaching the county’s waterways and allowing Alligator Weed to feed and thrive.
Tyrrell is currently working with the Albemarle Resource Conservation and Development Council on a Water Management Study, which is looking at dividing the county into sub-watersheds with the possibility of installing service districts for waterway maintenance, including the clearing and snagging of debris as well as additional funding for the spraying of this invasive aquatic species.
For more information on preventing and fighting this nuisance, please contact Ty Fleming with the Tyrrell County Soil and Water and Conservation District at the USDA Service Center in Columbia or call 796-3701 extension 3