NEWBERRY COUNTY — Hydrilla Verticillata, an invasive aquatic species, has been found in the Summerset Bay area of Lake Greenwood, members of concerned citizens group have been told.
Julie Davis, manager of Lake Greenwood, told attendees of the Jan. 19 Preserving Lake Greenwood meeting that hydrilla was found in three coves in the Summerset Bay area in Newberry County in late summer and fall of 2016.
With the assistance of the S.C. Department of Natural Resources, Lake Management began working to remedy the situation with an integrated plant management approach of herbicide and grass carp.
In November, 500 Triploid Grass Carp were released. Grass carp are a biological method offering unique advantages for management of hydrilla and other aquatic weeds, such as the longevity of the method with the fish’s constant feeding activity against the growing weed and lower long-term costs.
The use of herbicides to remove most the biomass of hydrilla before stocking with grass carp reduces the number of fish required, since the fish need to consume only the newly emerging hydrilla growth. This integrated approach appears to be an efficient and cost-effective way to manage hydrilla.
Hydrilla Verticillata, also called water thyme, is known to be an aggressive and competitive plant. It crowds out natural species and impedes irrigation and boating. It also degrades water quality, reduces property values, and increases habitats for mosquitoes.
Davis noted that water samples, collected in the affected coves, showed higher levels of Nitrogen than other areas around the lake. Nutrients such as Nitrogen and Phosphorus act as fertilizer for aquatic invasive species. Nutrients such as nitrogen can come from excessive fertilizers applied on dry land which then runs off into the lake.
The last major outbreak of hydrilla in Lake Greenwood was in 2006 through 2009. In 2009 and 2010, Greenwood County took a proactive approach with the release of Triploid Grass Carp. Since that time, the hydrilla has been kept at bay until this past fall when it was found on the Newberry County side of the lake.
Preserving Lake Greenwood serves Laurens, Greenwood, and Newberry counties by preserving and restoring the quality of Lake Greenwood for current and future generations through education and advocacy. Monthly meetings are held the third Thursday of each month at 1:30 p.m. at the Commission of Public Works, 121 W. Court Ave. in Greenwood.
Visit www.preservinglakegreenwood.org for more information. Greenwood Lake Management can be reached at 864-943-2648 or 864-942-8560.