Santee Cooper will conduct aerial treatments through Aug. 7 to control invasive plants in Lake Marion.
The treatments use Environmental Protection Agency-approved aquatic herbicides, targeting primarily crested floating heart, an invasive aquatic plant found in upper Lake Marion.
These applications should improve lake access for residential and commercial properties, restore recreational opportunities and help prevent the spread of these plants to other areas within the Santee Cooper lakes.
Santee Cooper first discovered crested floating heart about a decade ago, when the weed was mistaken for a small colony of big floating heart in the Eutaw Creek area of Lake Marion near Eutawville.
Both crested floating heart and big floating heart belong to a genus of aquatic flowering plants known as nymphoides. Big floating heart is native to the Santee Cooper lakes and provides a good habitat for fish and waterfowl, whereas crested floating heart originates from Asia and chokes out other aquatic plants.
Distinguishing it from big floating heart can be difficult, but reining it in is even more difficult.
Santee Cooper has been targeting crested floating heart with herbicidal treatments since 2005 but has had limited success. It's the most aggressive floating-leaf plant the agency and the state Department of Natural Resources has encountered in the lakes and can grow in active areas in depths up to 12 feet. Most Nymphoides thrive in shallow backwater areas.
It also has demonstrated an ability to spread upstream against the predominant wind directions and flow pattern of the lakes, which is likely caused by its tendency to attach to boat hulls.
The Santee Cooper Lakes consist of approximately 160,000 surface acres, and crested floating heart has the potential to cover as much as 40 percent of it. It currently occupies about 5,200 acres.
Crested floating heart so far has been primarily contained to the Santee Cooper lakes, but the S.C. Department of Natural Resources recognizes it as a potential threat to all South Carolina waterways. Its resistance to herbicidal treatment combined with its aggressive growth makes it a serious menace to any aquatic ecosystem. Perhaps the biggest threat posed by crested floating heart is its ability to create a monoculture, or single-species habitat. It can outcompete and dominate other species and cause total changes to an ecosystem.
Santee Cooper has been working with SCDNR since 2005 to get crested floating heart designated as an official aquatic nuisance species in South Carolina. This would make it illegal to sell or own and could possibly secure additional resources to combat it.
In the meantime, Santee Cooper continues to employ herbicidal treatments and a public awareness campaign. Boaters are encouraged to check their boats and trailers to make sure they aren't inadvertently transporting crested floating heart from one area of the lakes to another.
If you spot crested floating heart in the Santee Cooper Lakes or in any South Carolina public waters report it to SCDNR at invasiveweeds@dnr.sc.gov or by calling (803) 755-2872. Please also report it to Santee Cooper by calling (843) 761-4078.
