Nov/Dec 2013Earth and Water, Wind and Sun
Battling Waterborne Pestsby David Lucas

The Land, Water and Conservation Division's Aquatic Nuisance Species program works statewide to prevent and control a variety of aquatic nuisance species, including hydrilla and water hyacinth. These non-native species can affect a variety of water uses, including public water supplies, power generation, and recreational activities like boating, fishing and hunting. Program staff can and will offer technical assistance to private landowners about how to manage invasive species in their ponds or small lakes, but by law, their efforts at removing or controlling invasive weeds like hydrilla, water hyacinth and other destructive invaders must provide a public benefit.

"We deal with aquatic invasive species on public water bodies," says Program Manager Chris Page. A few times each year, an acute situation will arise that requires what is basically an emergency treatment, but for the most part, the work that the Section staff carries out is carefully planned on an annual basis by the S.C. Aquatic Plant Management Council, a group consisting of representatives from ten different agencies including DNR, SCDHEC, Clemson University, Santee Cooper and others. Each year the Council devises a plan for aquatic pest control that is made available for public comment. Spraying with EPA-registered herbicides is by far the most common control method for invasive weeds, but according to Page, the program can also employ integrated pest management strategies that utilize a combination of physical control, herbicides and biological control methods. The latter method enlists the aid of other organisms in the fight against aquatic invasives. For example, sterile grass carp that eat hydrilla and other weeds can be stocked in problem areas, and the tiny alligatorweed flea beetle is also used to combat that noxious plant. In recent years, clearing invasive weeds from several public drinking water sources has been a major focus for the section.

"We have long-standing issues at several important reservoirs around the state," says Page.

For instance, the Goose Creek and Back River reservoirs provide drinking water for the Charleston metropolitan area. Keeping the water in those systems free of noxious weeds that restrict flow and degrade water quality is very important to the residents of that region, many of whom have no idea that they owe much of both their continued access to public waters for recreation, and the availability of their drinking water, to the work performed by one small but hard-working section of the DNR's LW&C Division.