As spring shifts into top gear, boat dock-choking aquatic plants such as hydrilla and watermilfoil start becoming abundant in Tennessee River reservoirs.
A Guntersville, Ala.-based aquatic weed management company is researching products and techniques to control the invasive plants and, in a separate development in the battle against water weeds, has recently been licensed by the Environmental Protection Agency to use a promising new product, company officials said in a recent statement.
According to the U.S. Environmental Protection Agency data on SePRO Corporation’s ProcellaCOR, two versions of the product were issued EPA registration numbers on Feb. 27. The version Aqua Services Inc. is now licensed to apply treatments to problem plants such as those most common on the Tennessee River, while the other version is aimed at controlling aquatic weeds in rice production settings. The active ingredient in the herbicide is florpyrauxifen-benzyl and the substance makes up 26.5 percent of the product, according to EPA records. Registration by the EPA is not an endorsement or recommendation of the product.
The new herbicide, SePRO Corp.'s ProcellaCOR, "provides a new mode of action when compared to other aquatic herbicides. It is a systemic herbicide that is used at very low rates, requires very short contact times and destroys milfoil and hydrilla colonies for the entire season," Aqua Services Inc. officials said in a statement released on Thursday.
ProcellaCOR "has a high degree of safety with regards to health, human safety and the environment," said Aqua Services vice president and managing partner Troy Goldsby.
"This is best demonstrated by the fact that there are no restrictions on drinking water, and you may swim, fish and irrigate turf immediately in areas where it has been used," he said. "... In some areas, it will alleviate many of the major problems and complaints that we hear from fishermen, boaters, and lake property owners."
Aquatic weed control rarely finds fans among anglers who fish for trophy-sized, largemouth bass on the Tennessee River and they like vegetation — even non-native plants — because it serves as habitat and cover for their quarry, the Times Free Press reported in September. Conversely, lakefront property owners' docks can become surrounded by vegetation so thick even boats without motors mire up in the mess.
Chattanooga Bass Association vice president Brad Ferguson said the issue is "a touchy situation."
Ferguson on Thursday said he agrees water weeds are a problem for dock owners but there are other problems on the Tennessee River that go unnoticed, like shoreline erosion and the invasive non-native aquatic animals.
Erosion damages property and habitat, and the Tennessee Wildlife Resources Agency says Zebra mussels can spread rapidly and compete for food eaten by native larval fish and other animals.
Lakefront property owners "despise aquatic vegetation because it takes water away from them that is accessible," Ferguson said.
Ferguson likes to fish near docks with lots of vegetation, but he admits he'd want less of it if it was his own dock. The key is finding a middle ground.
"Control is one thing, eradication is another," he said.
Two of the biggest weed offenders, hydrilla and Eurasian watermilfoil, came from non-native sources, state and federal officials have said over the years as the region's water weed war waxed and waned.
Drought promotes aquatic weed growth because water flow rates decline and fewer plants are washed away by current. Likewise, seasons with heavy rain often see a decline in aquatic vegetation, officials said.
According to TVA and state Department of Environment and Conservation officials, hydrilla first was used in Florida as an aquarium plant, and it probably made its way here on the boats and trailers of vacationers and fishermen.
According to TDEC and TVA officials, hydrilla first was documented in Chickamauga Lake in the late 1980s. A spring flood in 1988 pulled up most of it, sending it to the deep, dark water at the base of Chickamauga Dam, officials said. Hydrilla almost vanished from Chickamauga Lake after that.
But it started making a comeback on Chickamauga back in 2011, and often comes and goes elsewhere, the Times Free Press has reported.
Meanwhile, Eurasian watermilfoil probably was introduced from a small pond on Watts Bar Lake in the 1960s, then spread downstream from Watts Bar over the years, officials said.
Aqua Services officials hope new techniques and products can improve the situation.
The company this year entered into several cooperative research agreements to investigate control techniques and products for the management of problem weeds, according to Terry Goldsby, company founder and senior botanist. The company has satellite offices in Tennessee in Chattanooga, Franklin and Counce.
In its research effort, Aqua Services began looking for test sites in early February so research on products and techniques to control problem weeds can begin before water levels on Chickamauga, Watts Bar and Fort Loudon reservoirs are raised to recreational levels for the season, according to Terry Goldsby.
"[H]undreds of acres of aquatic weeds are impacting near-shore zones within many areas of Chickamauga, Watts Bar and Fort Loudon reservoirs," he said in a statement. "[D]ue to the fact that the water level in these reservoirs is lowered each winter and early spring, there is a real opportunity to treat exposed bottoms with EPA-approved aquatic herbicides prior to reflooding these areas."
Using specific techniques and products, the company "may find that pre-emergent treatments present us with a 'best management practice' that allows us to lower herbicide rates while achieving persistent, sustained aquatic weed control," Terry Goldsby said. "It is important to look closely at new techniques and products so we may make the most environmentally conscious decisions with regards to aquatic plant management."
Terry Goldsby said the company is actively searching for test sites.
Contact staff writer Ben Benton at email@example.com or 423-757-6569. Follow him on Twitter @BenBenton or at www.facebook.com/benbenton1.