The Pearl River Valley Water Supply District (PRVWSD) is taking steps to eradicate giant Salvinia in the Ross Barnett Reservoir. This is the second time the plant has been found in the reservoir.
Giant Salvinia is an aggressive non-native aquatic plant that was found in the Pelahatchie Bay area.
PRVWSD and Mississippi Department of Wildlife, Fisheries and Parks (MDWFP) officials have said the plant is introduced to new waters primarily by boaters.
They said it is important that all boaters clean, drain and dry all boating equipment after each use to limit the spread of invasive species.
Bobby Cleveland, with PRVWSD, said the most common way of spreading aquatic vegetation is by boaters. In this instance, they believe the giant Salvinia was introduced by a fisherman, due to the area where the vegetation was found.
A few small plants have been found throughout a five-acre area in the reservoir.
“A trolling motor or gas motor or any rails that are exposed, they could all transplant part of a plant that can re-root and start growing again,” Cleveland said. “It can be flushed out of a livewell system as well.”
Cleveland encourages boaters and fishermen to inspect the outside of their boats and trailers.
“It can sometimes be caught between the trailer and the boat,” he said. “There are a lot of catch points on a trailer where vegetation can get stuck. Remove any plants that you see. Wash it with soap and warm water. That’s probably the most effective.”
Cleveland said all water should be drained from the boat before one even leaves the lake that they’re fishing.
“There are a hundred different places it could get caught,” he said. “Only one small piece of a plant could spread. And when you’re inspecting your boat, don’t do just a simple walkaround. You have to take a bit of time to look.”
MDWFP officials have said that efforts to rid the Reservoir of giant Salvinia will include multiple applications of several herbicides.
An aggressive spraying campaign by MDWFP will soon be underway.
“This is a plant where in a matter of five or six weeks’ time it completely took over many acres of a lake it was in,” Cleveland said of some research he has done on the vegetation. “It can get so bad that if a fish swam up on it, it would die. That’s how thick this stuff can get.”
Cleveland said they are using caution to keep their spraying in those small areas where giant Salvinia has been found in the reservoir to avoid killing the natural vegetation.
Unfortunately, MDWFP said these herbicides could have a negative impact on important native vegetation, including lily pads.
“There will be some loss of native grasses, but it is not a massive spraying effort,” he said. “They have done a great job of isolating it.”
The first time the plant was found in the Reservoir in 2013, a biologist saw a small patch in the harbor at the Goshen Springs boat ramp on Highway 43.
It was quickly eradicated and removed from the water.
Giant Salvinia in the Reservoir was first found by MDWFP in a small patch along the Pelahatchie Bay’s north shore earlier in the summer. However, it has spread in small patches across a five-acre area since then.
According to a release from PRVWSD, Giant Salvinia is an aquatic fern native to Brazil.
Biologists with MDWFP have said it is one of the country’s most dreaded, invasive plants because of its rapid growth potential and the difficulty of eradication.
The plant is capable of doubling its biomass in 36 hours in optimal conditions, such as warm, still waters.
If the plant is not eradicated, it could take over in a matter of weeks with mats up to three feet thick, choking out all aquatic life and could make boating, swimming or fishing impossible in affected areas.