didymo found in CUmberland River

Frankfort, KY – The aquatic nuisance plant Didymosphenia geminata, commonly referred to as didymo, is now in the Cumberland River below Wolf Creek Dam.

“I found it at Rainbow Run,” said Dave Dreves, fisheries research biologist for the Kentucky Department of Fish and Wildlife Resources. “We’ve heard reports from all over the river.” Rainbow Run is approximately 12 miles downstream of Wolf Creek Dam.

Didymo is an algae that blankets the stream bottom with thick mats that resemble wet cotton. It has a rough fibrous structure that is scratchy to the touch, not slimy feeling like most native aquatic vegetation.

“It is going to be a nuisance for anglers,” Dreves said. “There is no feasible control for it. It fouls lures that come in contact with the bottom and it breaks loose and floats on the surface. It is something they’ll have to deal with when they fish.”

Didymo is native to Canada and prefers cool, low fertility waters like a tailwater, but is aggressively expanding its range. Recent findings by the Environmental Protection Agency show didymo is also growing more tolerant of waters that are more fertile and at lower latitudes.

The noxious plant is now present in tailwaters in Tennessee and Arkansas and throughout the northern Rockies and Pacific Northwest. It is also now throughout Europe, Asia and even New Zealand. Didymo smothers native insects that trout and other fish eat and out-competes native plants.

“It would be beneficial for those leaving the Cumberland River below Wolf Creek Dam to check your felt-soled waders or boots, float boats, canoes, kayaks, motorized boats, boat trailers, bilge water and livewell for the presence of didymo,” Dreves explained. “If you find it, remove it at the river. Don’t take it home. We don’t want didymo to spread.”

The nuisance algae can survive several days out of the water in a moist environment such as in the felt of a pair of wade boots or waders or in the livewell or hull of a boat.

Anglers who recently fished Cumberland River below Wolf Creek Dam should soak equipment and clothing in a 2 percent bleach solution or a 5 percent solution of salt or dishwashing detergent. The surfaces must come in contact with the cleaning solution for a full minute and dry completely before using again.

If the cleaning solution isn’t practical, allow the affected equipment to dry for 48 hours before use. “All it takes is a single cell of didymo to infect a waterway,” Dreves said.

Aquatic nuisance species are exotic plants and animal species that cause adverse impacts to native species. These species are a national problem that can quickly spread and impact Kentucky waterways.

Other common examples of aquatic nuisance species present in Kentucky include the zebra mussel, silver and big head carp and the plant Phragmites – an invader of our limited wetland habitat.

There are state and national efforts to prevent, control and eradicate these nuisance species. Regrettably, once these species are established in an area, they become almost impossible to eradicate. The focus remains on prevention and control of their spread to other areas.