Trout Whirling Disease To Affect Spring Stockings

When it comes to potential disasters, it’s best to expect the worst and have a plan. That plan should include erring on the side of caution and getting help from your allies.

That way of thinking by WRD Chief of Fisheries Scott Robinson and his staff has salvaged the state’s 2022 trout stocking program.

Whirling disease, a parasitic disease that affects trout, has spread west and east across the U.S. since first being discovered in Pennsylvania in 1958. Now confirmed in more than 20 U.S. states, it was discovered in two Georgia trout hatcheries last year. That resulted in WRD destroying more than a half-million juvenile fish and fingerlings earmarked for stocking in Georgia trout streams.

Fortunately, the disease was caught early and it was not introduced to any trout streams in this state, Robinson said.

With fingerlings and eggs provided by the U.S. Fish and Wildlife Service, some neighboring states and some private hatcheries, WRD Fisheries is currently rebuilding its trout stocks and will resume restocking Georgia streams this spring. 

WRD missed some small, planned stockings of streams late last year, Robinson said, but those stockings were negligible.

Disaster averted.

The microscopic parasite that causes the disease infects a mud-dwelling worm commonly found in lakes and streams. The parasite multiplies within the worm and is eventually released into the water where it drifts until it comes into contact with a trout.

The disease damages the trout’s nerves and cartilage. It often results in an unusual swimming pattern that appears as if an infected trout is chasing its tail. Common signs are a black tail and deformities to the head or body.

The disease reached the southeastern U.S. several years ago, first affecting trout in Virginia and finally in North Carolina.

“We knew when it reached North Carolina five years ago it was only a matter of time before it showed up here,” Robinson said. “We were not terribly surprised.”

John Damer, a senior fisheries biologist at the Region 1 office in Acworth, said problems arose last August when routine tests showed that first the Buford hatchery, then the Summerville hatchery, might have a whirling disease outbreak.

‘We do tests where we take several trout and grind them together to make a pellet and that pellet is tested,” Damer said. “Just one of the pellets at the Buford Hatchery tested positive. We assumed then there was a good chance that the Summerville Hatchery may also be affected. We tested there and one pellet there tested positive for the disease. That’s all we could find. Just one pellet at both places. Fish at both hatcheries were tested again and the disease was documented in just one pellet at both places.

“We had to assume then that we had the disease in both places in some small way. In an abundance of caution, it was decided to euthanize the trout at both hatcheries and take the steps that were taken.

“With the discovery of whirling disease in nearby states over the last five to 10 years, whirling disease coming to Georgia wasn’t completely unexpected,” Damer said.

Joe DiPietro, an avid north Georgia trout fisherman from Blue Ridge, said he doesn’t know if the state really needed to kill off all of the trout in its two hatcheries, but that is a moot point now. He said the discovery of whirling disease in a put-and-take fishery like Georgia has will have minimal affect compared to states out West where wild fish populations were affected. He said the affects in Georgia could be noticeable, but it will by no means ruin the fishery.

“Places like Fannin County where people fish the public access points, people will probably assume that there are not any fish around,” he said. “But trout stocked previously will still be around. You’ll just have to look for them. Some people will probably assume it’s the end of the fishery, but what it will really mean is that it’s just a slow year.”

Damer said after the hatcheries and all equipment was completely sterilized, the hatcheries received eggs from Montana and Tennessee and a few fish from some private growers. He said some of those fish were fry and others were 5- to 7-inches long. He said the goal is to stock 10-inch trout, but that won’t be possible when the state resumes its typical March through Labor Day stocking. He said fishermen polled wanted to see the state resume its normal stocking times even if it was with smaller fish.

Robinson said there’s no real way to pinpoint how the disease made its way into the Summerville Trout Hatchery in Chattooga County and the Buford Trout Hatchery in Forsyth County. The Summerville hatchery typically produces about 600,000 rainbow trout fry each year, while the Buford hatchery produces about a half-million brown and rainbow trout.

Robinson says he suspects that birds were the culprit in bringing the parasite into Georgia.

“The parasite can move around on waders, fishing equipment and other ways, including birds,” he said. “I suspect we got it from birds. The parasite can actually be passed through a bird’s gut and dropped and survive.”

WRD experienced several strokes of good luck in having to take immediate action in stopping the spread of whirling disease. 

First, the Burton Trout Hatchery in Rabun County, which normally produces trout fingerlings for stocking in Georgia streams, was closed for renovation and was not affected by the disease.

Second, WRD personnel had worked closely with North Carolina fishery personnel five years ago when whirling disease was discovered there. Part of that work included establishing protocols for dealing with the disease. WRD had those procedures at its disposal when the disease was discovered.

Robinson said his department has not yet put a calculator to what the presence of whirling disease has cost his department.

“We’re following the disease protocols, and that has included the purchase of hot water pressure washers to sanitize all of our trucks between stockings and to sanitize all of our other equipment,” he said.

He said there been other expenses due to the whirling disease outbreak that his department wouldn’t normally have.