When a routine sample of Kokanee salmon was taken by the Utah Department of Wildlife Resources in northeastern Utah's Strawberry Reservoir in December, the results were an unwelcome surprise. Whirling disease, the cause of fish decline and hatchery closures throughout Utah in the past decade was found in some of the fish.

According to Roger Wilson, chief of the DWR's aquatic division, two of the 60 salmon that were captured tested positive for the disease. Wildlife managers were surprised the disease had entered the reservoir, something they had worked for years to avoid, but are optimistic about the future of the fish in the area.

"We have been worried about this for a while and are thankful that we haven't seen the disease in this lake before," Wilson said. "We tried to take every measure to prevent it, but we think the parasite that carries the disease got over the fish barriers near the west fork of the Duchesne River or could have been carried to the reservoir by humans or birds."

The DWR does not expect the disease to harm a large number of fish in Strawberry reservoir or for fisherman to see a difference in the spring.

Whirling disease usually only affects smaller fish whose bones have not hardened. The disease causes cartilage damage, cranial deformity and the fish to swim in a circular pattern.

"The biggest concern we have with the disease entering Strawberry reservoir is that the natural reproduction of the fish like the Kokanee, Brown trout and Rainbow trout will be affected," said Wilson.


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"We do stock the reservoir with all of those fish though, so if are plan is to either stock it with more fish to counteract the effect the disease has on natural reproduction. Or to begin stocking it with bigger fish who are less susceptible to the disease."

Wilson added that the DWR has also begun experimenting with Whirling disease resistant strains, like the Harrison- Hofer rainbow trout. While stocking the reservoir with more fish will cost the DWR more money, Wilson said it is worth it to ensure Strawberry reservoir remains a fishing mecca.

"Anglers do not need to worry about the disease ruining fishing in the area, it has hit other reservoirs and we now know how to control it and counteract its affect," he said.

Trevor Howard, a fly-fishing guide with Trout Bum 2 said he is not too concerned about the disease's impact on local fishing.

"A lot of places around Park City do not have a problem with the disease and I know it used to cause a lot of problems, but I don't think it does anymore," he said. "They took care of the areas that were really struck by it. If Whirling disease took over all of Strawberry reservoir, then it would affect our business. But I went up and fished there a few times over the summer and never caught a fish that appeared to have the disease."

Wilson said it is important to remember that Whirling disease does not impact humans and that history has shown there is life after Whirling disease for Utah's lakes.

Editor's note: This article has been corrected to reflect the proper name of the strain of whirling disease resistant trout.