Whirling disease has been found in another of the state's fish hatcheries.
Early Tuesday, wildlife officials announced the Mammoth Creek Hatchery south of Panguitch tested positive for the fish-killing disease.
This is the second hatchery hit with the disease. Back in 2000, the Midway Hatchery west of Heber had to be closed and millions of fish killed. The Midway facility produced more than 20 percent of the state's planted fish. It could be several years before that hatchery is able to raise fish again.
"This one (Mammoth Creek) really caught us by surprise," said Joe Valentine, aquatic culture supervisor with the Utah Division of Wildlife Resources. "We're not sure where it came from. There are no contaminated waters anywhere around. It very well could have been brought in accidentally by a fisherman."
Of particular concern is the fact that nearly half of the hatchery's annual production of 60,000 pounds of fish, mainly rainbow and splake, already have been planted.
"Now we'll have to go back and test those waters. We may have planted contaminated fish before we realized we had the disease in the hatchery," Valentine said.
About 35,000 pounds of fish currently in the hatchery will have to be destroyed.
Some of the lakes planted with fish from Mammoth include Navajo, Duck Creek, Enterprise and Kolob.
The original test in May showed only one of the 60 fish tested had the disease. A follow-up test showed six of the 60 fish were positive. Those results were confirmed July 5.
The hatchery will be closed and is not expected to reopen for at least 18 months.
"It seems that with every gain we make, we encounter something like this that sets us back," said Valentine. "We're going down in overall production rather than up, and that hurts."
An emergency response team has been formed to develop an action plan to deal with the situation.
Whirling disease starts with a parasite. It is spread by small worms, called tubiflex, which eat the parasite, which in turn are eaten by fish. The parasite causes, among other things, a curving of the spine in fish, which causes them to swim in circles, or whirl.
In March 2000, whirling disease was found in the Middle Provo River between Jordanelle and Deer Creek. By April, parasite spores were found in the hatchery.
At first, biologists thought whirling disease spores were carried to the Midway ponds by birds or animals. Later, however, three springs that fed the hatchery were isolated, and sentinel fish were placed there for testing. Fish in two of the three springs eventually tested positive for the disease.
Disease-proofing the hatchery will cost millions. Rearing raceways, for example, will need to be built above ground to avoid contaminated groundwater. Also, the raceways will need to be enclosed in order to avoid contamination from birds or animals.
Whirling disease was first discovered in Utah in a private hatchery owned by the family of Gov. Mike Leavitt in Loa in 1991. Since that time, it has spread to many of Utah's most popular fishing waters, including the Logan and Weber rivers, Rockport, Deer Creek, Otter Creek, Minersville and Hyrum reservoirs.
Once it has been found in a natural river or reservoir, it is impossible to eliminate. The cost of simply trying to contain the disease here in Utah has run into the millions of dollars.
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