Whirling Disease Confirmed In Yellowstone NP Trout

[hatrack]

CHEYENNE, Wyo. - "A parasite that causes trout to swim in circles has prompted Yellowstone National Park to prohibit fishing in a drainage that empties into Yellowstone Lake.

The angling season for the Pelican Creek drainage, a 50-square-mile area on the north end of Yellowstone Lake, was scheduled to begin May 29. It is unknown when fishing might resume in the drainage, Chief Fisheries Biologist Todd Koel said Wednesday. Not that anglers would have much luck, anyway. Because of whirling disease, few fish are left in the creek.

For decades the U.S. Fish and Wildlife Service maintained a fish trap near the creek mouth and counted Yellowstone cutthroat trout that entered the stream from Yellowstone Lake to spawn. In the early 1980s, some 30,000 fish migrated into the stream each year. In August, 2002 — a time of year when the creek would be expected to be teeming with very young fish — researchers found no fry in the lower seven miles of the creek. Last August, they counted just nine fry. "They're just not there anymore," Koel said. "The fish are gone."

Whirling disease was first detected in Yellowstone in 1998. Park officials theorize that the whirling disease parasite, which is native to Europe and has been spreading across the United States since 1956, might have hitched a ride into the park on someone's fishing gear."

EDIT

[John Doe Freedom]

1. What organism causes this?

Is it viral, bacterial, protozoan, or worm? Can it be innoculated against? This is bad.

[hatrack]

2. Some sort of parasite - the article doesn't clarify just what.

Apparently the vector is an aquatic worm, but beyond that, I need to do some research.

[Redneck Socialist]

3. Myxobolus cerebralis

More info at the link below.

http://wildlife.state.co.us/Colo_Wild_Co/fall1996/Whirling_Disease%5B1%5D.htm

In short it is a parasite that can cause nerve damage, skeletal deformities and death to fish.

"It goes through a complex, two-stage life cycle in which fish are just one of the hosts (animals in which the parasite lives). In the first part of its life cycle, the parasite is released from the bodies of diseased fish in the form of very hardy spores which can withstand drought and freezing and survive for decades in streams. These spores then infect a common type of worm, called tubifex, which lives in the muddy bottoms of streams and rivers. In the worm, the spores grow rapidly, changing into an active form which can infect fish. Once the parasites are released by the worm, the invade the bodies of healthy fish through the skin, migrating parallel to the nerves to the cartilage. Spores can also be transmitted when a fish eats an infected worm. Birds and mammals which have eaten infected fish can spread the spores to unaffected waterways via their feces."