|
Whirling disease, which is caused by a parasite known as Myxobolus cerebralis follows a vicious cycle. The parasite usually attacks younger fish, damaging the soft spine cartilage and causing severe deformities. The nervous system of affected fish becomes impaired and the fish, when startled, circles in a whirling motion, becomes susceptible to predators, and is unable to feed properly.
Although Rainbow Trout seem to be the most susceptible, salmon and most other varieties of trout are also reported to suffer from the disease. All infected fish do not die from Whirling Disease. Older fish, whose bone structure is already hardened, may get the disease, but the deformities found in the younger fish do not usually develop in mature fish. Humans are not affected by the disease.
What Causes Whirling Disease?
An aquatic worm, the Tubifex, feeds on dead, infected fish. Inside the worm, the spore of the parasite changes and becomes able to infect healthy fish. It is extremely powerful and can infect fish when released by the worm, or when a fish feeds on the worm. It can attack through the fish’s digestive system, or even through its skin. The cycle, once begun, repeats itself again and again until the trout population of a whole river system is affected. When one infected trout dies, hundreds of thousands of the spores are released, resulting in the possibility of hundreds of thousands more fish being infected. The spores are not affected by freezing weather and have been known to survive for 20-30 years. Fish-eating birds are also suspected to spread the disease.
How Widespread Is Whirling Disease?
Whirling Disease has been around for more than a hundred years. It was first discovered in Europe in 1893, but migrated to the United States, possibly through shipments of processed fish, in the 1950’s and has increased rapidly since that time. Rivers with wild Rainbow Trout populations of several thousand fish per mile have been reduced, in some areas, to fifty or one hundred fish per mile. At least 22 states have reported cases of whirling disease in their local waters, but it is likely that many other states’ rivers have undocumented cases of the disease.
What Is Being Done To Combat Whirling Disease?
Every year, the Whirling Disease Foundation works with other fish and wildlife groups gather to share the latest research and scientific advances concerning the disease. More resistant trout are being bred, and stronger efforts to avoid contamination of disease free waters are being made. More than 200 scientists from many agencies are researching the problem. However, government funding for the study of Whirling Disease has recently been severely reduced, so, if you are concerned that your favorite fishing hole may be affected, you may want to make your concerns known to your own local representatives, as well as to the current administration in Washington, D. C.
What YOU Can Do To Combat Whirling Disease
No one wants to see the trout and salmon population of the United States drop even more drastically than it has in the past few years. Some suggestions made by the Whirling Disease Foundation are:
1. Never transport live fish or body parts of fish from one body of water to another.
2. When fishing in waters known to be contaminated, rinse all mud and debris from boats, trailers, boots, etc., before leaving the area.
3. Demand that state hatcheries test fish for Whirling Disease before releasing them into uncontaminated bodies of water.
4. Learn all you can about the disease and inform others.
5. Encourage government agencies to fund more research on the subject.
6. Make a donation to the Whirling Disease Foundation so that they can continue working to save our trout and salmon.
| 
