Whirling disease has been found in Western Maryland

Whirling disease has been found in western Maryland streams. Here is some information about whirling disease and what you can do to help control the spread of this disease. For more information you should contact the Maryland Department of Natural Resources. Contact: customerservice@dnr.state.md.us Web Page: http://www.dnr.state.md.us/fisheries/#3 Or the Whirling Disease Initiative http://whirlingdisease.montana.edu/ What is Whirling Disease?

Myxobolus cerebralis (Mc) is a parasite that infiltrates the head and spinal cartilage of fingerling trout where it multiplies rapidly, putting pressure on the organ of equilibrium. This causes the fish to swim erratically (whirl), and have difficulty feeding and avoiding predators, in severe cases, die. In severe infections, the disease can cause high rates of mortality in young-of-the-year fish. When an infected fish dies, millions of tiny indestructible Mc spores (each about the size of a red blood cell) are released to the water where they can survive in this “dormant” form for up to 30 years.

Therein lies the gravity of the whirling disease problem. M. cerebralis is virtually indestructible — the spore can withstand freezing and desiccation, and can survive in a stream for 20 to 30 years. Whirling disease is most infective to rainbow and cutthroat trout, but can infect all salmonid species, including brook trout.

Is there anything anglers and boaters can do to help prevent further spread?

Anglers, boaters, and others can make a difference in reducing the chances of spreading whirling disease. Distribution of the parasite is expanding rapidly in some areas, so you should assume its presence if you don’t know otherwise. Recommended precautions that will help prevent not only the spread of whirling disease, but also other disease-causing organisms and aquatic pests include:

  • Never transport live fish from one water body to another. (This is illegal in many states.)
  • Dispose of fish entrails and skeletal parts properly. Never discard fish parts in or near streams or rivers. Do not discard fish parts in a kitchen disposal. Whirling disease myxospores can survive most wastewater treatment systems. Instead, discard in dry waste that would go to a landfill.
  • Contact the Department of Natural Resources at 800-688-3467 if you observe signs of whirling disease in fish or observe illegal stocking.
  • Obtain certified disease free fish for any private stock projects.
  • Rinse all mud and debris from equipment and wading gear, and drain water from boats before leaving an infected drainage. This is good practice for preventing transfer of other aquatic hitchhikers as well.
  • Although the above precautions will remove most spores from your gear, you may want to consider the following if fishing in heavily infected waters: Rinse, then thoroughly dry your boots, waders and other fishing equipment. This is generally sufficient to kill the TAM stage of the parasite. For disinfection options if your equipment does not have time to dry thoroughly.

Reprinted with Permission of the Whirling Disease Initiative Whirling Disease Initiative

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