ODNR press release concerning VHS

Discussion in 'Muskie & Pike Discussions' started by Weatherby, Jun 18, 2008.

  1. News Release


    June 17, 2008


    COLUMBUS, OH - The Ohio Department of Natural Resources (ODNR) has confirmed that viral hemorrhagic septicemia (VHSv), a virus that causes disease in fish but does not pose any threat to public health, was confirmed present in muskellunge sampled during routine egg collection in Clear Fork Reservoir in late April. The reservoir is located in Richland and Morrow counties.

    The virus was found in ovarian fluid samples collected from the muskellunge as part of routine ODNR testing for VHSv, but has not resulted in a fish kill. The samples were sent to the U.S. Fish and Wildlife Service (USFWS) Fish Health Center in LaCrosse, Wisconsin, where the VHSv virus was initially isolated. It was later confirmed at the National Veterinary Services Laboratory, U.S. Department of Agriculture Animal Plant Health Inspection Service (APHIS) in Ames, Iowa.

    These results mark the first isolation of VHSv outside the Great Lakes Basin. Fisheries officials believe VHSv has been a factor in recent fish kills of several species of fish in the Great Lakes that correspond with the end of spring spawning.

    VHSv was first isolated as a virus in 1963, and is presumed responsible for European fish kills as far back as 1938. In 1988, the virus was first detected in marine fishes in the Pacific Northwest. VHSv is a pathogen of international concern and is reportable to the World Organization for Animal Health (OIE).

    In 2005, VHSv was first reported in the Great Lakes, but may have been responsible for fish kills since 2003. VHSv has been responsible for numerous fish kills in lakes Erie, Huron, Michigan and Ontario. The virus has also been the cause of fish mortality in several inland lakes in the states of Michigan, New York and Wisconsin - all within the Great Lakes Basin.

    As a result, APHIS issued an emergency order in 2006 restricting the interstate movement of live fish of susceptible species from the states and provinces of the Great Lakes. Many states around the Great Lakes, including Ohio, developed their own emergency orders restricting intrastate movement to protect other watersheds within their states. For a list of susceptible species, visit APHIS's Web site at http://www.aphis.usda.gov/.

    "One likely possibility is that VHS will act like many other viruses in the environment. Typically, viruses or bacteria infect fish, which may lead to disease in the fish if they are susceptible. Once the disease is expressed in these fish, some percentage of the population will die," said Ray Petering, chief of the DNR Fisheries Division. "Those remaining will survive and will develop immunity to the viruses or bacteria that cause a disease. Since there are no large-scale treatments for VHS that can be applied to fish in the wild, the presence of this new virus may result in spring fish mortalities that are abnormally high for a few years, as more fish encounter the virus. These mortalities may abate as fish begin to build immunity to the virus."

    Citizens are encouraged to report sick fish or fish kills by calling 1-800-WILDLIFE or use the ODNR Web site at: http://www.dnr.state.oh.us/default/tabid/6518/Default.aspx then from the topic list select: Wildlife - Fishing & Hunting.

    Anglers should contact the ODNR if they observe large numbers of fish exhibiting any of the following: hemorrhaging in the skin, including large red patches particularly on the sides and on the head; multiple hemorrhages on the liver, spleen, or intestines; or hemorrhages on the swim bladder that give the otherwise transparent organ a mottled appearance.

    This information will help ODNR track VHS and take appropriate actions to slow the spread of this virus. Anglers and boaters can help prevent the spread of VHS and other viruses or bacteria that cause disease in fish by not transferring fish between water bodies, and thoroughly cleaning boats, trailers, nets and other equipment when traveling between different lakes and streams.

    The use of a contact disinfectant such as a solution of 200 ppm chlorine bleach (5.1 ounces per 10 gallons of water) to clean vessels and live wells is very effective against VHS and other viruses and bacteria that cause disease in fish. Soaking exposed items such as live wells, nets, anchors and bait buckets in a light disinfectant of 20 ppm chlorine solution (5.1 ounces of liquid household bleach per 100 gallons of water) for 30 minutes is also an effective method to prevent the spread of a wide range of aquatic nuisance species.

    Routine surveillance, disinfection of eggs used in fish production, public education and additional VHS research will continue by the ODNR, Ohio Department of Agriculture and the U.S. Fish & Wildlife Service in an effort to minimize the spread of VHS and protect fish hatcheries.

    If anyone has questions please post them here so I can try to get answers.
  2. crittergitter

    crittergitter Multi Species Angler

    Thanks for posting the information Chris!



    Is it safe to assume this will not affect the stocking program, ie by collecting the eggs from the fish in CF this will not affect the fry and be transferred to other lakes when the fingerlings are stocked?

    Have they tested any fish from other musky lakes in Ohio?

    Will this affect the number of fingerlings stocked into CF this fall and for the next few years?


  3. There are two hatcheries currently raising muskie, London and Kincaid. The London hatchery has the Clearfork eggs, Kincaid hatchery has Salt Fork eggs. Of course the London eggs are under quaratine for further testing.

    We already collect eggs from Saltfork Lake and we have enough fingerlings at Kincaid to cover our Program needs.

    I believe they have all been tested.

    We have sampled the Clearfork fingerlings at London and OSU (both treated with Iodine) for VHS and should have those results in the next couple of weeks. The fry and fingerlings have both done well to date and shown no signs of any viral infection.
    As long as Clearfork fingerlings at London test clean and we can stock Clearfork with London fish. We will continue to stock Clearfork.
  4. crittergitter

    crittergitter Multi Species Angler

    Thanks for the info Chris. Nice work!

  5. A side note. Not only the ODNR monitors for VHS, but the Ohio Department of Agriculture (ODA) does as well in collaboration with the ODNR, my office, and the USFWS. I work for the Ohio Sea Grant College Program at OSU. In that capacity, I was contracted to sample fish from 22 inland sites around the state (i.e., upstream of the US-6/I-90 line) for ODA's VHS monitoring efforts. I collaborated with the USFWS field office in Reynoldsburg on the fish collections, and the cell culture/VHS testing was done by the ODA Animal Industry lab also in Reynoldsburg. Fish collections and testing procedures followed USDA protocols. I've been presenting those data here and there at various venues since autumn 2007.

    Totally coincidence, but we happened to be electrofishing Clear Fork the very same day this spring that the Division was trapnetting muskie there. Our Clear Fork catch of susceptible species was a mixed bag of centrarchids, brown bullhead, etc. and included no muskie. Cell cultures for our sample were all negative. Upon the positive test results from ovarian fluid of Clear Fork muskie, ODA went back and retested our samples using PCR technique. PCR is more sensitive than cell culture, but only detects the presence of the virus' genetic material: i.e., it can detect the presence of virus in an organism whether or not that virus is infectious and actively replicating (any virologists reading, please forgive this bit of simplification). All PCR tests on my catch were also negative.

    So, it appears VHS is only present in Clear Fork's muskie and has not moved to other populations in that reservoir's fish assemblage. It's commonly accepted that muskie are amongst the most susceptible to VHSv-induced symptoms. In spite, note that there have been no kills or even observed symptoms in Clear Fork's muskie. Like Ray and some others within the ODNR, I’m skeptical regarding a substantial long-term impact of VHS on large wild populations (like within the Great Lakes). A virus seldom causes 100% mortality, and exposed organisms that survive are often resistant; note there have been no confirmed sizable VHS-related kills on Ohio’s Lake Erie waters after spring 2006 (in spite of VHS-positive yellow perch collected by Case Western Reserve U. on Erie in both springs 2007 and 2008, still without any kills evident). I believe such diseases pose greater potential risk to smaller, man-made reservoirs and culture/capture operations, especially where fish can be crowded and/or stressed.

    So, don't be moving live fish, bilge water, bait, etc. from lake to lake out there, but also don't put any stock into the terrible "Ebola" hype of the popular press.
  6. crittergitter

    crittergitter Multi Species Angler

    Now there's some good information. Thank you Eugene. The subject also came up on RS.com due to the article in the dispatch. So, if you don't mind I'll paste this information there as well.

  7. Feel free, Mr. Gitter.