Killer Fish Disease

Discussion in 'The Lounge' started by Buick Riviera, Jul 2, 2008.

  1. Buick Riviera

    Buick Riviera Willows and bass go together like beer and pizza.

    According to our local paper, the Division of Wildlife has confirmed on outbreak of viral hemorrhagic septicemia disease in fish in Clear Fork. This is the first lake in the United States to test positive for this disease.

    It is a killer of fish but is not transferable to humans according to the ODW. I'll try to find a link to the story.

  2. No, it is not the first lake in the US to test positive.
    Been in the US since 98, been around since the 30's in Europe. Many fish kills in the US. I personally feel that it's more widespread then one thinks and time will prove this.

  3. crittergitter

    crittergitter Multi Species Angler

  4. Buick Riviera

    Buick Riviera Willows and bass go together like beer and pizza.

  5. In case any of you aren't reading the muskie forum, here's something I posted there:

    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. ...And where Clear Fork is a legit first, the detection of VHS there is the first inland in North America off the Great Lakes watershed, i.e., the first on the Mississippi watershed. All other cases in the US have been on the marine coasts or within the Great Lakes watershed.
  7. Finally...where you been all my bass life!

    Rational scientific da man!!!

    Please tell me this one-

    The new formulation of Catch and Release (SureLife Labs) reports removal of pathogens INCLUDING VHS.

    We have been using this product since it's first intro last summer, especially with the nearby great lakes concerns and our moving from lake to lake with weigh-in equipment.

    Do you have any info about this products effectiveness with reducing the liklihood of transmitting pathogens, not just in the water, but also fish to fish.


  8. I dug around the Sure-Life site for a bit, but couldn't find anything to tell me what is actually in "Catch and Release." They're really big on offering lots of claims, but I'm skeptical of anybody who comes to me selling a panacea, especially when they aren't interested in telling me what active ingredients their panacea contains (and they misspelled "quagga" as "quassa"!). Also, killing multi-celled aquatic organisms (like dreissenid mussels) and reducing stress in others (like fish) are very different intents; the ingredients to do each may detract from the effectiveness of the other (again, I can't know without knowing what this stuff is). Myself, I'd rather buy stress reducers and biotic purging agents separately. I suspect their formula may be an effective stress reducer and may even be harsh on viral pathogens outside a host, but so are many. I will say that when culture facilities treat eggs to try to prevent the transmission of VHS, it's with good old-fashioned iodine.

    VHS is a virus, which means it's a simple bundle of genetic material and not a living cell like those that make up you, me, fish, bacteria, etc. Computer viruses are aptly named because they are also only code; biotic viruses are a bit like biological "software" or "malware." When a biotic virus attacks, its genetic material is incorporated into and replicated by its host's cells. Most viruses do not persist very well outside of a host and, once incorporated into a host, cannot be easily removed until a host's own immune response begins to block the attachment of a virus to its cells (via antibodies). That is, in spite of the popular press batting the term "cure" around, you don't ordinarily "cure" any viral infection.

    So, do not treat any living fish with any over-the-counter product and believe it has been purged of any viral infection. The notion that the angling public should NEVER move a live fish from one body of water to another remains, no matter what your livewell treatment is.

    One issue with type IVb VHSv--which is the strain of the virus that invaded the interior of North America--is that it is new enough that not a lot of epidemiology has been done with it in freshwater yet. There is some brand new stuff coming out of the Canadian Dept. of Fisheries & Oceans lab on Vancouver Island that suggests type IVb can persist as an infectious agent for a great long time in cold, clean freshwater. Start increasing temperature, adding bacteria, various ions, etc. and type IVb is pretty fragile outside a host. That said, whatever is in "Catch and Release" may be pretty harsh on VHSv in the water, outside host fish. How quickly it would eliminate the infectivity of the virus would probably depend upon several external variables, especially temperature. ...But again, who could say with certainty without knowing what "Catch and Release" actually is?

    Type IVb VHSv is ordinarily considered a "low mortality" strain. It really appears to need a certain set of conditions to go from an illness to a killer. All the VHS strains are coolwater and do not function in warm. Some work out of Case Western Reserve U. suggests that a prolonged cool spring may be a trigger that allows the virus to stay active before fish immune response is fully "geared up" for the coming season.

    Sorry to go on so long and I hope some of this is at least interesting. If you have questions regarding how these issues relate to Lake Erie specifically, I am also a moderator on this board (which tends to be a little more science-/general interest-based and a little less angler specific):