February 20, 2007


Depending on where you live, this may be the first time you’ve ever heard of the fish pathogen viral hemorrhagic septicemia, or, VHS. Chances are, however, that this will not be your last. VHS is caused by a rhabdovirus designated as the viral hemorrhagic septicemia virus. Some fish affected with VHS will show no external signs, while others show signs that include bulging eyes, bloated abdomens, inactive or overactive behavior, and hemorrhaging in the eyes, skin, gills, and at the base of the fins. Infected fish may also have lesions that look like those caused by other fish diseases. Acute signs are typically accompanied by a rapid onset of mortality. This disease transmits easily between fish of all ages, and mortality is highest at low water temperatures between 37 and 54 degrees Fahrenheit. The media hasn’t yet caught on to what VHS is potentially capable of in North American waters. Unlike most fish pathogens, VHS kills healthy fish. VHS found in the Great Lakes has evolved from the European strain, which affected cold water fish like salmon, and now has been documented to affect most types of fish in North America (cold, cool, and warm water).
This is going to be a HUGE issue, and it will affect almost everything a fisherman/boater does. The Federal government has already shut down the transport of fish across state lines in much of the northeast and great lakes region with a Federal Order. This affects not only fish stocking and management by government and tribal agencies, but also the aquaculture and the bait industries. Effects of the transport ban in the region will include the availability and cost of shiners and other minnows at bait shops, trout, salmon and sturgeon management and reintroduction, in addition to issues like the debate about whether or not to stock Leech Lake strain muskies in WI, likely falling by the wayside.
This is a very disturbing issue that MN DNR Fisheries is addressing, and along with other invasive species management, will unfortunately take dollars away from actual fish management. 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 by thoroughly cleaning boats, trailers, nets, and other equipment when traveling between different lakes and streams. The use of a light disinfectant such as a solution of one part chlorine bleach to 10 parts water (i.e., 1 gallon of bleach to 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 for 30 minutes is also an effective method to prevent the spread of a wide range of aquatic nuisance species.
I believe the only way we will be able to fight this thing (and other invasive species) is to begin with our own actions. We, as citizens need to make it known that we will not stand for industry dictating how they will treat ballast water, i.e. not treating it. We need to tell them stop. I encourage you to write or call your legislators. Then, do your part and support your actions by decontaminating your boats, live-wells, and gear, and prevent the spread of invasive species.
Let’s let our actions speak for themselves. As a wise man once said, “if you aren’t willing to fight for something, it ain’t worth having”. Let’s all do our part to fight the spread of invasive species in Minnesota.