In 2005, a new fish disease known as Viral Hemorrhagic Septicemia (VHS) was discovered in Lake Ontario, after a fish kill involving thousands of freshwater drum, round goby, and muskies. In just two short years between the spring of 2005 and the fall of 2007, the VHS virus spread rapidly to the St. Lawrence River, Lake Erie, the Niagara River, Lake St. Clair, the Detroit River, Lake Huron, and Lake Michigan. It has also spread to several inland waters (waters without any direct connection to the Great Lakes) in Wisconsin, Michigan, and New York. Dozens of fish mortality events have now occurred in these areas resulting in the deaths of tens of thousands of fish. Unfortunately, there is no vaccination or cure for the disease, thus it cannot be controlled - only contained. Containing the spread of this deadly fish virus and preventing it from entering Vermont will require restrictions on the movement of live fish and water, and fish testing and surveillance programs.
Viral hemorrhagic septicemia (VHS) is a deadly fish virus that is considered to be one of the most serious diseases of trout and salmon in freshwater environments in Europe. Outbreaks of the VHS virus can result in severe fish mortality events in commercial aquaculture practices as well as in wild populations, and can often have serious socio-economic consequences. For these reasons, VHS is listed as a reportable disease by the World Organization for Animal Health (OIE).
Scientists are not sure how the virus arrived in the Great Lakes. Like many Aquatic Invasive Species, it may have been introduced through infected fish or water dumped from the ballast tanks of ships from Europe. It may have arrived through infected fish migrating from the Atlantic Coast.
It has been determined that the strain of VHS now found in the Great Lakes region is most similar to that previously isolated from the Atlantic coast of North America, but it has been categorized as a unique strain of the virus. It is possible this is a mutated form of the Atlantic Ocean isolate.
Where is VHS currently found?
From the time it was first discovered in Lake Ontario in 2005, the VHS virus has spread rapidly to other Great Lakes waters. It is now found in the St. Lawrence River, Lake Erie, the Niagara River, Lake St. Clair, the Detroit River, Lake Huron, and Lake Michigan. It has also spread to several inland waters (waters without any direct connection to the Great Lakes) including Lake Butte des Morts and Lake Winnebago in Wisconsin, Budd Lake in Michigan, and several lakes and rivers in the Finger Lakes region of New York.
The most probable way the virus moved through fish populations in the Great Lakes is through natural movement of infected fish. The virus most likely spread from the Great Lakes to inland waters through the capture and movement of live fish such as baitfish, and the transfer of contaminated water from one waterbody to another.
Although VHS has not yet been discovered in Vermont, the chance of it being spread here through live fish and overland boat movement is very real!
VHS is not a threat to people who handle or eat infected fish. However, it does pose a real threat to the many species of Vermont fish it can kill. This virus is unique in that it is the first fish virus known to affect so many different fish species.
There are 37 fish species known to be susceptible to the VHS virus, 26 of which are found in the Great Lakes. There are 22 species in Vermont that are susceptible to this fish disease...
Black crappie Pomoxis nigromaculatus*
Bluegill Lepomis macrochirus*
Bluntnose minnow Pimephales notatus*
Brown bullhead Ictalurus nebulosus*
Brown trout Salmo trutta*
Burbot Lota lota*
Channel catfish Ictalurus punctatus*
Chinook salmon Oncorhynchus tshawytscha
Coho salmon Oncorhynchus kisutch
Emerald shiner Notropis atherinoides*
Freshwater drum Aplodinotus grunniens*
Gizzard shad Dorosoma cepedianum*
Largemouth bass Micropterus salmoides*
Muskellunge Esox masquinongy*
Northern pike Esox lucius*
Pumpkinseed Lepomis gibbosus*
Rainbow trout Oncorhynchus mykiss*
Redhorse sucker Moxostoma spp*
Rock bass Ambloplites rupestris*
Round goby Neogobius melanostomus
Smallmouth bass Micropterus dolomieu*
Walleye Sander vitreus*
White bass Morone chrysops
White perch Morone americana*
Whitefish Coregonus spp*
Yellow perch Perca flavescens*
* = Species known to occur in Vermont
The VHS virus is readily transmissible to fish of all ages, and survivors of infection can become lifelong carriers. The virus is shed from infected fish in urine, feces, and reproductive fluids, and transmission can occur through the water or by direct contact with infected fish, or contact with infected equipment.
The virus can persist in water in an infective state without a fish host for up to 14 days. It has also been documented that the virus is not always killed by freezing infected fish. In a hatchery or fish holding facility, transfer of the VHS virus on contaminated surfaces of gear and equipment presents a substantial hazard.
Healthy fish can also be infected when they eat an infected fish. Infected fish and water can easily spread the virus if they are released into a new water body. It is important that anglers, boaters and other water users do not move fish and water from one waterbody to another.
Can birds spread the VHS virus to new waters?
VHS cannot be transmitted through the feces of birds that eat infected fish since the virus cannot survive being passed through a birds' digestive system. Studies in Europe have shown that the European strain of VHS can survive on the feathers or feet of birds that have come in contact with infected fish or water. However, this method of spread is unlikely as it would take many trips of birds between infected and uninfected waterbodies to transfer and create the concentrations of the virus needed in the water to infect fish
Emergency Rules
Vermont Fish & Wildlife has enacted a new Emergency Rule in response to the threat viral hemorrhagic septicemia poses to the state's waters and fish populations. The new rule affects baitfish use in Vermont and is designed to proactively head off the spread of VHS and other fish diseases to the state's waters.
The Emergency Rule, signed into law on October 23, 2007 will be effective for 120 days, expiring on February 19, 2008. A permanent regulation will be adobted by the Vermont Fish & Wildlife Board by Spring of 2008. Hearings to gather public input and comment will be held throughout the state prior to adopting a permanent rule.
Vermont VHS Surveillance Program
Vermont has a surveillance program that tests for fish diseases in hatcheries and wild fish populations. The goals of the surveillance effort are to determine the distribution of fish diseases in both hatchery and wild fish populations, and designate free and infected zones to facilitate disease control. Last year, the surveillance program for wild fish populations was expanded due to the risk of VHS contaminating Vermont waters.
To date, almost 900 individual fish involving 14 different species from Lake Champlain have been tested for Viral Hemorrhagic Septicemia. Fortunately, all individuals tested thus far have been negative.
Next year the Vermont Department of Fish & Wildlife will expand its surveillance program by participating in a program supported by the U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS). The Department plans on collecting and testing nearly 5,000 individual fish for VHS from lakes and ponds statewide. This surveillance program will generate critical information on the probability of fish in a watershed being infected with the disease in Vermont. This information can help us prevent the spread of fish diseases to uncontaminated waters.
What can I do about VHS?
We must all help protect Vermont's wild fish populations to ensure that sport and recreational fishing in Vermont continues to thrive and exist for everyone's enjoyment in the future. It is crucial that all anglers and water users help stop the spread of invasive species and fish diseases such as viral hemorrhagic septicemia.
- Help stop the spread of invasive species and fish diseases !
- Understand and follow all Fish & Wildlife regulations pertaining to baitfish use, fish importation and fish movement.
- Inspect your boat, trailer, and all equipment and remove any visible aquatic plants, animals, and mud.
- Drain all water from your boat, motor, bilge, live wells, and bait containers before leaving the waterbody.
- Do not move live fish, including baitfish, from one water to another.
- Never leave waters with any live fish or fish eggs.
- Dispose of leftover bait in the trash, not in the water or on land.
- Buy your baitfish from licensed Vermont bait dealers.
- Wash your boat and equipment with high pressure or hot water, or let it dry for five days between waterbodies.
Frequently Asked Questions about the Emergency Baitfish Rule
Why was this emergency rule put into effect?
The emergency rule was implemented to prevent the spread of viral hemorrhagic septicemia (VHS) and other diseases into Vermont waters. VHS is primarily spread from fish to fish, and so moving wild fish from water to water through stocking or baitfish use can potentially introduce the disease to new waters. An analysis of the risks surrounding fish movement with respect to fish disease determined that the harvest, movement, and use of wild fish, particularly baitfish, poses the highest risk and therefore this pathway must be controlled. Consequently, wild fish can no longer be imported into Vermont, and wild baitfish can no longer be harvested from Vermont waters.
Is this emergency rule the final regulation that will be permanently adopted?
No. This law is currently an Emergency Rule, and as such, it is effective for 120 days only. The emergency rule will expire on February 19, 2008. Beginning in January of 2008, a permanent regulation will be presented to the Vermont Fish & Wildlife Board for consideration. As part of this permanent rule adoption process, public input and comment will be received via hearings that will be held around the state.
If VHS is only in the Great Lakes, why restrict the use of wild baitfish from Vermont?
VHS has spread quickly through the Great Lakes and into several inland waters in some Great Lakes states. In every case, the existence of the virus was not detected until fish began to die in large numbers. Evidence suggests that the virus is likely present in a waterbody for one or more years before causing noticeable fish kills. Although we have been testing Lake Champlain fish for the VHS virus, we cannot be 100% sure that it is not present there or in other Vermont waters at this time. To suitably eliminate the risk of spreading the virus, we must control all fish movement at this time. In 2008, Vermont will be significantly increasing its VHS surveillance program state-wide.