The Wisconsin State Department of Natural Resources (DNR) on Friday May 17 announced that fish collected in several Lake Winnebago locations preliminarily tested positive for viral hemorrhagic septicemia or VHS, a deadly fish virus that officials have suspected for years may have already appeared in Lake Michigan and Superior and the Mississippi River.
The fish virus has already been found in two drum, or sheepshead, collected on May 2 from Little Lake Butte des Morts, the DNR announced May 12. Dead fish were discovered in Lake Winnebago earlier. Since May 2, DNR has been receiving reports of hundreds of freshwater drum dying on Lake Winnebago, according to the state agency.
Little Lake Butte des Morts is in downstream from Lake Winnebago and separated by one dam and one functioning lock. The Lake Winnebago chain is home to Wisconsin’s unique sturgeon population. The finding of VHS in Little Lake Butte des Morts and dead fish in Lake Winnebago prompted state officials to immediately close the lock effective May 12 to prevent the fish virus from spreading to Lake Winnebago.
As fish from Lake Winnebago have been found infected with the fish virus, officials on Friday ordered re-opening of the Menasha lock because the closure does no longer help prevent the spreading of the fish virus.
The fish virus does not pose any risk to people who eat the infected fish. However, it is lethal to more than 25 fish species in Wisconsin Waters. State Officials worry that VHS could spread to many lakes in the state, potentially devastating fish populations and affecting the 2.3 billion fishery industry in the state.
The fish virus caused major fish kills in 2005 and 2006 in lakes St. Clair, Erie, Ontario and the St. Lawrence River, and the virus was discovered in Lake Huron fish in February, according to Mike Staggs, Wisconsin’s fisheries director.
The latest discovery of the fish virus in some Wsiconsin lakes does not come as a surprise to the officials who are aware that the risk is always there for the virus to spread. Because of this, the state Natural Resources Board already convened on April 7 to address the potential spread of VHS to fish in Wisconsin's inland waters.
At the meeting, the Board unanimously passed emergency rules prohibiting anglers and boasters from moving live fish and requiring that they drain their boats and livewells before leaving Wisconsin's Great Lakes waters, the Mississippi River and those waters' tributaries up to the first dam.
As the fish virus was found in fish from Lake Winnebago on Friday, the Broad extended emergency rules adopted on April 7 to include the Lake Winnebago watershed. The board's also extended the emergency rule statewide if VHS is found outside of the Lake Winnebago system.
Wisconsin has been already testing a wide variety of fish in Lakes Michigan and Superior and the Mississippi River for the fish virus VHS since 2005. New monitoring procedures are being developed to test other water systems. The state also has suspended all stocking of fish, transfers of fish among hatches, collection of forage fish or eggs from the wild and all field fish transfers. And the DNR Secretary Scott Hassett has already appointed a VHS response team to develop recommendations as the situation progresses
What is being done to prevent the spread of VHS? (cited from the DNR)
The Department of Natural Resources has been tracking VHS and testing fish in Lake Michigan and Lake Superior for the disease since fall 2005. The DNR stepped up response planning and preparations in late 2006, when the federal government announced a ban on exporting from Great Lakes states and Canadian provinces fish species susceptible to VHS, and in April and May of this year, the state Natural Resources Board enacted emergency rules to protect Wisconsin's inland waters from the disease. These actions are aimed at preventing the spread of VHS to inland waters by the public, the bait industry, and DNR fisheries management staff. A listing of major actions follows.
To prevent VHS spread by the public:
• The state Natural Resources Board adopted emergency rules in early April requiring that boaters, anglers, people who harvest wild bait, and other people who recreate on Wisconsin waters not move live fish and water from waters suspected of having VHS at the time the original rules were considered: Lake Michigan, Green Bay, Lake Superior, the Mississippi River and their tributaries up to the first dam or fish barrier. Board members passed the emergency rules unanimously.
• In an emergency meeting on May 17, 2007, the Natural Resources Board extended those safeguards to the Lake Winnebago watershed. Further, under the board's action, if VHS is found outside of the Lake Winnebago system the rules will automatically go into effect statewide. The rules also require that people fishing in those waters use minnows purchased only from Wisconsin licensed dealers, or, if harvesting their own minnows, that the bait is used only on the water it is caught in. They also approved a provision that requires bait dealers to have a state permit and tracking system in order to harvest wild bait from any water.
• We have asked the Fox Locks Authority to close the Menasha Lock until the extent of the spread of VHS in the Lake Winnebago system can be assessed. The closure is aimed at preventing fish movement from Little Lake Butte des Morts, where two fish have preliminarily tested positive for VHS.
• We are taking action to alert the public on the steps they can take to help minimize the spread of VHS with brochures, flyers, posting signs at boat landings on the Winnebago System and other waters suspected of having VHS, and other media channels. Statewide radio spots begin Monday.
New requirements for anglers and boaters to keep fish healthy
Emergency rules effect April 2007 and amended May 17 require that boaters, anglers and other recreational users:
Drain all water from your boat, trailer, bait buckets, coolers, and other containers before you leave the landing or shore fishing site location on Lake Michigan, Lake Superior, the Mississippi River, the Lake Winnebago System or their tributaries up to the first dam.
Do not take live fish, including bait fish, away from any Great Lakes, Lake Winnebago or Mississippi River drainage landing or shore fishing location. This includes tributaries up to the first dam.
Do not use "cut" or dead bait from other waters (except when fishing in Lake Michigan, Green Bay, Lake Winnebago, or tributaries).
Do not use minnows unless they were purchased from a Wisconsin bait dealer or you caught the minnows from the place you are fishing.
Draining all water from boats and boating and fishing equipment is strongly recommended after boating or fishing on all Wisconsin waters, as is inspecting your boat and trailer and removing all visible plants and animals. These steps will also help prevent the spread of other diseases and invasive species.
Important Questions and Answers on Viral Hemorrhagic Septicemia (VHS)
What is VHS?
Viral Hemorrhagic Septicemia, known as VHS, is an infectious viral disease of fish that can cause them to bleed to death. It was diagnosed for the first time ever in 2005 in fish in the Great Lakes, and was confirmed as the cause of fish kills in Lake Huron, Lake St. Clair, Lake Erie, Lake Ontario and the St. Lawrence River in 2005 and 2006. VHS virus is not a health threat to people who eat or handle infected fish, but it is a serious threat to fish. Though Wisconsin may experience VHS-caused fish kills, DNR wants to assure anglers that our fisheries are resilient and will recover.
Can I eat my catch?
Yes. VHS is not a health risk for people. We want you to continue to enjoy fishing and eating your catch. Having the virus in Wisconsin waters means that we all need to be more careful when we recreate to avoid accidentally moving fish, plants, and water to new lakes or rivers. You've long been taking many of the same precautions to help keep our lakes free of other invasive species like zebra mussels and rusty crayfish. Wisconsin has thousands of great places to fish and boat. With your help, we can keep it that way.
Why do fish biologists consider VHS a serious threat to Wisconsin fish?
Fish biologists consider the virus a serious threat to Wisconsin fish for several reasons: it can spread easily between fish of all ages, it affects a broad range of our native game fish, pan fish and bait fish as well as "rough" fish, and it often kills fish. This is the first time a virus has affected so many different fish species from so many fish families in the Great Lakes. Wisconsin fish biologists are also concerned that if VHS spreads to Wisconsin's inland waters, which are much smaller than any of the Great Lakes, it could spread rapidly among fish and potentially large numbers of fish within that water could be affected. Thousands of walleye, lake whitefish, freshwater drum, yellow perch, gizzard shad and round gobie died in the Great Lakes die-offs. Many white bass, emerald shiners, smallmouth bass, bluegill, black crappie and northern pike were diseased but did not die in large numbers.
What can I do to help prevent the spread of VHS?
The DNR is asking the public to take precautions similar to those used in stopping the spread of invasive species:
• Put your catch on ice and do not move live fish (including unused bait minnows) away from the landing or shore;
• Drain all water from bilges, bait buckets, live wells and other containers when leaving the landing or shore;
• Use live minnows purchased only from registered bait dealers in Wisconsin or catch it yourself in the same water you fish; and
• Before launching and before leaving for the day, inspect and clean all watercraft for visible plants and animals.
Buy minnows from licensed Wisconsin bait dealers.
Drain all water from boat, live wells, bait buckets, coolers holding fish.
Inspect your boat and remove all visible plants and animals.
Are there any rules related to VHS that I need to be aware of as an angler or boater?
Yes, the state Natural Resources Board has adopted emergency rules that prohibit anglers, boaters and other recreational users from moving live fish, including bait minnows, and water from the Lake Winnebago watershed, Great Lakes, Mississippi River, and those waters' tributaries up to the first dam impassible by fish. The rules also require that people fishing in those waters use minnows purchased only from Wisconsin licensed dealers, or, if harvesting their own minnows, that the bait is used only on the water it is caught in.
Where is VHS from?
VHS virus is considered an invasive species - not native to the Great Lakes. VHS has been found in the past in fish from the Atlantic Coast of Europe and the Atlantic and Pacific coasts of North America. Historically, VHS was known as a very serious disease of farm raised rainbow trout in Europe. The Great Lakes strain of VHS is genetically different than the strains from Europe and the Pacific Northwest. The Great Lakes strain of the virus seems to affect a wider range of freshwater species over a broader range of water temperatures.
How did VHS get into our lakes?
VHS virus is considered an invasive species (not native to the Great Lakes), but scientists are not sure how the virus arrived. The virus may have come in with migrating fish from the Atlantic Coast. It may have hitch-hiked in ballast water from ships or it may have been brought in with frozen Pacific herring imported for use as bait. Because the VHS virus was confirmed in early 2007 in Chinook and walleye that were sampled in Fall 2006, and lake whitefish collected from Lake Huron in late 2005, fisheries biologists believe the virus is probably already in Lake Michigan, which is connected to Lake Huron. Fish may also already have carried the virus to Lake Superior and ballast discharged from ships may have moved the virus to port cities there. A likely way the disease is spread is through moving live fish or water from one water body to another. The disease has been found in three inland lakes, one each in New York, Michigan and Wisconsin, and could have hitchhiked in a live well, bilge water, on a boat or in minnows or other live fish.
How does VHS spread in a fish population? To new lakes?
Infected fish shed the virus into a lake or river through their urine and reproductive fluids. VHS virus can remain infective up to 14 days in water and the virus particles are absorbed into the gills of healthy fish and infect them. 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. So never move live fish, including minnows, from one water body to another and never move water from a water where the virus is suspected or confirmed as present.
Can birds spread the virus?
We don't know yet whether the VHS strain found in the Great Lakes can be spread by birds. But the European strain cannot be transmitted through the feces of birds that eat infected fish - the virus is inactivated in the gastrointestinal track of the birds. The European virus does appear to be able to be transmitted on the feathers or feet of birds that are feeding on a pile of infected fish or sitting in water containing the virus.
What are the symptoms of a fish infected with VHS?
Like many fish diseases, the type of symptoms present in a fish change with the severity of the infection. At low infection intensity, fish may display few to no symptoms. Hatchery or pen-reared fish are much more susceptible to most fish diseases because they are confined. As the infection severity increases, signs include bulging eyes, bloated abdomens, inactive or overactive behavior, bleeding in the eyes, skin, gills and at the base of the fins. Because many of these signs look like those caused by other fish diseases, testing is necessary to determine whether a fish is infected with VHS.
What is the long-term outlook for VHS in the Great Lakes and state fish populations?
It's hard to say because the disease is so new to the Great Lakes. Fish that survive the infection will develop antibodies to the virus. Antibodies will protect the fish against new VHS virus infections for some time. However, the concentration of antibodies in the fish will drop over time and the fish may start shedding virus again. This may create a cycle of fish kills that occurs on a regular basis. However, experiences from other states indicate that fisheries can and have bounced back. We are still going to have a lot of fish in our lakes and rivers for anglers to catch and enjoy.
What should I do if I see a fish kill or diseased fish?
If you catch a fish that exhibits the above-mentioned VHS symptoms, please place the fish in a plastic bag on ice in a cooler and call your local DNR office or DNR's Central Office at 1-800-TIP-WDNR. If you observe a fish kill, please contact your local DNR office or DNR's Central Office at 1-800-TIP-WDNR.