New virus could devastate fish farms

PIKETON, Ohio – A newly emerging fish virus spreading among wild species is causing concerns in Ohio’s farmed aquaculture industry. But testing fish farms for the disease can help contain it.
Contagious virus. Viral hemorrhagic septicemia (VHS) is a highly contagious and deadly virus that has been spreading like wildfire in over three dozen wild fish species throughout the Great Lakes region for the past two years.
The disease was first identified in Lake St. Clair in 2003. Just last month, VHS virus was identified in inland waters in Michigan and Wisconsin.
How far the disease has spread south remains unclear, but officials want to make sure it never finds its way to any fish farms in Ohio.
“VHS is a nasty disease that can do a number on fish, especially in a confined area,” said Geoff Wallat, an Ohio State University aquaculturist with the South Centers at Piketon.
Devastating. “If that disease ever got onto a fish farm, it could be devastating. Fish farms in Europe infected with VHS have seen 80 percent to 90 percent losses.”
Wallat, who holds a research appointment with the Ohio Agricultural Research and Development Center, is serving on the Ohio Department of Agriculture’s Fish Health Advisory Committee as a university aquaculture expert.
He has been leading OSU Extension efforts to educate the public on what VHS is and the dangers of transporting live susceptible species from the Great Lakes within the state and out of state.
According to the U.S. Department of Agriculture Animal and Plant Health Inspection Services, eight Great Lakes states are prohibited from transporting live VHS-susceptible species to other states, unless diagnostic testing has been performed on the fish shipment.
Affected states. Those affected states include: Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania and Wisconsin.
Additionally, two Canadian provinces, Ontario and Quebec, are prohibited from importing VHS-susceptible species to the United States. Both prohibitions come with certain exceptions, such as catch and release activities, and movement to slaughter facilities and research and diagnostic labs.
Wallat said the regulations were put in place to help protect the aquaculture industry, which uses many of the wild species susceptible to VHS virus for breeding stock.
In Ohio, such species include bluegill, yellow perch and walleye.
“The threat is there to potentially spread VHS virus to Ohio fish farms if farmers don’t follow the established regulations,” said Wallat.
“But the overall concern of VHS showing up in the state’s aquaculture facilities is fairly low because many aquaculturists don’t use wild species as breeding stock – the majority are self-contained – and many facilities are not large enough businesses to ship live fish out of state.”
Get tested. Stopping or slowing the spread of VHS virus is still important, and one way fish farmers can do their part is to have the fish in their facilities tested for the presence of the disease. If the results come back negative, their operation is marked as VHS-free certified.
“If a fish farmer is going to ship live fish interstate, they are required to have their facilities tested. Even if that is not the purpose of the business, having the fish tested for VHS is a recommendation, especially if a farmer has incorporated wild fish in his stock over the past four year,” said Wallat.
“It’s peace of mind knowing that the fish are disease-free and an insurance for others that do business with those operations that the stock is not carrying the disease.”
He added that if a facility does test positive for VHS virus, it must be reported to the Ohio Department of Agriculture. The aquaculture facility at OSU South Centers at Piketon is already VHS-free certified.
Approximately 125-150 reported fish farms exist in Ohio, and only a small percentage of that number has been tested for VHS.