Virus that can kill fish is found in lake for the first time
Written by Rochester Democrat & Chronicle   
Tuesday, 20 June 2006 13:02

A deadly virus that can infect nearly every species of fish in Lake Ontario has been found in the lake for the first time. The virus, known as viral hemorrhagic septicemia, has been detected in both round gobies, an invasive species, and muskellunge, a native fish, according to the Department of Environmental Conservation.

The infected gobies were in the St. Lawrence River, and the muskellunge in northeastern Lake Ontario.

While the virus can't be transmitted to humans, it can cause up to 80 percent mortality in fish.

The disease hasn't yet been seen in Lake Ontario trout or salmon populations.

But different strains of the virus have decimated rainbow trout in hatcheries in Europe and have infected Pacific salmon in Puget Sound.

"It does affect many species. There's no way to know how far it's going to go," said Geoffrey Groocock, a veterinarian at Cornell University's aquatic animal health program.

If sport fish populations in Lake Ontario become infected, western New York would lose millions in tourist dollars.

Groocock and his colleagues are investigating which species are most susceptible to this strain of the virus.

In the meantime, DEC does not believe trout and salmon to be at high risk of infection.

State biologists became aware of the problem when a large die-off of round gobies occurred in the St. Lawrence River in May. Samples from the bodies of the dead fish were sent to Cornell, in Ithaca.

After weeks of analysis, the lab verified several ways that the fish were infected with viral hemorrhagic septicemia.

The virus has been detected in Michigan and Canada but this is the first incidence in New York.

Scientists don't yet know how the virus made it to the mouth of the St Lawrence.

The disease may have traveled east with advancing round goby populations.

Or it may have been introduced separately.

"It looks like the virus has been in the lake for a least a year or two," Groocock said, basing his estimate on the number of infected gobies.

The virus is spread by a fish's bodily fluids.

Some also believe that it can be spread by infected water.

Some species of fish also survive the virus to act as carriers.

In Europe and Japan, viral hemorrhagic septicemia is a significant problem.

Most of these infestations have occurred at hatcheries and fish farms.

Researchers don't believe that the New York hatcheries system is infected.

"If it was in the hatcheries, with the density of fish, we would have had an outbreak," Groocock said.

New fishing regulations aren't believed necessary, said DEC spokeswoman Maureen Wren.

However, fishermen are asked to follow state guidelines for reducing the spread of invasive species. New York:


  • Prohibits the use of round gobies as bait.

  • Recommends that fishermen never release plants, fish or animals into a body of water unless they came out of that body of water.


  • Encourages boaters and fishermen to clean their equipment before traveling from lake to lake.

    "We don't want it to get out of the Great Lakes system and into the Finger Lakes," Groocock said.
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