May 22, 2007
Expert: Aquatic Virus Hits 2 Great Lakes
SYRACUSE, N.Y. -- A deadly, fast-spreading aquatic virus is reaching epidemic proportions in New York's two Great Lakes and has already spread into the Finger Lakes region in upstate New York, a Cornell University fisheries expert said Tuesday.
The viral hemorrhagic septicemia virus - or VHS - has now been identified in 19 species in Lake Erie and Lake Ontario, including muskellunge, New York's No. 2 sport fish, said Paul Bowser, a professor of aquatic animal medicine in the College of Veterinary Medicine.
Equally alarming, said Bowser, is the confirmation of VHS in walleye in Conesus Lake, which is the westernmost Finger Lake and is the only New York lake where VHS has been confirmed in a body of water other than the contiguous waters of the Great Lakes.
"The fact that VHS was found in this inland body of water is particularly disturbing in that it immediately brings up the question of how did it get there and what can be done to prevent the virus from moving to other bodies of water," said Bowser, who along with his colleagues at Cornell recently developed a new test that can identify the virus within 24 hours.
VHS was first detected in New York last year in fish from the St. Lawrence and Niagara rivers, as well as the state's two Great Lakes.
Of the 19 species affected, VHS has caused serious fish kills in six, Bowser said. In the remaining 13 species, Cornell scientists have detected the virus but have recorded no "mortality events," he said. There are approximately 150 species of freshwater fish in New York.
"It has been found in a broad range of evolutionarily distinct species, both cold- and warm-water families. We don't think there is any species that is not susceptible," said Doug Stang, chief of the New York Department of Environmental Conservation's Bureau of Fisheries, which is monitoring 40 water bodies across the state to track the spread of VHS.
Bowser said he suspects that the virus is spread by airborne or terrestrial predators carrying infected fish, anglers using infected bait minnows or contaminated fishing equipment, and as a result of boating activities.
"Basically, we don't know how it got here, but it's here and it's spreading," said Bowser.
The virus, which causes internal bleeding in fish but poses no threat to humans, was discovered in the United States in 1988 in Coho and Chinook salmon in the Pacific Northwest. VHS made its first known appearance in the Great Lakes in 2005, killing freshwater drum and muskellunge.
Since then, it has been found in more than two dozen fish species throughout the Great Lakes basin.
This month, the Wisconsin Department of Natural Resources made a preliminary identification of the virus for the first time in the Lake Winnebago chain of inland lakes about 25 miles south of Green Bay on Lake Michigan. Confirmation is pending.
VHS-related die-offs killed millions of fish in Lake Erie and Lake Ontario last year. There have been three new fish kills this year in New York waters, Bowser said.
In the St. Lawrence River, hundreds of thousands of round gobies have succumbed and gizzard shad die-offs occurred in Lake Ontario west of Rochester and in Dunkirk Harbor on Lake Erie, he said.
"In that most of our VHSV-associated fish kills in 2006 were in May and June, we expect more to occur," Bowser said.
Other species that have tested positive include bluegill, rock bass, black crappie, pumpkinseed, smallmouth and largemouth bass, northern pike, yellow perch, channel catfish, brown bullhead, white perch, white bass, emerald shiner, bluntnose minnow, freshwater drum and burbot.
Containing the spread of the virus in New York will require restrictions on the movement of live fish, testing fish and surveillance, Bowser said.
"There will be inconveniences and disruptions that will occur. However, to do nothing could be disastrous," said Bowser, adding that VHS threatens the state's $1.2 billion sport-fishing industry and could have a devastating effect on aquaculture.
Last year, New York enacted a series of emergency regulations to curb the virus' spread, such as requiring that bait fish be used in the same body of water from which they were collected unless they have been tested. Those regulations will likely become permanent next month, said DEC spokeswoman Maureen Wren.
On the Net:
DEC emergency regulations: http://www.dec.ny.gov/press/28757.html