Virus is Culprit for Fewer Muskies in St. Lawrence

[Hamilton Reef]

Researchers Say Virus is Culprit for Fewer Muskies in St. Lawrence

http://www.greatlakesdirectory.org/ny/0 ... _lakes.htm

Associated Press Published on newswatch50.com on August 3, 2007

(Syracuse, N.Y.) AP -- A highly contagious fish virus is killing off muskellunge in the St. Lawrence River, scientists said Wednesday.

Researchers caught more than 40 muskellunges during the spring spawning run in 2003 at the school's Thousand Islands Biological Station on Governor's Island, according to the State University of New York's College of Environmental Science and Forestry.

Last year, they captured only 12 to measure and tag. This year, there were four.

"We want to send out an alarm that VHS is killing muskellunge," said the station director, Dr. John Farrell, referring to viral hemorrhagic septicemia.

Muskies are one of the state's top-rated sport fish.

Scientists with the state Department of Environmental Conservation and Cornell University have identified VHS-infected fish in Lake Ontario, Lake Erie, the Niagara River, the St. Lawrence River, Conesus Lake and Skaneateles Lake. Last month, they found it had spread to the Little Salmon River, the Seneca-Cayuga Canal and a farm pond in Niagara County.

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.

Farrell said that before 2005, he and his colleagues typically saw one dead muskellunge once every few years. As the largest predator in the ecosystem, there are naturally fewer muskellunge in the river than other fish.

In 2005, researchers came across 25 muskellunge carcasses. In 2006, they found about a dozen - all large females, and including one that was 59 inches long. Tests showed that several of them died from VHS.

"They were all females with eggs that had not spawned. Now we're looking into the impact of losing large mature individuals from the population," Farrell said. "We haven't seen mortality events like this in the past."

As of the end of June, about a half dozen muskellunge had turned up dead in the river, he said. Additionally, the biological stations monitoring efforts show there are fewer young muskellunge and fishermen are reporting fewer catches than in the past.

In New York, VHS has been identified in nearly two dozen species since first appearing last year.

In May, the DEC established regulations restricting the movement of bait fish and the stocking of fish into New York's waters. Despite the measures, VHS continues to spread. There is no known cure for VHS, which has caused fish kills in New York ranging from a few to thousands of fish.