Cornell researchers are fine-tuning a new technique they developed to rapidly detect a deadly fish virus that has increasingly appeared in the Great Lakes and neighboring waterways. Current tests take a month, while the new technique, which measures viral genetic material, takes only 24 hours to identify the virus.
The viral hemorrhagic septicemia virus (VHSV) has been isolated in a wide variety of dead fish from the St. Lawrence River, the Niagara River, Lake St. Claire, Lake Erie and Lake Ontario. Most recently the virus was detected in Lake Huron only 22 miles from Lake Michigan. VHSV has caused large fish kills and has been detected in muskellunge, New York's number two sport fish.
Cornell's College of Veterinary Medicine is set to receive a two-year $181,000 grant from New York Sea Grant to develop the genetics-based test to spot the virus in both tissue and water samples. The grant also will be used to study optimal ways of handling specimens to be sent for testing.
"The virus is very unstable," said Paul Bowser, Cornell professor of aquatic animal medicine and one of the grant's lead investigators. "If fish are collected by a field biologist in a remote location and they are not properly refrigerated, the virus will decompose by the time it reaches the lab."
The researchers also will investigate the virus' stability in fresh and turbid water to see how these conditions impact detection.
The grant will specifically focus on muskellunge fisheries in the St. Lawrence River, Chautauqua Lake and the Niagara River to determine the pathogen's prevalence in these populations and at different times of year.
Cornell received more than 1,300 fish samples between May and December last year, and researchers have tested all of them using the new technique. They are about two-thirds of the way through testing the same samples using the older technique, which relies on cell cultures, to compare results.