Great Lakes scare over fish-killing virus

[kach22i]

Great Lakes scare over fish-killing virus
http://www.msnbc.msn.com/id/16825280/from/RS.4/

TRAVERSE CITY, Mich. - A fast-spreading aquatic virus that threatens
the
Great Lakes fishing industry has been detected in Lake Huron for the
first time, Michigan officials said Thursday.


The Department of Natural Resources said it had confirmed the presence
of viral hemorrhagic septicema, or VHS, in fish samples from waters as
far north as Cheboygan — only about 15 miles from where Lake Huron
meets
Lake Michigan.


VHS previously had been found in only two Great Lakes — Ontario and
Erie
— and in Lake St. Clair, which links Erie and Huron. But officials
have
predicted the virus eventually would spread across the entire system,
where the $4.5 billion fishery is a crucial segment of the economy.


How damaging the virus turns out to be will depend largely on whether
fish develop immunity, said Kelley Smith, chief of the DNR's fisheries
division.


The virus poses no danger to people but is usually deadly to fish. It
targets some of the region's most popular sport and commercial species.


Analyses completed this week found VHS in whitefish and walleye, and in
Chinook salmon from a DNR station, Smith said.


Originally a saltwater virus, VHS made its first known appearance in
the
Great Lakes in 2005, killing the likes of freshwater drum and
muskellunge.


Cheboygan-area whitefish were collected in 2005 during a survey for
bacterial kidney disease, Smith said. They were examined again more
recently and found to have carried VHS.


How VHS arrived in the lakes is uncertain. But fishery managers say a
likely culprit is ballast water dumped by ocean freighters, widely
considered a leading source of exotic species in the lakes.


"These new discoveries are extremely unfortunate and further highlight
the problems created by the constant introductions of new diseases from
outside the Great Lakes region," DNR Director Rebecca Humphries said.