Fish-killing virus spreads, threatens fishing industry in Great Lakes


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.

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.