Fish-Killing Virus Spreading in the Great Lakes

[Hum]

CHICAGO, April 20 ? A virus that has already killed tens of thousands of fish in the eastern Great Lakes is spreading, scientists said, and now threatens almost two dozen aquatic species over a wide swath of the lakes and nearby waterways.

The virus, a mutated pathogen not native to North America that causes hemorrhaging and organ failure, is not harmful to humans, even if they eat contaminated fish. But it is devastating to the ecosystem and so unfamiliar, experts said, that its full biological impact might not be clear for years. It is also having a significant impact on the lakes? $4 billion fishing industry.

There is no known treatment for the virus. As a result, scientists are focusing on managing its spread to uncontaminated water ? quite a challenge since the Great Lakes are linked and fall under the jurisdiction of several states and provinces in Canada.

?Updates over the winter suggest it has spread further than we thought, even last year,? said John Dettmers, a senior fisheries biologist for the Great Lakes Fisheries Commission in Ann Arbor, Mich.

?It?s really early,? Mr. Dettmers said. ?As much as I?d like to say we know exactly what?s going on, we don?t. We?re all sitting here on the edge of our chairs waiting to see how bad it?s going to be this year.?

When it was first detected about two years ago, the virus had affected only two species in a limited amount of water. But it has aggressively spread to other areas and other fish and is now being confirmed in Lake Huron after infecting Lakes Ontario and Erie, Lake St. Clair, the St. Lawrence River and the Niagara River. It is suspected in Lake Michigan as well, although there is no official confirmation.

Last year, the virus, called viral hemorrhagic septicemia and known as V.H.S., caused untold thousands of dead fish to wash up in places like the eastern shoreline of Lake Ontario, a warning sign that scientists said could just be the tip of the iceberg in terms of what is going on underwater.

The five Great Lakes ? Superior, Erie, Huron, Michigan and Ontario ? hold 20 percent of the world?s fresh surface water.

?We anticipate that this will continue and get worse over the next few years,? said Dr. Jim Casey, associate professor of virology at Cornell University. ?We fear there may be more widespread presence of the virus.?

One of Dr. Casey?s colleagues researching the virus, Dr. Paul Bowser, a professor of aquatic animal medicine, added, ?This is a new pathogen and for the first number of years ? 4, 5 or 10 years ? things are going to be pretty rough, then the animals will become more immune and resistant and the mortalities will decline.?

No one is sure where the virus came from or how it got to the Great Lakes. In the late 1980s, scientists saw a version of V.H.S. in salmon in the Pacific Northwest, which was the first sighting anywhere in North America. V.H.S. is also present in the Atlantic Ocean. But the genesis of a new, highly aggressive mutated strain concentrating on the Great Lakes is a biological mystery.

?We really don?t know how it got there,? said Jill Roland, a fish pathologist and assistant director for aquaculture at the U.S. Department of Agriculture. ?People?s awareness of V.H.S. in the lakes was unknown until 2005. But archived samples showed the virus was there as early as 2003.?

Scientists pointed to likely suspects, mainly oceangoing vessels that dump ballast water from around the world into the Great Lakes. (Ships carry ballast water to help provide stability, but it is often contaminated and provides a home for foreign species. The water is loaded and discharged as needed for balance.)

Fish migrate naturally, but also move with people as they cast nets for sport, for instance, or move contaminated water on pleasure boats from lake to lake.

The United States Department of Agriculture issued an emergency order in October to prohibit the movement of live fish that are susceptible to the virus out of the Great Lakes or bordering states. The order was later amended to allow limited movement of fish that tested negative for the virus.

?Getting rid of it is extremely hard to foresee,? said Henry Henderson, director of the Natural Resources Defense Council?s Midwest office in Chicago. ?These species spread, and reproduce. It is a living pollution.?

source

[Fresh]

Bush or Global Warming cause this? :woot:

[Fred Derf Veteran]

Bush or Global Warming cause this? :woot:

"Scientists pointed to likely suspects, mainly oceangoing vessels that dump ballast water from around the world into the Great Lakes. (Ships carry ballast water to help provide stability, but it is often contaminated and provides a home for foreign species. The water is loaded and discharged as needed for balance.)"

[kevbo]

I thought the Great Lakes have been contaminated for years? It's not like you can eat the fish in this area, anyway. The mercury scare has gotten the best of our fish eating abilities :(.

[popsmear]

I thought the Great Lakes have been contaminated for years? It's not like you can eat the fish in this area, anyway. The mercury scare has gotten the best of our fish eating abilities :(.

Uh no?

http://www.michigan.gov/documents/FishAdvisory03_67354_7.pdf

You can east most of the fish.

[kevbo]

Yeah, but the mercury scare was people telling us that pregnant women, young children, and elderly shouldn't eat the fish, so everyone magically turns into a "catch-and-release" fisher... At least in my area. I guess I can't speak for the rest of the region...

[Fred Derf Veteran]

I thought the Great Lakes have been contaminated for years? It's not like you can eat the fish in this area, anyway. The mercury scare has gotten the best of our fish eating abilities :(.

Due to the direction of the water, all contaminants from Lake Superior or Lake Michigan through to Lake Ontario and then out the St. Lawrence River. Basically, I am saying that it is good to be upriver. Lake Erie used to be very polluted but I understand that it has been cleaned up somewhat. Lake Erie is relatively shallow so that adds to their problem.

An invasive species of Zebra Muscles has actually helped to filter the water somewhat and plants can now grow at deeper depths. Zebra Muscles also likely arrived from dumped ballast water. They have no natural predators in North America.