Great Lakes Radio Consortium:
http://glrc.org/story.php3?story_id=3266
VIRAL DISEASE KILLING GREAT LAKES FISH
Lester Graham
January 1, 2007
A disease is spreading, causing large fish kills in the Great Lakes. Biologists and fishery officials are working to prevent further spread of the disease, but there's a conflict between government agencies. Lester Graham reports there's also a cost to businesses that deal in live fish:
The disease that's killing fish is called Viral Hemorrhagic Septicemia -- or VHS. Jim Diana is a fish biologist at the University of Michigan who's been looking into what it does to fish…
"So, it's a virus that the fish pick up and the virus causes really kind of a general systemic deterioration. Most notable, sometimes they'll develop sores or lesions on the outside of the body, but they often will die without really external evidence at all."
Basically, the fish die from internal bleeding. For several years there have been die-offs in the St. Lawrence River, which connects the Great Lakes to the Atlantic Ocean. But researchers weren't able to confirm the cause was VHS. Then this past summer in Lake Saint Clair -- the lake near Detroit that lies between Lake Huron and Lake Erie -- Jim Diana says fish die-offs were confirmed to be caused by VHS.
"And since then, they've found it in quite a few other species, something like 20 other species, so it's quite widespread."
It's not clear how the virus got here. But… it originated in Europe. Researchers guess that infected fish hitchhiked in the ballast tanks of a ship… or a live fish shipment escaped into the St. Lawrence River and it's spread from there by ship.
Biologists say the spread of VHS is not good. It's not expected to wipe out fish in the Great Lakes. But it is causing some real concern.
"We're not talking about a couple of fish here, we're talking about large fish kills. And VHS is present in those and implicated in the deaths of those fish."
Marc Gaden is with the Great Lakes Fishery Commission. Gaden says because stocking fish is a big industry… there's a lot of fish shipped between the U.S. and Canada and between one state and another.
"So, in the Great Lakes basin there is a movement of fish, fish eggs and other fishery related things like water that's used in the fish stocking trucks, things like that. There's aquaculture that occurs, fish farms in the Great Lakes basin. The Departments of Natural Resources harvest fish eggs to use in their stocking programs and the fish themselves are stocked. So, there's movement of fish and fish eggs throughout the Great Lakes basin just as a normal part of fisheries management and commerce that occurs."
So the chance that the virus can be spread by all those fish moving around is significant. The federal government thought it was such a risk that it banned all fish shipments. The states quickly appealed that. They said it was overkill. They persuaded the feds that they were doing enough testing that the chances that VHS would be spread were slim.
So, the feds backed off a bit. But restrictions are still causing some problems. For example… live fish that are not going to be put back into the lakes… live fish that are headed for dinner plates at restaurants still have to be tested. And VHS poses no risk to human health.
Ted Batterson is the director of the North Central Regional Aquaculture Center at Michigan State University. He says he knows one fish farmer whose business is supplying rainbow trout to restaurants.
"Well, now to be able to do that, he has to have the certification that these are VHS-free. It takes him currently, with the laboratory he's been sending these to, up to 90 days to get the certification that these are disease free. Well, that is not timely because these people who want fish at the other end need them in essence like yesterday, not 90 days down the road."
Another business hit by the restrictions on moving live fish is the bait industry. If the bait industry has to test –for example—one out of every 50 fish… and the test costs about 50-dollars… no one will be able to afford to sell bait fish.
The states and the feds are still trying to figure out how to prevent the spread of VHS… without hurting the businesses that rely on live fish shipments any more than necessary. But… some businesses are already feeling the squeeze.
For the Environment Report, this is Lester Graham.
