Koi herpes caused similar carp die-off in New York
Author: Kathryne Miller

Researchers at Cornell University in Ithaca, New York are watching with great interest the situation in local lakes that has seen carp dying by the thousands.
They were themselves involved in a similar situation in 2005 at Chautauqua Lake in western New York State.
Just as the summer tourist season was swinging into gear, they were dealing with 20,000 dead carp in the lake.
Scientists at the veterinary college at Cornell pinpointed the cause of that outbreak to KHV, or Koi herpes.
They say it looks like we could be dealing with a virus here.
"If the situation is that you have large numbers of just one type of fish dying, then there is a possibility that it is a virus," says Dr. Jeff Groocock or Cornell.
There have been reports that University of Guelph researchers have found evidence of Columnaris bacteria in dead carp retrieved Sturgeon Lake.
Cornell research associate Rod Getchell says Columnaris and KHV display a lot of the same clinical signs, such as rotting tissue around the gills.
The scientists say the progression of the problem here is also symptomatic of viral movement.
They say if it turns out to be a virus, there's nothing that can be done except to let the disease run its course.
http://www.mykawartha.com/article/12529

Bacteria may be killing Kawartha lake carp
Last Updated: Wednesday, July 11, 2007
CBC News Canada/Toronto

A type of bacteria may be responsible for the thousands of dead carp washing ashore from the Peterborough-area Kawartha Lakes, Ministry of Natural Resources officials said Tuesday.

Researchers at the Unviersity of Guelph in southwestern Ontario found flavobacterium columnare in some of the fish samples from Sturgeon Lake. The same bacteria was responsible for the death of catfish, bass and turtles along the Ottawa River last summer.

The bacteria have only turned up in Sturgeon Lake samples, and may not be the sole cause of death, officials said. Scientists are still investigating.

Ministry biologist Dan Taillon said scientists believe the bacteria will not affect humans. The optimal temperature for the bacteria to grow is about 22 C, while bacteria that cause health concerns normally need temperatures above 40 C.

"The human body is an inhospitable environment for flavobacterium columnare to grow," he said.

Taillon said people handling the fish should wear gloves and wash afterwards as a precaution. As for eating fish from the lakes, he said, cooking should kill any bacteria that may be present.
http://www.cbc.ca/canada/toronto/story/2007/07/11/carp-bacteria.html

Hot Rogue water could harbor deadly salmon virus

July 12, 2007
Southern Oregon Mail Tribune

AGNESS — The dark silhouettes of hundreds of Rogue River chinook salmon taking respite in the relatively cool waters of Hotel Riffle should make fishing guide Steve Beyerlin giddy.

Instead, the image is perhaps a grim foreshadowing of the future for the Rogue's fall chinook run.

Overstressed from the river's hot water, these salmon are taking refuge this week in Hotel Riffle because it is just downstream from the Rogue's confluence with the cooler-flowing Illinois River.

Their presence is a sign of how desperate these chinook are. And it's an indication to Beyerlin that these chinook likely won't survive to migrate upstream to the Rogue Valley.

"I just don't see how they're going to make it," Beyerlin says. "They won't be swimming forward. They'll be floating upside down and backwards."

That's what happens when the natural warm-water disease called columnaris breaks out in the lower Rogue during the fall chinook run, sometimes killing more than half of the fish before the survivors can reach Grants Pass.

A combination of relatively low flows and triple-digit air temperatures in the Rogue Valley have sent Rogue temperatures soaring here in Agness, a small river outpost that is 27 miles east of Gold Beach and just one-fourth of the salmon's trek toward Grants Pass.

A gauge at Agness reveals water temperatures above 77 degrees, enough in past years to trigger columnaris outbreaks.

So far, no dead chinook have been discovered, but state biologists have asked Mail Boat excursion jetboat drivers out of Gold Beach to keep their eyes open for the upside-down, backwards-floating salmon that Beyerlin fears.

"There's no question temperatures at the Agness gauge are up there," says Dan VanDyke, the Rogue District fish biologist for the Oregon Department of Fish and Wildlife. "With the low flows and hot temperatures, it certainly is possible that we could lose fish from columnaris this year."

VanDyke already has asked the Oregon Water Resources Department and the U.S. Army Corps of Engineers to keep water releases from Lost Creek Lake a bit higher than planned for July, during what is the end of the spring chinook migration.

Another chunk of Lost Creek Lake water already is set aside for release in August to curb a columnaris outbreak.

Beyerlin believes the chinook at Hotel Riffle won't make it that long.

"Barring a major rain event, they're toast," Beyerlin says.

Natural to the Rogue, columnaris is a virus that spreads through warm water in the lower river, most often during hot summers and amid drought-like conditions.

Columnaris attacks the fish's gills and suffocates them, but it poses no threat to humans in contact with the water or those who eat sport-caught salmon.

It is highly infectious to chinook, particularly fall chinook that migrate through the lower Rogue in August, which tends to sport the hottest water temperatures. However, the virus does not harm summer steelhead, which also are present in the Rogue during the same period.

Outbreaks are most common in the Lower Rogue Canyon, where water temperatures are some of the highest measured each summer in the river.

The further upstream, the cooler the water. That's why outbreaks are considered extremely rare in the upper Rogue.

This week's conditions are a near-mirror image to those in mid-July of 1992, when triple-digit temperatures in Medford helped cook water flows that measured 77 degrees in Agness, triggering a die-off like the one Beyerlin now foresees.

A similar outbreak killed about 20 percent of the Rogue's spring chinook run in 2001. Drought-triggered outbreaks in 1992 and '94 resulted in the loss of 60 percent of the spring chinook runs, and the '92 die-off triggered a sport-fishing closure on the upper Rogue to protect the spring chinook that survived.

Managing salmon around columnaris is just part of the fabric of the Rogue. In fact, outbreaks among fall chinook once were the rule, not the exception.

Before Lost Creek Lake began operation 30 years ago, regular columnaris outbreaks kept the Rogue's production of the all-wild fall chinook run to a minimum.

But water releases from Lost Creek Lake and, to a lesser extent, those from Applegate Lake have kept the lower Rogue high and cool enough most years to stave off an outbreak. That has allowed for an explosion of fall chinook that fortifies a largely successful late-summer fishery from Gold Beach to Gold Ray Dam.

So those several hundred chinook hunkered down in Hotel Riffle represent just a sliver of what is to come.

"I fear those fish will disappear," Beyerlin says. "They'll be floating backward."
http://www.mailtribune.com/apps/pbcs.dll/article?AID=/20070712/SPORTS/707120328

From the AKCA Online Library:

"Columnaris flexibacter also occurs in koi. It appears in warm water and can be seen as fin and body rot, saddleback lesion, mouth fungus, cloudy eye, gill disease, or even death with no lesions. Antibiotics used to treat this infection include sulfa drugs, tetracycline, and nitrofurans. However, since Aeromonas often is seen in conjunction with this infection, antibiotic injection may still be the best treatment.
As a personal note, I would add that most bacterial infections appear as ulcers, and once ulcers appear injection of fish should be considered. If you are not comfortable with giving injections, then antibiotics can be added to food and water. If too many antibiotics are used for too short a time or at too low a dose, bacteria can become resistant to the antibiotics. This must be avoided as there are a limited number of antibiotics available to the hobbyist for treating bacterial infections.

Organics in the pond water can alter the amount of antibiotic available for the fish to absorb. Therefore, Dr. Gratzek recommends doing a water change before adding antibiotics to the water and a major water change 4 hours later to avoid exposing the fish to low doses of antibiotic over long periods of time. Water hardness may also affect the dosing level of antibiotics. Antibiotics can be added to food, and Dr. Gratzek suggests mixing it in cod liver oil to make it stick to the food. His instructions for mixing food include using 100 to 250mg of antibiotic mixed with a shot glass of cod liver oil added to 1 and 1/2 cups of food. Then lay out the food to dry and blot. For bacteria in general, Dr. Gratzek suggests using formaldehyde first and then antibiotics. Guidelines include using correct dose, minimal time, ending treatment by water change after 4 hours, aeration, and stop filter. Experiments were done and the results suggest that of all the medications and antibiotics we use in our ponds, the only one that seems to harm the filter is methylene blue. Fungus and viruses will be the topic of the next article."
http://www.akca.org/library/koimed1.htm

Columnaris not a Threat According to Art Lembke? Letter to AKCA Leaders July 12, 2007