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Mark Freeman's Commentary Nature wreaks havoc on chinook Debi Urie cannot forget the surreal spring of 1992, when the serene beauty of the Lower Rogue Canyon was cloaked in so much death that it made her wretch. Hundreds of dead spring chinook salmon, killed from a disease outbreak triggered by low and warm water flows, littered the banks and river eddies for the entire 34 miles from Grave Creek to Foster Bar. The canyon stretch of the Rogue looked and felt more like an EPA Superfund site than a Wild and Scenic river. "In every eddy, there were 10-20 dead fish," says Urie, who was accompanying her husband, river guide Bill Urie, on a June raft trip. "It looked and felt so terrible, and the stench was absolutely awful. We didn�t even get out to swim, it was so bad. "It was almost like something had been put in the river to kill all those fish," Urie says. The Rogue spring chinook could be in for a similar assault by nature this year as Southern Oregon�s midwinter drought is again threatening to kill fish. With rain and snowpack levels at 43 percent of normal, and with prospects that Lost Creek and Applegate reservoirs may not fill this year, conditions exist for the first significant chance since the early 1990s for a disease outbreak that can wipe out most of a chinook fish run. Such a disease, called columnaris, did just that in 1992 and �94, when two of every three adult spring chinook died from infections in their gills. The infections are triggered by and spread in low, warm summer flows caused by hot spring weather and drought. The real possibility of another spring drought and a hot May could create a gory repeat of dead fish in the canyon. "There�s no doubt about it," says Tom Satterthwaite, an Oregon Department of Fish and Wildlife biologist who researches the Rogue. "If we have very warm conditions in the spring, a significant part of this year�s run will be at risk to columnaris." But this year, ODFW biologists and U.S. Army Corps of Engineers hydrologists are better prepared to fight off a columnaris outbreak in the canyon, Satterthwaite says. The two agencies later this spring will start working on water-release plans for Lost Creek and Applegate lakes that will make saving the spring chinook top priority. But whether there is enough stored water in the two Corps reservoirs to save the salmon won�t be known until April. Columnaris always has been a problem in the Rogue. It is a virus that blooms naturally during warm and low river flows and suffocates chinook salmon by attacking the fishes� gills. For some reason, it seems to hit chinook the hardest. It does not target mammals or people. Columnaris usually breaks out when river temperatures eclipse 68 degrees, but not always. Yet when it does, the columnaris spreads like a plague through the water, leaving thousands of dead fish in its wake. It�s an astounding feat of destruction to witness, Urie says. Everywhere she looked that spring in �92, there were dead salmon. But almost more devastating was seeing the live ones, nosed into the cool tributary waters in futile defiance of their fate. "They were just laying there, waiting to die," Urie says. "It was terrible." Higher, cooler river flows boosted by reservoir water are the best tonic for staving off a columnaris outbreak. But once one starts, it�s virtually impossible to reverse, so an outbreak early in a chinook run can lead to a massive die-off. Using river-flow data for the Rogue Canyon area and predicted air temperatures during the summer months, the ODFW has crafted a computer model that predicts what biologists can expect in chinook mortality. Biologists and corps hydrologists use it to set water releases out of Lost Creek Lake to minimize disease outbreaks. The critical period for spring chinook is May and early June as the fish are migrating through the Lower Rogue Canyon en route to the cool waters of the upper Rogue. In most years, the best way to prevent a columnaris outbreak in the canyon is to keep flows around 3,800 cubic feet per second at Agness, which is just downstream of the canyon. That might be very tough to do this year, if natural runoff into the Rogue is low and there isn�t enough water stored in Lost Creek Lake to offset it. That�s where the ODFW computer model really comes in handy. The model, Satterthwaite says, gives biologists better tools for heading off an outbreak than they had in 1992. Mainly, they know that holding back a large chunk of water for release when the first signs of columnaris surface does not work, he says. "We know that, if you get to that point, you�re just too late," Satterthwaite says. So a likely scenario is to juggle Lost Creek Lake releases based on air temperatures to ensure, as closely as possible, that the water in the canyon doesn�t get too columnaris-friendly. As air temperatures � which can quickly spike the Rogue�s water temperatures � increase, so do the flows. Satterthwaite says a river full of dead and floating salmon isn�t inevitable this year. In fact, the pre-season concerns are less severe than those of �92 and �94. The best solution is having the local weathermen be unpopular this spring and forecast delays in the start of summer. "There are years where we have wet, cool springs," Satterthwaite says. "That would sure help. (Staff writer Mark Freeman covers the outdoors for the Mail Tribune. 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