Fisheries

Drought in West Puts Fisheries in Hot Water
Enn.com, July 31, 2000

The hot, dry summer will impact fly fisherman such as Larry Larsen, here trying his luck on the South Fork of the Snake River in Idaho. The heat is on. Wild fish and avid anglers are beginning to feel the effects of this summer's drought in Idaho, Wyoming and Montana. "Lack of water is always a problem for fish," said Kathy Buchner, director of the Wyoming Council of Trout Unlimited. "We are concerned that the drought might add to the problems endangered fish currently face such as habitat degradation and invasive species." Two counties in Wyoming and three in Idaho have declared drought emergencies. About half of Montana's major river stretches are rated moderately to extremely dry. "Fish are undoubtedly beginning to feel the stress caused by low flows, higher water temperatures and competition for space and food," said Larry Peterman, Montana Fish, Wildlife and Parks fisheries division administrator. "Low water conditions in spring and fall can cause spawning failures and increased predation on young fish can impact adult trout numbers in future years. If conditions worsen, we will most likely lose fish to stress from the increased water temperature and decreased oxygen available."

Peterman estimates that a wild trout population seriously impacted by drought may take three years or more to recover. All species, native and resident, will be affected in the state of Idaho, said Tom Rogers, fisheries hatchery supervisor for the Idaho Department of Fish and Game. "As temperatures rise, there are more algae blooms due to nutrient concentration, which decreases the amount of oxygen available in the water," he explained. Especially sensitive to warmer conditions are cold-water species such as rainbow trout and the threatened bull trout. In response to the drought, Rogers said his department is likely to cut back on stocking areas that have lethal water temperatures. If the situation worsens, the department may liberalize fishing limits in areas where the fish are not likely to survive. For species at risk such as the bull trout, which is listed as a threatened species, wildlife officials may salvage surviving fish and relocate them. "The fish are getting really hammered," said Jerry Eder, the manager of Silver Creek Outfitters in Ketchum, Idaho. "They are less aggressive because they are not eating as much." Rainbow trout are especially sensitive to temperature, preferring cold water. Warm water speeds up metabolism, yet more effort is required for the fish to find food, he explained. Their energy is depleted even when they are caught by an angler.

"Fishing is a major part of this economy," Eder noted. "The last few seasons we have seen more pressure on the resources. August is the hottest month of the year and there is talk of closing certain fisheries. I would encourage people to fish in the early morning and early evening." In Montana, fisheries biologists have asked anglers to reduce voluntarily the amount of pressure they place on fisheries. Other recommendations they offer to minimize stress include landing fish quickly once they are hooked, keeping fish in the water as much as possible when handling them, and avoiding contact with the fish's gills. The drying of water sources for irrigation is also expected to have an impact on fisheries. "When you have competition between irrigators who need water for crops and the need for water in streams for fisheries, one side is going to lose," said Dick Larsen of the Idaho Department of Water Resources.