Steamboat Springs A biologist for the Colorado Division of Wildlife expressed cautious optimism Wednesday that the trout in the town section of the Yampa River will survive this summer's drought.
Fisheries biologist Kevin Rogers, who is based in Steamboat Springs, would not have said the same thing a couple of months ago.
"I hope that the worst is behind us," Rogers said. "I'm much more optimistic than I was earlier in the summer. I was reasonably certain back in June, that we were going to lose the fishery."
Rogers said he's aware that some local anglers are getting restless and eager to resume fishing. His agency is monitoring the status of the fish carefully. But for now, the voluntary ban on fishing remains in place from the Chuck Lewis Wildlife Area (upstream from Steamboat), downstream to the confluence with the Elk River.
The reversal of Rogers' outlook on the fate of the fish can be attributed to rain, cooler temperatures and the slightly higher oxygen content that comes with colder water.
The flow in the Yampa at the Fifth Street Bridge measured 51 CFS at 1:15 p.m. Wednesday and the water temperature was 67.1 degrees. Prior to the latest round of monsoon moisture this week, the temperature of the river was peaking in the mid-70s. But the return of cooler temperatures has boosted dissolved oxygen content above 4 parts per million, a critical threshold for trout.
Rogers found acceptable dissolved oxygen levels at the Lewis Wildlife Area, the Tree Haus Bridge and at the confluence of Fish Creek on Monday. Storm Mountain Ranch paid for the installation of an aerator at Fish Creek several weeks ago.
Earlier this summer, the water temperature had crested at 80 degrees, a level that is potentially lethal to trout, because the warmer water can't contain sufficient oxygen. Rogers said he was impressed with the ability of the trout in the Yampa to withstand those conditions.
"They proved to be more resilient than we thought," Rogers said. "We lost a handful of whitefish back when the water temperatures were reaching 80 degrees. When you look back at the numbers, you still wonder how we didn't lose this thing, because it was ugly for a long time."
Rogers said the trout aren't out of hot water just yet. They still face the likelihood of low flows and prevailing high-pressure system in September. But nighttime temperatures can also be expected to drop.
Low flows in winter are also a challenge, but the fish should be able to congregate and survive in the deepest holes in the river.
The question remains whether the region's reservoirs will refill next spring, affording more water to replenish the rivers.
"We need a heavy snowfall this winter," Rogers said.