Saturday, October 19, 2002
A group of 13 fishermen netted more than 350 trout from a short stretch of the Yampa River south of here Friday morning. And if you're thinking they might have been cheating, you are correct in that analysis.
The anglers weren't fishing in the traditional sense of the word; instead they were assisting personnel from the Colorado Division of Wildlife, who were taking a census of the river below Stagecoach Reservoir. Because fish often express reluctance to swim up and introduce themselves, the volunteers were using electro-shocking devices to make the fish easy to net.
Later, the trout were measured and weighed, then returned to the water.
Plenty of fat 18-inch trout were netted from a 280-foot section of stream. But DOW fisheries biologist Kevin Rogers was most excited about the smallest trout recorded in the survey.
"I'm hoping today that we'll confirm what we found six weeks ago. We had strong recruitment of juvenile rainbows this year. Sometimes in drought years you actually get better recruitment because the water is warmer and the fish put on more weight before they go into the winter."
He was rewarded with a high number of juvenile trout.
Rogers pointed out the Upper Yampa Conservancy District came to the aid of the trout during spawning season. When the biologist asked that additional water be released to cover the gravel in the spawning redds, reservoir managers complied. That action probably saved this year's juvenile trout, Rogers said.
Electro-shocking is a way to gather baseline data about the fish population in a finite stretch of stream year after year. The information gathered is used both to make management decisions and measure the effectiveness of those decisions, Rogers said.
The electro-shocking device itself produces 350 volts of pulsing direct current. It is applied by men and women in waders walking upstream. They carry long poles with metal hoops on the business end in one hand. In their other hand, they carry long-handled nets. A half dozen of the poles fixed with hoops are linked together by a heavy electrical cord which leads to the generator.
The electrical current poses no danger to the wader-clad volunteers, although they are cautioned against plunging their hands into the water, lest they feel a shock.
The trout experience muscle spasms that bring them to the surface and render them unable to flee as a result of the pulsing current.
"If you get it set just right, they'll swim right into your net," Rogers said.
The crews carrying the shocking poles are backed up by more volunteers carrying nets and hauling a couple of small boats or "live cars" against the current. They made two passes on the short section of river to ensure they netted as many fish as possible.
Every fish, trout or not, no matter how small, is netted and inventoried. The actual netting becomes a competition among the volunteers, with those who net heavy rainbows earning bragging rights over those who bag small whitefish and sculpins. Rogers is right in the thick of it, lunging to "steal" a fish from the guy next to him and teasing his victim.
A handful off fish don't survive electro-shocking, but the data is essential to understanding what is happening in the trout population.
Rogers said it would be a mistake to assume the roughly 350 rainbows plus varying numbers of other species represented the total population in that stretch. He will measure the difference between the fish netted in the first pass and those netted in the second pass. Next, he'll use those numbers in a model that extrapolates an estimate of the total fish population.
The tailwater fishery below Stagecoach, part of Stagecoach State Park, is barely three-quarters of a mile long, but it has gained regional notoriety for the sheer numbers of fat rainbow trout that swim in the currents.
In this era of whirling disease, Rogers said, it is rare to see a rainbow fishery in Colorado with such successful spawning and recruitment of juvenile trout.