Cutthroat trout stage comeback on Hoback
After years of stocking, Game and Fish find wild natives survive winter better, grow larger.
Fisheries Technician Julie Begin, with the Wyoming Game and Fish Department, nets a fish Friday while electrofishing on the Hoback River. Researchers are finding more — and bigger — cutthroat in the river this summer. JACLYN BOROWSKI / NEWS&GUIDE View our entire photo gallery >>
By Mike Koshmrl, Jackson Hole, Wyo.
July 11, 2012
The Hoback River’s cutthroat fishery has bounced back, now that the Wyoming Game and Fish Department has stopped stocking it with hatchery-raised fish.
For years, the Hoback was a “put and take” river stocked with 4- to 6-inch fry that had very little wild reproduction, Game and Fish spokesman Mark Gocke said. The waterway, along with a multitude of other rivers around Wyoming, was slowly weaned off stocked trout during the 1990s and early 2000s.
“They changed management to focus on wild, naturally reproducing Snake River cutthroat trout,” Gocke said.
Since the agency discontinued Hoback’s stocking program in 2005, biologists have observed a spike in native Snake River cutthroat populations.
Game and Fish initially changed strategies because the hatchery-raised cutthroat weren’t making it through the winter, and stocking was proving a lost and costly cause.
The 55-mile-long Snake River tributary is shallow, fast-moving and notorious for build-ups of frazil ice that can be deadly for fish, fishery biologist Diana Miller said.
The agency had a hunch that wild fish would be better suited to the harsh winters, Miller said.
“Population estimates previous to  had a lot of stocked trout in them,” she said before departing on a recent electrofishing survey. “Now we don’t ever see hatchery fish, and our population numbers are just as good as they were prior to when we were stocking.”
The numbers tell the story.
From 2000 to 2005, Game and Fish biologists stunned, weighed and measured an average of 565 cutthroat in the section of the river stretching from Hoback Campground to Stinking Springs.
Between 2006 and 2011, the average jumped to 834.
Data for 2012 from the historically surveyed section are not yet available, but an upstream section of the river produced strong numbers this summer.
The Hoback’s cutthroat are not only increasing in number, they are bigger, as well.
“The size structure is better because we get new recruitment,” Miller said. “Those hatchery fish weren’t spawning. They were just eating the food that the wild fish would have been eating, and then they were dying.”
Amperage from two sets of electrodes that dangled off Miller’s raft stunned two dandy cutthroat specimens within seconds of her putting on the river during the July 2 electrofishing outing.
A colleague snatched up two Snake River cutties, a 9- and 13.2-inch fish, in a dip net, and another jotted down their species and size for Game and Fish records.
A creel study conducted on the Hoback last year showed that anglers are reaping the benefit. Game and Fish’s management catch-rate objective for wild fisheries is about a fish every two hours. The Hoback came in at almost two fish an hour.
Improvements aside, because of its fast flows and ice conditions, the Hoback might never be a top-tier trout fishery, Miller said.
“On the whole, we had catch rates that were much higher than our objectives,” she said.
“We see people who do super well,” Miller said. “And then we see people who fish their little hearts out and don’t catch fish.”