CPW to introduce sterile walleye at Ridgway Reservoir

John Livingston
Southwest Region Public Information Officer
970-759-9590 / [email protected]
@CPW_SW

RIDGWAY, Colo. – Walleye are coming soon to Ridgway Reservoir.

After years of coordination, Colorado Parks and Wildlife aims to stock sterile walleye into the reservoir at Ridgway State Park during the spring of 2024.

“This is part of a larger goal to increase angling opportunities in western Colorado in a way that is compatible with the native species of the Upper Colorado River Basin,” said CPW aquatic biologist Eric Gardunio. “This will diversify the fishery while still allowing us to maintain and accomplish other management goals within the reservoir.

“The goal is to sustain a robust forage base and to maintain reproduction and recruitment for brown trout so that we will have two quality, top-end predatory fish species in Ridgway for anglers to fish for.”

CPW aims to begin stocking sterile fingerling walleye into the reservoir this spring. The fish will be spawned and undergo the sterilization process at Pueblo Reservoir before being transferred to the Pueblo State Fish Hatchery.

“Using these sterile walleye really allows us to diversify our fishing opportunities,” said CPW Area Wildlife Manager Rachel Sralla. “We are excited to add this new species to the fishery, and we look forward to developing and maintaining this population over the coming years to provide opportunity for multiple angling interests.”

In order to stock a new species in western Colorado waters, CPW must write a Lake Management Plan that outlines the management strategy for a given fishery. The plans are vetted through local CPW staff and then approved by partner agencies, including the U.S. Fish and Wildlife Service and state fisheries programs from Utah and Wyoming. 

For Ridgway Reservoir, two key stipulations of the plan were to stock only sterile walleye and to construct an escapement barrier on the spillway that further prevents escapement of sterile walleye and smallmouth bass into downstream waters.

The fish escapement barrier was constructed on the spillway at Ridgway Reservoir by the Upper Colorado River Endangered Fish Recovery Program and partners. That included CPW, the Colorado Water Conservation Board, Tri-County Water and the Bureau of Reclamation.

CPW produces millions of sterile walleye fry each year. These fish offer managers a unique opportunity to create novel fisheries in waters where reproduction would be problematic. They also allow managers to have a greater ability to fine tune fisheries because their numbers can be driven by stocking rates.

Ridgway Reservoir, a 1,000 surface-acre reservoir, will receive 30,000 1.2-inch long walleye fingerlings annually beginning in May, provided successful sterilization is achieved. This is a relatively low stocking rate when compared to other walleye fisheries in the state.

“We want to start slow with our stocking to make sure that we are maintaining the forage base and we can monitor effects on other components of the fishery,” Gardunio said. “Having sterile walleye available for stocking allows us to maintain the prey species in Ridgway Reservoir, providing the energetic base to grow large predatory species that many anglers are looking to catch. By controlling our stocking rates, we can also accomplish other management goals such as maintaining the trophy brown trout fishery that currently exists.”

Ridgway Reservoir has abundant populations of white suckers, yellow perch, smallmouth bass and crayfish. The juveniles of these species offer a robust food resource for species such as sterile walleye. When appropriate stocking rates are utilized, those prey sources should be sustainable into the future. The walleye will also help CPW with management of the smallmouth bass.

“The illegal introduction of smallmouth bass really hurt our fishery and prevented us from doing some things,” Ridgway State Park Manager Johnathan Freeborn said. “We looked at numerous ways to mitigate those issues and chose the smallmouth bass harvest incentive tournament that has been pivotal in our management. Through the success of that tournament, we are now able to look at doing something like introducing walleye.”

General harvest regulations will be in place for walleye at Ridgway Reservoir allowing anglers to keep five fish daily.  Anglers harvesting walleye or perch should be sure to know how to correctly identify the two species prior to keeping a fish. While walleye anglers will be eager for this new opportunity, they should be patient as the fishery develops.

“We expect it to take three to five years for the first stocked walleye to reach 14 to 16 inches in Ridgway Reservoir,” Gardunio said. “Ridgway walleye should grow efficiently by eating the suckers, perch, smallmouth and crayfish. I would be surprised if we don’t end up with some 30-inch fish, but it may take more than 10 years to see that size fish. Once the fish are stocked as fingerlings, anglers should start catching them.”

Ridgway State Park is already looking forward to hosting anglers to pursue the sport fish.

“Walleye fishing is addictive,” said Freeborn. “Walleye fishermen travel the country to fish for walleye. We look forward to a future where our park becomes a desirable walleye fishery along with still providing opportunities for trophy brown trout and rainbow trout.”

Diversifying Fisheries Across Western Colorado

The addition of sterile walleye into Ridgway Reservoir is the latest step CPW has taken to provide diverse opportunities for anglers in western Colorado.

A Lake Management Plan for Sweitzer Lake State Park has allowed CPW to start stocking largemouth bass and bluegill at that reservoir in Delta with the goal of creating a quality warm water fishery.

CPW has added more than 200 habitat structures to Sweitzer Lake, Crawford Reservoir and Confluence Lake to improve the quality of those fisheries. Aquatic biologists have also creatively managed for unique species such as tiger trout and grayling in several high mountain lakes.

“CPW’s mission is to provide recreational opportunities while maintaining the wildlife resources of the state of Colorado,” Gardunio said. “We’ve heard from our local anglers that they want more warm water fishing opportunities and diverse species, and we are trying to create that recreational opportunity in a way that is compatible with our native species conservation goals.

“I fish these waters, too, and I really like fishing these waters. I’m as excited about these opportunities as a lot of other people.”
 
Ridgway State Park, located about 20 miles south of Montrose in southwest Colorado, is one of the state’s most beautiful parks. For more information about the park and to make camping reservations, go to: http://cpw.state.co.us/placestogo/parks/Ridgway/Pages/default.aspx The fish escapement barrier on the spillway at Ridgway Reservoir.