
Next time you catch a walleye at a Colorado state park, thank an aquatic biologist for putting that fish there in the first place. Walleye production is a major process involving enforcement, biologists, state parks and hatcheries working together to produce great angling opportunities.
It starts with the walleye spawn, which is taking place now at Chatfield, Cherry Creek and Lake Pueblo state parks. On a recent Friday during the spawn at Chatfield, Colorado Parks and Wildlife Aquatic Biologist Paul Winkle led a team of biologists and volunteers through a half-day process that included collecting male and female walleye, fertilizing the eggs and microchipping the females before releasing them back into the lake. This process will eventually contribute 3 million walleye fry at ¼- inch in length to Chatfield Reservoir, a popular spot for local angling.
“Walleyes are not native to Colorado, and they were first imported to Colorado in the early 70s. There are a couple reservoirs such as Carter and Horsetooth in Colorado where walleyes reproduce successfully enough they can sustain their populations without any help, but those are the exceptions,” Winkle recently told the Terry Wickstrom Outdoors radio show. “The reason why is walleye eggs sink and they become sticky and stick to rocks on the bottom to incubate and eventually hatch. Places like Carter and Horsetooth have a lot of rocks on the bottom. Places like Chatfield and Cherry Creek are more sandy-bottomed. A lot of the eggs get covered up by the silt and get smothered.”


That’s why CPW, working cooperatively with organizations such as the Colorado Walleye Association, help the process along. Walleye fishing contributes millions of dollars in economic impact and the walleye collectively produced by CPW and other partners are valued at $3.2 million. Statewide, CPW stocks 90 million fish annually into waters throughout Colorado in order to ensure good angling opportunities.
“We set up gill nets along the dam at Chatfield and Cherry Creek reservoirs, typically about 50 to 100 feet out from the dams, along the whole length of the dams. Then we go out the next morning and pick fish out of those nets,” Winkle said. That’s why for about a month every spring, anglers cannot fish from the dam at those reservoirs. The team typically handles up to 1200 fish during the approximately two week spawn period.
The other half of the spawning process takes place at the Chatfield Marina. The walleye collected from the nets are checked by hand for “ripeness,” meaning whether they are ready to be milked for eggs. The “milking” happens by hand as well, typically at a rate of 32-40 per day. These eggs are then combined — again, by hand, using goose feathers to stir gently — with male sperm, or milt. Sometimes sauger sperm, traded from Nebraska in exchange for walleye eggs, is used in order to create a saugeye hybrid. Saugeye, which are more active in shallow water, are ideal for fishing close to shore at the reservoir. The decision to create hybrids is part of CPW’s commitment to cultivate excellent angling opportunities in Colorado.

The biologists also inject a microchip into the adult female walleye before releasing them back into the lake. This helps CPW track the growth, productivity and survival of the walleye during future spawning cycles. This in turn makes the spawning process more efficient and economically viable. CPW does not receive general tax dollars and fishing license fees support all statewide hatchery and fish-stocking operations.
The 2017 annual fishing license is good starting April 1, so buy yours now to take advantage of the range of options CPW offers anglers, from the annual fishing license to the one-day fishing license as well as educational opportunities for those new to angling. Buy a license online on CPW’s website or by phone at 1-800-244-5613.
Photos and story by Alicia Cohn. Cohn is a former communications specialist for CPW.