1M salmon stocked in Lake Granby
Grand County, Colorado
It takes careful management by the state's wildlife agency to maintain the ecosystems that allow vast populations of nonnative species to thrive.
As part of that mission, officials from Colorado Parks and Wildlife last week released roughly one million kokanee salmon frie, the term for baby fish smaller than fingerlings, into the Colorado River just below Shadow Mountain Dam.
The fish will spend their lives in Lake Granby and, assuming larger fish do not eat them, they will return to the exact riverbank where they were released to spawn in three to five years.
The release is part of a decades-old fisheries project conducted by the state to provide quality sport fishing opportunities, a prey base for larger predatory fish, and a source of future kokanee eggs.
The release was one of several Colorado Parks and Wildlife officials have made in Grand County this year, with the release below Shadow Mountain Dam being the single largest release in Grand County.
Kokanee frie are also released into Shadow Mountain Lake above the dam, Willow Creek Reservoir, Grand Lake, Williams Fork and Wolford Reservoir. The other release totals vary with a low of about 30,000 released in Willow Creek and a high of 350,000 released into Williams Fork. Kokanee eggs are harvested each fall as the fish entering their spawning season.
The selection of kokanee as a stock fish is no accident.
Kokanee are well adapted to the local reservoirs, according to CPW Aquatic Biologist for Middle Park Jon Ewert.
"Our lakes fluctuate, because they are storage reservoirs. That is not a normal condition most fish are well adapted for," Ewert said. "Kokanee are open water filter feeders. They don't care how deep the water is, they don't use or relate to physical structures. They feed on zooplankton in open water."
Ewert noted that the choice of kokanee as a stocking fish is based on several parameters.
Kokanee are quality sport fish providing both a challenging angling experience and a quality food product after the catch.
"Kokanee are very tasty to eat," Ewert said. "They have really rich pink meat that is nice and oily."
Ewert also noted the selection is based on the kokanee's feeding patterns, since they are filter feeders and do not hunt and eat other sport fish in the lakes. As such, they do not compete with other fish like lake trout and instead serve as their main food source.
"There are 40-inch long trophy lake trout out there," Ewert said. "What produces that is a good healthy base of kokanee salmon."
While officials like Ewert are happy to have other fish feed off the kokanee, they also hope enough survive to maturity to help sustain the state's egg harvesting efforts.
In the 1970s and 80s, Lake Granby was the only source of kokanee eggs in the state, but as the program has expanded Blue Mesa Reservoir has become the primary source for kokanee eggs.
Ewert explained kokanee salmon are a unique evolutionary breed originally from the Pacific Northwest that developed as an entirely landlocked species.
"Genetically they are the same thing as sockeye salmon," Ewert said. "They are just the landlocked form."
Lake Granby was the first water body in Colorado to see the introduction of kokanee salmon. The fish were stocked for the first time in 1951, shortly after the reservoir was initially filled. The salmon were taken from Flathead Lake in Montana and brought to Colorado for the project.
Since then the program has expanded and includes reservoirs throughout the state. The egg harvesting work done by CPW takes place during the fall spawning season. Eggs are collected and taken to the State Fish Hatchery in Glenwood Springs where they are cared for until they are ready for release in the spring. According to Ewert, roughly 80 percent of the hatchery's eggs survive to spring release.
Funding for the state's kokanee program is provided almost entirely through angling license dollars, according to Ewert, with some additional funding coming from the federal government through taxes on sporting goods sales.