In response to the Oregon Spotted Frog being listed as an endangered species, more water is being released into the upper Deschutes in the winter in order to provide improved overwintering habitat. At the same time, levels in Crane Prairie Reservoir are being more stably managed for consistent habitat. As a result, levels in Wickiup Reservoir should see larger draw downs in the winter which in turn will likely negatively impact its fish population. As a result, ODFW is changing the regulations for Wickiup to reduce the number of kokanee that may be harvested.
At a recent meeting describing these changes ODFW explained that there is no fish screen at the Wickiup discharge and significant numbers of fish pass into the Deschutes. This includes well over a million kokanee in some years. Kokanee are landlocked sockeye salmon and are not native to the upper Deschutes. For many years they were planted in Wickiup and Crane Prairie, a practice that was discontinued in 1986 and 2009 respectively. Kokanee can reproduce in fresh water lakes and rivers, however, and they continue to be present in both reservoirs.
Even after many generations of residing in lakes, kokanee retain sockeye genetics and continue to desire to migrate to the ocean, hence the large numbers that migrate down the Deschutes. Some are successful. Each fish in the most recent sockeye run to return to the Pelton Round Butte trap on the lower Deschutes was genetically sampled. Of the 484 fish that were captured, 18 (4%) were upper Deschutes origin, meaning they came from Wickiup or Crane Prairie Reservoirs.
I find this astonishing. When only about 4 inches long, these fish moved down the Deschutes, over Benham Falls, Dillon Falls, and Big Falls, through the Selective Water Withdrawal facility in Lake Billy Chinook, out to and down the Columbia, through its dams, out to the ocean, and then came back! What was equally amazing were the pictures of some of the adult kokanee that have been caught at Wickiup over the past few years. I may have to learn how to fish for them.