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Habitat degradation:
Habitat degradation:
- Dams and irrigation canals
- Bank armoring
- High temperatures in downstream reaches
- Invasive species
Restoration action:
- Supplementation in 1997
- Acclimation facilities to extend spawning distribution
Notes:
The Yakima is one of the most productive agricultural valley in the US, most famous for wines, cherries, apples, and peaches.
A supplementation facility located in Cle Elum, WA began operating in 1997. Its explicit purpose is to increase natural spawning.
Juvenile chinook are reared at the hatchery or at one of 3 acclimation facilities: one in the upper Yakima, one downstream of the hatchery, and one in the Teanaway River.
The purpose of these acclimation facilities is to house juveniles during imprinting so they may return to the vicinity as adults for spawning, thus expanding the spawning distribution.
Research has shown an increase in redd counts due to supplementation, but no increase in parr production. Density dependence is a major factor resulting in limited success. Are hatchery produced fish building inferior redds? Are their offspring less able to compete?