Tuesday, February 02, 2010
Hatchery Program Threatens Native McKenzie Redsides
The ISFAC was formed last year to help ODFW implement its 25-year Angling Enhancement Plan. The Native Fish Society and Trout Unlimited helped author this plan, and even though the final version is much better than the original drafts, some ODFW staff members are trying to use this plan as an excuse to increase hatchery stockings and harvest on wild fish.
The McKenzie River is a prime example. Roughly 98 percent of Oregon's flowing water is managed for wild trout; however, the McKenzie still has a significant trout stocking program, and native McKenzie redside rainbow trout are threatened by these hatchery fish.
For nearly 100 years, the McKenzie's native redside populations have been depressed, often by the very agencies we've appointed to protect them.
Oregon started planting hatchery rainbows in the McKenzie River in 1921, and hasn't let up since. By 1947, the wild fish population in the McKenzie was already reduced. According to creel surveys, 45% of the fish caught in those years were hatchery fish.
ODFW stocks the McKenzie River from Blue River to around Hendricks Bridge with 113,000 fish. Hatchery trout are introduced to the system almost every week in the prime growing season for wild fish. This competition for food and constant angler pressure for hatchery trout has depressed the wild population of redside trout in 38 miles of river.
There is a consensus in the scientific community that in general, hatchery fish harm native fish populations. Jeff Ziller, South Willamette Watershed District Fish Biologist has called this section of river a sacrifice zone. ODFW and Army Corps of Engineers biologists suspect from observational evidence that the depression of wild rainbow trout populations in the planted zone is substantial, or even severe.
There are several examples of rivers with wild trout populations that have rebounded quickly after stocking hatchery trout was ceased, including Oregon's Metolius and Deschutes Rivers -- and studies on the Lower McKenzie River when ODFW ended stocking in that section of river.