â… these savages have willows on the other side of this little river (Walla Walla) where they catch large quantities of salmon trout, suckers, & Câ
– April 29, 1806, John Ordway, a US Army sergeant who volunteered to join Lewis and Clark on their voyage of discovery in the Pacific Ocean.
Pound for pound, no freshwater fish fights harder than a rainbow trout. They swim faster and jump higher than their cousins ââthe Pacific salmon. Some have the ability to migrate over 2,000 miles to the ocean and come back, breed, and survive all obstacles to start over.
No wonder these iconic fish are the favorites of many anglers.
Genetic evidence in the 1980s led to placing the rainbow trout (also known as the rainbow trout when it spends its entire life in freshwater) in the genus Oncorhynchus, along with the trout cutthroat and the five species of Pacific salmon.
The larger group dates back 18 million years, with only a few central populations surviving the last glacial maximum that occurred about 20,000 years ago. Descendants of Ice Age refuges eventually colonized various habitats that include lakes, rivers, estuaries, and tiny mountain streams.
During their arduous journey on the Columbia River, Expedition members Lewis and Clark coined the term “salmon trout” to refer to rainbow trout, perhaps with trout encounters in mind. upstream and migrating salmon.
It is believed that a million or more rainbow trout entered the Columbia River before the arrival of European American settlers. Harvested commercially in North America until the 1930s, reported catches reached 5 million pounds in 1892.
Population Decline Fast forward a century later to a landmark study by a team of scientists that reported that 75 separate stocks of West Coast rainbow trout were in danger of extinction. The alarm bells went off.
A follow-up review conducted by the National Marine Fisheries Service in 1996 concluded that the Upper Columbia River Evolutionary Significant Unit was in danger of extinction. The majority of the SEU stocks in central Colombia (ie the Yakima, Walla Walla, Umatilla, John Day and Deschutes rivers) were “in decline”. Rainbow trout in the Snake River Basin ESU were considered to be at risk “for the foreseeable future”.
Like salmon, artificial propagation was seen as a way to counter the effects of loss and degradation of spawning and rearing habitat and overexploitation of wild populations. Unfortunately, the releases of large numbers of hatchery rainbow trout masked the decline of wild fish and in some cases resulted in negative genetic effects including reduced reproductive success.
Perhaps more critical is that nearly 50% of the once available riverine habitat has been blocked by dams, culverts and irrigation diversions.
Warning readers in 1898, the Weston Leader reported that Pine and Dry creeks, once excellent trout creeks, “have been blocked for several years.” A comprehensive study of the Columbia Basin streams by the Fish and Wildlife Service in 1950 documented more than 150 diversion dams on the Yakima River and its tributaries. A lack of water in the lower Umatilla River during fish migration has also been reported. On the Walla Walla River below Milton-Freewater, the river bed was dry for 2.5 miles from late spring through summer.
Recognizing the importance of waterways to the survival of rainbow trout, regional fisheries management agencies promulgated new trout harvesting regulations that included a minimum size of 8 inches and an opening of season in late May to allow more young rainbow trout or “smolt” to exit safely. âTake-outâ rainbow trout plantations are currently limited to lakes and the adult rainbow trout harvest is largely limited to hatchery fish.
Restoration of Rainbow Trout Routes A wide range of activities are underway to strengthen Rainbow Trout routes to tributaries of the Columbia River.
Portland General Electric and the Confederate Tribes of Warm Springs have teamed up to reintroduce salmon and rainbow trout upstream from the Pelton-Round Butte dam complex on the Deschutes River. Confederate tribes from the Umatilla Indian Reservation recently released adult rainbow trout equipped with radio transmitters into the McKay Reservoir to help solve unknowns associated with the reintroduction of rainbow trout to habitat. spawning and breeding equipment not used for nearly a century.
Over the past two decades, conservation groups that include the Walla Walla County Conservation District, the Natural Resource Conservation Service, Tri-State Steelheaders and others have removed diversion dams, restored riparian corridors. and wetlands, placed large woody debris and identified conservation easements in local waterways. .
Recent work to improve passage of adult rainbow trout and salmon through the flood control channel of the urban town of Walla Walla provides access to high quality spawning and rearing habitat at the top of Mill Creek.
On a larger scale, the Western Rivers Conservancy (WesternRivers.org) focuses on land acquisition and habitat improvement activities in the John Day, Methow, and other western rivers. The goal is to protect the upstream tributaries where Rainbow Trout spawn and thrive by partnering with long-term stewards, including land management agencies and tribes.
What does the future hold for us? The life cycle of the rainbow trout is fraught with pitfalls.
Obstacles to the safe downstream passage of juveniles through the main dams of the Columbia and Snake rivers include predators (p. Ocean life is also a challenge. Steelhead spends 15 to 30 months of its life in the Pacific Ocean avoiding foreign nets, the “Blob” (hot water heating the ocean), killer whales, microplastics, sewage and industrial waste.
If that’s not enough, the rivers in the Northwest seem to heat up sooner and stay warmer longer. Cold-water tributaries that enter the lower Columbia River provide temporary refuge for rainbow trout migrating upstream when summer temperatures are high, but overall survival is not higher because fishermen to the line enter these areas. The Deschutes and Umatilla rivers provide the only potential sources of cold water in the 100 mile stretch between Dalles and McNary Dams.
The number of adult rainbow trout passing the Bonneville Dam has averaged close to 200,000 to 300,000 fish over the past 40 years. In 2001, a record 630,000 passed, 75% of which were hatchery origin. The forecast for 2021 calls for a return of approximately 89,200 A-fish (one-salt fish) and 7,600 B-fish (two-salt fish) mainly to production areas in the Snake River Basin.
According to fisheries managers, âthis is the second worst rainbow trout run since 1938â.
Time is running out for âsalmon trout,â but there is hope for their survival through the combined efforts of resource management agencies, conservation groups and private landowners. Saving rainbow trout for future generations requires not only more efficient use of water, but also better management of our rivers and streams.
Dennis Dauble is the author of four books on fish and fishing, including the award-winning âFishes of the Columbia Basinâ and âBury Me With My Fly Rodâ. His website is DennisDaubleBooks.com.