Blues in the Genes

The Salmonid Situation on the Lower Deschutes

Salmonids are exquisitely adapted to local stream environments. The genes of a wild Pacific salmon are unique to the specific stream in which they evolved. A spring chinook from Loon Creek, a tributary of the Middle Fork Salmon River in central Idaho, is genetically distinct from a springer born in Big Creek, another Middle Fork trib just downstream of Loon. 

Over thousands of years, salmon adapted to the dynamic landscapes of the west slope of the North American continent. Relatively rapid adaptation to a broad range of conditions allowed these species to flourish amid the calamities of flood, drought, fires, ice ages, landslides, and volcanic eruptions. Salmonid survival strategy is to thrive amidst chaos.

In 1980, when Mt. St. Helens blew its top, fisheries biologists assessed the damage to in-stream habitat on the Toutle River and declared the system dead for trout, salmon and steelhead for generations to come. But steelhead didn’t get the memo: in 1983, the largest run of wild winter steelhead in the state of Washington was on the Toutle. 

Though wild salmon genes are incredibly resilient, elastic, and adaptable, they are less so when crossed with salmon born and bred in hatcheries. Research done in the 1990’s on the Hood River, and since confirmed in many other river systems, shows that genetic fitness declines when wild fish interbreed with hatchery fish. The implications of these findings should require hatcheries, no matter their stated goal or purpose, to proceed with utmost caution. Unfortunately on the Deschutes, with Portland General Electric’s efforts to reintroduce salmon and steelhead above the Pelton Round Butte Complex,  this hasn’t been the case.

Contrary to information you might glean from PGE, the now 14-year long struggle to put anadromous fish above three dams on the Deschutes is entirely hatchery based, and entirely non-volitional. The latter term means that fish are collected as adults at the Pelton trap below the re-regulating dam, or as juveniles in the forebay of Lake Billy Chinook. In both portions of their life cycle stage, these fish get a truck rideride in a truck to circumvent the otherwise impassible dams. 

Steelhead reintroduced above the Pelton-Round Butte Project originate at the Round Butte Hatchery. In the years leading up to the advent of the Selective Water Withdrawal Tower and reintroduction, hatchery steelhead were planted upstream of the dams. The hope was to jump-start reintroduction by acclimatizing juveniles to some fairly pristine spawning and rearing habitat. Anyone who had the chance to fish Whychus Creek–particularly near its confluence with the Deschutes, about 5 miles above where the fetid slackwater of Lake Billy Chinook begins–will recall the wiley, beautiful redband trout and their slashing, strong, confident rise to a fly through some of the coolest, cleanest water in the basin. Unfortunately for these fish, hatchery steelhead were planted here, and rather than swim through the reservoir to catch a truck downstream, they residualized in Whychus Creek. (Can’t blame them for choosing better habitat). As the DRA first reported in 2018, the unique genetic legacy of this wild strain of redband trout has been lost. The hatchery steelhead spawned with the local trout population. This is precisely the kind of unintended, uncontrolled genetic experimentation that fisheries managers know by now to avoid. 

As the DRA reported recently, spring chinook in the lower Deschutes River are dwindling in numbers at a rate that should prompt concerns about extinction. C. shasta, is a parasite that has blossomed in the Deschutes since warm, polluted water from the surface of Lake Billy Chinook started being sent downstream in 2010. Hatcheries breed not only fish, but the diseases that kill them. This raises another problem of hatchery-based salmon recovery: hatchery fish are treated with antibiotics. For practical reasons, wild fish are not, and this leaves them especially vulnerable to the diseases that proliferate in hatcheries. 

Since 1978, three hatcheries have provided spring chinook for the Deschutes: Round Butte State Hatchery, Warm Springs National Fish Hatchery, and Parkdale State Hatchery on the Hood River. Each hatchery has sent fish to the other over the years when production goals haven’t been met. 

The hatchery at Warm Springs has been problematic since it first opened. The Warm Springs River, as the name suggests, flows at slightly less than ideal temperatures for a hatchery operation, but this is where water for this facility comes from. Making matters worse, the rearing pens here bake all spring and summer in the high desert sun. Warm water, which produces more of the bacteria conducive to disease, has always been an issue. In addition to deadly c. shasta, fish at Warm Springs Hatchery are exposed to unusually high concentrations of the pathogens that cause Ich (Ichthyophthirius multifilis) and columnaris (flavobacterium columnare).

Outbreaks of disease at Warm Springs NFH  have at times been so intense that all its rearing fish have been moved to other hatcheries. As a 2021 report  by the U.S. Fish and Wildlife noted, the prevalence of disease is high enough that without antibiotic treatment, all fish at Warm Springs NFH would likely die. 

That report was part of a laudable effort by USFWS to look at how its fish hatcheries will fare under intensifying climate change conditions. The future at Warm Springs NFH looks daunting. Even warmer temperatures, lower river flows, and as a consequence, higher risk of disease, will make raising spring chinook here a complex, if not impossible challenge. 

The gene bank of wild salmonids in the Deschutes Basin was robbed in the 1950’s when Portland General Electric cut off access to three-quarters of the basin with construction of Pelton Dam. The subsequent failure to provide fish passage meant that genetic diversity of wild steelhead and salmon in the basin would be severely reduced. The consolation prize was supposed to be a hatchery-based, volitional fish passage system that engineers were confident would work. It didn’t. Since 2010, the consolation prize for that failure has been a non-volitional, hatchery-based reintroduction program. That isn’t working either. 

The raging debate over hatcheries–all or none–belies the reality that coping with the ravages of climate change will likely mean that hatcheries, particularly as a tool of reintroducing species from portions of rivers from which they’ve been extirpated–will be a part of future fisheries management. Nonetheless it is still true that the best hatchery will always be a healthy river system. What is happening on the river should tell us that the Deschutes isn’t healthy.  Nothing less than thousands of years of irreplaceable salmonid genetic adaptation is at stake. Once it’s gone, it’s gone for good.

Previous
Previous

The Search for Truth

Next
Next

Macroinvertebrate Studies Update