Reintroduction: Time for a Change in Strategy

After 10 years of effort it is clear that the current approach to reintroducing anadromous fish into the upper Deschutes Basin above the Pelton Round Butte project is not producing acceptable results.  Fisheries managers acknowledge this but often state that it will take more time.  They reply that it has been over 50 years since these fish were cut off from their traditional spawning grounds and reintroduction is a complex problem.  This is true, but I believe the current dire state of steelhead returns to the Deschutes River should provide impetus to take bolder action.  This is a long post, but worth reading if you care about the future of steelhead in the Deschutes River.

In 1964 Portland General Electric (PGE) completed the Pelton Round Butte (PRB) hydroelectric project near Culver.  PRB dammed the Deschutes River just below where it is joined by the Crooked and Metolius rivers to create Lake Billy Chinook (LBC), Lake Simtustus, and provide low cost, “green” electricity for PGE customers from Portland to Salem.  PRB also decimated salmon and steelhead populations in the Deschutes Basin.

Spring chinook salmon, sockeye, and summer steelhead were blocked from their primary spawning grounds in the upper Deschutes Basin.  Round Butte Hatchery (RBH) was installed in an attempt to mitigate the loss of critical habitat but anadromous fish populations have never recovered.

In June 2005 PGE and the Confederated Tribes of Warm Springs (CTWS) were granted a new 50-year license by the Federal Regulatory Energy Commission (FERC) to continue operations at PRB.  As part of that license PGE/CTWS were required to reintroduce naturally spawning, self-sustaining salmon and steelhead populations in the upper Deschutes Basin.

After study, it was determined that installing the Selective Water Withdrawal (SWW) tower and fish transfer facility in LBC would be the most viable approach to reintroduction.  In support of that effort, every year since 2008 the Oregon Department of Fish and Wildlife has planted over one million RBH-reared steelhead and chinook into the middle Deschutes, the Crooked, the Metolius, and their tributaries.

Well over $200M and countless hours of effort have been invested in this project but the results have been extremely disappointing.  Results are nowhere near what was expected when the reintroduction efforts were started.  With a few exceptions, trivially small numbers of adult fish have returned and at best there has been limited natural spawning.

There are numerous reasons for this, many of which are outside the control of PGE/CTWS.  Anadromous populations throughout the Columbia Basin are plummeting (the Deschutes is a tributary of the Columbia).  Global warming is heating the ocean and impacting the food web.  Dams on the Columbia reduce passage, eliminate spawning habitat, and warm the river to often lethal temperatures.  Irrigation withdrawals in the upper Deschutes Basin do the same.  Drought conditions during many of the past few years have also impacted spawning and rearing habitat.  Predation by birds and pinnipeds (seals and sea lions) on dwindling fish populations have had an increasingly significant impact.  Pollution from agricultural and urban runoff impacts juvenile fish and increases algae.   Commercial and tribal net fishing kills steelhead even when they are not the target species.  Even with best practices, sport fishing plays a role by  reducing the rate of spawning in released wild fish and killing some.

There are issues at PRB as well.  Surface flows to the SWW have not been strong enough to attract the desired numbers of smolts (1 year old fish ready to head to the ocean), although that has recently been helped with nighttime releases of water during outmigration periods.  Lack of volitional upstream fish passage at the Opal Springs Hydro facility at the mouth of the Crooked River just upstream from LBC has also been a significant issue.  (The Crooked River and its tributaries were historically the primary spawning grounds for Deschutes Basin steelhead.)  Returning fish are now trucked around the PRB complex and released into LBC only to be blocked by Opal Springs dam.  Most returning adults have unsuccessfully attempted to go up the Crooked and largely end up wandering around LBC until they perish.  This problem should soon be solved with the fish ladder now under construction at Opal Springs.

The current plan is to largely continue with the existing approach but modify hatchery and rearing practices.  For example, increasing the number of planted smolts over fry (a few weeks old).  The percentage of RBH-reared planted smolts that make it to the SWW is lower than desired but much higher than the percentage of fry who live in the river for a year before smolting.  Also, planted smolts start migrating out within days which reduces potential impact on resident wild, native fish like redband trout.

Planting smolts has not yielded improved adult returns but smolts have only been used for a couple of years.  Also, attempts are being made to improve smolt survival by placing them in acclimation pens in upper Basin rivers and tributaries before they are released.  This spring smolts placed temporarily in acclimation pens were captured at the SWW at a higher rate than those immediately released into rivers.

All these efforts should be beneficial but at this point it is believed by many fisheries biologists that dramatic improvement will not occur until the use of hatchery fish is curtailed.  Acclimation pens and nighttime water releases will help, but RBH fish have been segregated and inbred for approximately 50 years yielding highly domesticated fish.  These fish also introduce the possibility of degrading wild, native fish genetics if cross breeding between resident redband trout and hatchery steelhead occurs.  Consensus is growing that planting hatchery fry and smolts is not the path to wild, self-sustaining populations.

There is a vocal group who advocate for shutting down the operation of the SWW altogether.  They point to the lack of reintroduction success and claim the SWW is degrading the lower Deschutes.  I have reminded some leaders of this community that reintroduction is a requirement of PGE/CTWS’s FERC license and have asked for their alternate reintroduction plan.  Their response has been to release returning adults directly into upper Basin rivers and tributaries rather than into LBC.  This idea certainly has merit but does not address the primary issue of how to improve the capture outmigrating smolts.

Currently, outmigrating smolts are captured at the SWW.  If they are not captured there they will have to be captured before they enter LBC.  No one is in favor of building new dams where the middle Deschutes or Metolius meet LBC for smolt capturing.  Further, the use of weirs or screw traps on these rivers would be ineffective to capture viable numbers of smolts during high spring time flows when outmigration occurs.  This is why the SWW was selected as the preferred option.

During the relicensing period over a decade ago, many advocated for passing wild adults into LBC where they could then find the upper Deschutes Basin river or tributary to their liking.  It was thought that wild, native fish would provide the best chance for success.  This approach was not implemented over concerns about impacting the already threatened population of wild steelhead in the lower river.

Another concern was the potential to introduce new diseases into, or change disease prevalence in, the upper basin.  This concern is understandable but new diseases could be introduced into the lower river by stray fish at any time.  Further, the hope of some to eventually remove the dams would also introduce this risk.

At this point it seems evident that it is time to reexamine the current approach to reintroduction.  Fortunately, there is growing acknowledgement of this by biologists in the field.

One new approach could be to pass some returning hatchery-origin adults into LBC (fish that were raised in RBH and released directly into the lower Deschutes).  While these are genetically inferior to wild fish, returning RBH adults have at least shown the ability to survive outmigration, life in the ocean, and successfully return with very low stray rates.  They have the same genetic material as the hatchery fry and smolts currently being planted in upper Basin rivers but have self-selected for survival.  Passing large numbers of these fish into the upper Basin could provide a higher chance for spawning (although it has been 50 years since any of them did).  These fish would also avoid the potential issue of introducing non-Basin diseases carried by juvenile fish from other watersheds.

Of course, using low-quality hatchery fish to create a wild population is not the most desirable approach.  There are few examples of hatchery fish from long established broodstock successfully being used to establish wild populations.

Another idea would be to use a small number of wild fish as hatchery broodstock (wild females bred with wild males).  The resulting smolts would be planted in upper basin rivers.  It is well known that even these first generation hatchery fish are degraded when compared to wild fish but it is thought to be the best way to ensure that large numbers of close to wild smolts can be planted.  “Wild broodstock” have been successfully used in other Oregon rivers. No one seems to be advocating for releasing true wild adults in the upper basin to naturally spawn at this time.  There just are not enough of them to justify the mortality risk.

Over time all of the current RBH stock could be replaced with these first generation hatchery fish, including those released directly into the lower river.  In the best case scenario, wild returns would reach levels that would allow managers to discontinue planting of hatchery fish altogether.

There is growing consensus that major changes to the reintroduction program are needed if it is going to be successful.  I hope that they are tried soon.  Wild steelhead returns are plummeting.  Without major changes we may see the extinction of wild steelhead in the Deschutes in the not too distant future.