Guest Commentary

Editor's Note: This article is continued from the June 6, 2024 edition. Author Gerald Barron of Save Family Farming (savefamilyfarming.org) presents data that contends the condition of the chinook salmon fishery is impacted by numerous factors and that "habitat," such as the four Lower Snake River dams, is not doing the most harm.

By Gerald Barron

Save Family Farming

–Continued from June 6

The report quoted Katie Howard:

"She says between nutrient deficiencies, disease, and heat stress, it's hard for Chinook salmon to catch a break. 'It's both freshwater and marine issues acting on the adult spawners that may lead them to either not make it to the spawning ground, to make it and not spawn, or to leave eggs that don't really have the nutrients that they need to be successful and survive,' Howard said."

Ironically, the warmer ocean conditions may contribute to the abundance of sockeye salmon. Howard:

"The warming temperatures produce a lot of algae, and the algae helps feed the little critters that the [sockeye] smolt are feeding on. And so there seems to be some positive effect of these warming temperatures on sockeye because they live in this really unique habitat and they can take advantage of that."

BC science study shows rivers with dams and without dams both suffer from Chinook declines

In September 2020 fisheries scientists from Kintama Research Services in Nanaimo, BC published an article in Fish and Fisheries titled: "A synthesis of the coast-wide decline in survival of West Coast Chinook Salmon". In the course of a different study, they discovered "that Chinook survival in many rivers of the Strait of Georgia region had fallen to levels well below those reported for Snake River Chinook."

To make this clear: the Snake River, which is the focus of calls for dam removal, is actually faring better in Chinook recovery than many rivers without dams. This is significant because of widespread belief that the Snake River dams are harming Chinook. The four lower Snake River dams are presented as a primary cause of Chinook decline and the greatest obstacle to recovery. This study clearly demonstrated that is not the case. If the dams were the problem then other river systems would show much stronger returns. Smolt-to-adult (SARs) is the key measurement of run strength as it shows how many adult salmon return to their spawning areas compared to the number of smolts that left. The authors wrote:

"Within the Columbia River, the SARs of Snake River populations, often singled out as exemplars of poor survival, are unexceptional and in fact higher than estimates reported from many other regions of the west coast lacking dams. Given the seemingly congruent decline in SARs to similar levels, the notion that contemporary survival is driven primarily by broader oceanic factors rather than local factors should be considered."

The study area included the entire West Coast, and provided results consistent with the more recent Alaska report above as well as numerous other studies:

"We show that, overall, Chinook salmon survival (SAR) has decreased by roughly the same amount everywhere along the west coast of North America and has now reached similar or lower survival levels than Snake River stocks."

The authors repeatedly point out that the data do not support the conventional wisdom that the Snake River has unique problems with Chinook returns that are directly related to dams. The fact of general decline, including Asian Chinook, points to ocean conditions as the Alaska fisheries scientists showed. The Kintama report continues:

"The similar timing of the decline in the Salish Sea, west coast of Vancouver Island, and Columbia River Basin suggests the primary influence of a broad ocean driver (Beamish, 1993; Beamish & Bouillon, 1993; Mantua et al., 1997). The evidence for a roughly similar drop in Asian Chinook catches reviewed above also indicates that the geographic footprint of any ocean (or freshwater) driver must either be large or that many populations must migrate to common geographic regions where their survival can be similarly reduced."

The Snake River Chinook populations are actually doing better than river systems with no dams or other human infrastructure, which they refer to as "anthropogenic freshwater habitat impacts." This study makes very clear a central point of this paper on misdiagnosis: removing dams probably would not improve salmon returns despite the very high costs involved. The report concludes:

"The recent recognition of the decline in Chinook returns across essentially all of Alaska and the Canadian portion of the Yukon River, where anthropogenic freshwater habitat impacts are negligible, is another example of how simple explanations are potentially flawed. If survival across this vast swathe of relatively pristine territory is severe enough to seriously impact salmon productivity, then there is little hope that modifying freshwater habitat in more southern regions will support a newly productive environment for salmon."

Study shows impact of predation on Chinook and points to need for control

Both wild and hatchery production of Chinook have increased but without a corresponding increase in adult returns. Ocean warming is likely the primary cause of ocean mortality of Chinook, but there is little near term that can be done to mitigate this very serious problem. Another significant reason, the science studies show, is predation.

This problem is particularly acute in the Salish Sea where the consumption of smolts by harbor seals is concentrated. The study published in Nature led by NOAA scientist Brandon Chasco shows that harbor seals from Alaska to California consumed 27 million Chinook in 2015. But in just one small region –– the Salish Sea –– 86.4% of those Chinook were consumed by harbor seals. The numbers of predators in this small area have grown from 8600 in 1975 to 77,800 in 2015. Numbers increased in this region much more than in other areas in part because the local pod of killer whales, unlike their cousins, do not target harbor seals as a food source. Consequently, they are being out competed for their primary food: Chinook. What makes this difficult is that while both hatchery and wild production of Chinook has greatly increased to 400 million in 2015, the ocean losses due to warming and predation appear to negate this gain.

Predator control is therefore the most important and viable solution to improving Chinook returns. Tribal leaders have been calling attention to this for years. The leading science group in Washington State recently communicated that Chinook recovery depends on control of pinniped predators.

Public attention is crucial for necessary action to be taken. Predation by sea lions in the Columbia river received far more public and media attention than harbor seal predation in the Salish Sea, despite the fact that the impact on Chinook is many times greater. Congress acted to allow limited removal of the voracious predators. Similar attention to the predation in the Salish Sea will be necessary for lawmakers to take what can be a controversial solution.

Summary

The purpose here is to raise an important question. Media reports generally focus on the position of advocates who claim that Chinook recovery is first and foremost a habitat issue. The studies highlighted here and detailed in the Appendix suggest this may be a great misdiagnosis.

It would be tragic if billions were spent, family farming in the state and region permanently harmed or even lost, and the iconic Chinook remained elusive. The fact that relatively simple and less costly solutions that would prove far more effective are available would make the tragedy that much greater. Certainly, the importance of the issue requires a closer look.

-Barron is Research Director with Save Family Farming. Email: [email protected].