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Vital Connection: Orcas, Salmon & the Snake River Dams

By Sharon Grace

Southern Resident Orcas Are Critically Endangered

  • NOAA listed the Southern Residents as endangered in 2005 when there were 88 orcas. A decade later, there were 81.  In 2019 there are 75.

  • The SRKW historical population was approximately 140 whales (Species in the Spotlight Report, p. 30.)

  • Per the NOAA 2008 recovery plan, the SRKW population must increase by an average 2.3 percent per year for 28 years to be removed from the Endangered Species list. NMFS (2008) Recovery Plan for Southern Resident Killer Whales (Orcinus orca), p. v.

  • The Southern Resident community of orcas is among the eight most endangered species protected by NOAA, per NOAA’s Species in the Spotlight Report, May 2015.

  • The Southern Residents live or die based on Chinook salmon abundance.

  • Approximately 80% of their diet is Chinook salmon.

  • Within the United States, the Columbia/Snake River watershed is the most important source of salmon for Southern Resident orcas

  • Over the winter months spring/summer Chinook, due to their high fat content and high nutritional value, are crucially important to Southern Resident orcas.

1.  NOAA's satellite tag research and acoustic recorders deployed on the coast show Southern Residents’ presence, centered on the mouth of the Columbia River frequently during the winter and spring months, through April when the Snake River adult spring/summer Chinook are entering the Columbia River. ​

2.  Prey samples collected by NOAA show Southern Residents eat Columbia and Snake River Chinook.


Important.  Toxics remain sequestered in SRKW’s blubber if they have sufficient prey.

Snake River Salmon Are Threatened or Endangered

  • All four Snake River salmon and steelhead runs are listed as endangered or threatened under the Endangered Species Act.


  • Salmon are not recovering despite nearly 25 years of litigation and more than $700 million total spent on Snake River fish passage improvement structures. These improvements were expected to lead to Snake River salmon recovery. They haven’t.


While fall Chinook have returned in large numbers, 80% of spawners are hatchery derived fish. Breaching will recover wild stock because it will expand spawning habitat and will reduce the density dependence that is limiting recovery potential.

  • The cost now on a structural improvement is roughly five times more than estimated in the Army Corps of Engineers’ 2002 LSR Feasibility Study. These costs would be eliminated with dam breaching.


  • In 2018 the Columbia Fish Mitigation Program sunsets. (This is what pays for the improvements.) Then any fish passage improvements come out of the Corps’ operations and maintenance budget.


  • Survival of wild salmon and steelhead runs requires a minimum 2% smolt-to-adult survival rate (SAR). Recovery of Snake River salmon and steelhead requires a 4%-6% SAR. The overall SARs for Snake River populations of salmon and steelhead are not meeting this goal(1).  The SAR for wild Chinook salmon over the past 18 years has averaged .59%. This is not recovery.


  • In 2013 NOAA Fisheries acknowledged that Snake River spring/summer Chinook and steelhead runs are not increasing, but instead have been “relatively stable since 1999 with the exception of lower estimates in 2001 and 2004.” In addition, the runs were lower in 2013, 2014, and 2015 due to hotter water and lower flow.  The runs have continued to decline.


  • In 2015 the Snake River became a killing field for the larger than average salmon runs that were returning to spawn. Due to drought, climate change and the four dams, superheated water temperatures killed 80% of the returning Sockeye salmon and were often lethal to the fall Chinook.


The Four Lower Snake River Dams Are the Problem


  • The dams have been killing upwards of a million salmon and steelhead annually for more than 40 years.


  • The dams impede passage of salmon and steelhead between their spawning and rearing habitat and the Pacific Ocean.


  • The dams have inundated Snake River fall Chinook salmon spawning habitat.


  • The dams have disrupted the free flowing Snake River and turned it into a series of slack water reservoirs.

  • Snake River slack water reservoirs are deadly to salmon and steelhead.

1. Slack water reservoirs slow smolt migration to the ocean.

2.  Slack water reservoirs cause water temperatures to rise to lethal levels for salmon and steelhead. The four Snake River dams can add 6 to 12 degrees Fahrenheit to water temperatures. The high water temperatures caused by drought, climate change and dams were catastrophic to migrating fish in 2015.

3.  Since the reservoirs are ideal for salmon predators, they allow increased predation on salmon and steelhead by both native and non-native predators.

4. The reservoirs increase disease both by degrading the water quality and increasing its temperature.

5. Slack water reservoirs interfere with smolt navigation and physical development.

Steelhead, and Sockeye, 2014 Annual Report, BPA Contract #19960200, November 2014, p. xxv & Chapter 4; 2014 FCRPS Biological Opinion.


The Snake River Fish Mitigation Measures Do Not Work

  • Hatcheries are not able to compensate for dam impacts to wild salmon. Instead, hatchery fish compete with wild salmon and impair genetic diversity in both wild and hatchery fish.

  • Barging and trucking salmon around the dams have not restored salmon and steelhead runs. This unnatural transporting interferes with smoltification, and with navigation by adults returning to spawn. Smoltification is the complex transformation that involves physiological, biochemical, morphological, and behavioral changes, that juvenile salmon undergo to transition from living in freshwater to living in saltwater.

  • The design of the dams causes hydraulic action that creates eddies strong enough to trap smolts migrating down river. This makes them easy prey for predators. Bounties are now paid of $5 to $8 per pike minnow in an attempt to diminish this natural predator that thrives in the slow moving water created by the dams. In 2010 one angler made $81,000 in bounties from fishing out pike minnows in the reservoirs. The bounty earned by the top angler over the last several years averages $70,000.

  • Severe reductions in commercial and sport fishing have not stopped the salmon and steelhead decline.

  • The federal agencies have spent hundreds of millions of taxpayer dollars to improve fish passage through, over and around the dams. None of this has worked to recover salmon and steelhead runs on the Snake River. Spending hundreds of millions of dollars more to mitigate the dams’ impact on salmon is a waste of taxpayer dollars.


The Snake River Dams Contribute to Climate Change

  • “Until recently, it was believed that about 20 percent of all man-made methane emissions come from the surface of reservoirs. New research suggests that figure may be much higher than 20 percent, but it’s unclear how much higher because too little data is available to estimate. Methane is about 35 times as potent a greenhouse gas as carbon dioxide over the span of a century.” 


The Snake River Dams No Longer Meet their Congressionally Authorized Intent, If the Costs Exceed the Benefits

Hydropower Generated by the Dams is Not Needed

  • The Snake River dam hydropower is surplus. If the dams are removed, the energy produced by the dams does not need to be replaced.

  • Even if hydropower from the Snake River dams did need to be replaced, it has been replaced more than four times over by wind and solar energy. This energy is greener than hydropower, since it does not destroy entire watersheds.

  • Energy oversupply is a costly problem.  BPA sells half of its power for bargain basement spot market prices that are often far lower than BPA’s cost to produce energy.  This is driving BPA into dire financial straits.


The Navigation Benefit is Negligible

  • The Snake River is a “river of low use” pursuant to the Army Corps of Engineers’ definition.

  • Since April 8, 2015 all container shipping on the Snake ceased when the last two container shipping lines, Hanjin and Hapag-Lloyd pulled out of the Port of Portland.

  • Bulk shipping has been declining for 20 years and is being replaced by rail.


The Dams were Not Constructed for Flood Control

  • Congress did not authorize flood control as a permitted use of the dams.

  • The dams are “run of the river” dams, meaning they were not built to store water.

  • Due to sediment build up, Lower Granite Dam actually creates a flood risk to Lewiston, Idaho.


Irrigation Issues Can Be Mitigated

  • Ice Harbor Dam is the only one of the four dams that provides irrigation for farms. If the dams were breached, irrigation intake pipes could be extended to the river.


Other Points


In a Biological Opinion, NOAA could tell the Army Corps and other involved federal agencies that breaching is a Reasonable and Prudent Alternative to avoid jeopardy to endangered and threatened species listed under the Endangered Species Act.


Presidential Executive Action is Legal, Feasible and Practical

  • The dams are harmful and costly. They do not “pencil out” because the costs exceed the benefits. The Principles and Guidelines for Water Resource Agencies require the benefits to exceed the costs.

  • Congressional authorization is not needed to breach the dams, since their economic benefit does not pencil out.

Breaching is Not Complicated

  • Breaching can be done through channel bypass by removing part of the earthen berms adjacent to the concrete structures. Structures can remain in place.


Congressional Appropriation to Breach the Dams is Not Needed

  • Dam breaching can be paid for through fish mitigation credits.

1.  Comparative Survival Study of PIT-tagged Spring/Summer/Fall Chinook, Summer Steelhead, and Sockeye, 2014 Annual Report, BPA Contract #19960200, November 2014, p. xxv & Chapter 4; 2014 FCRPS Biological Opinion.

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