850,000 Klamath River Salmon Died From Gas Bubble Disease? Maybe

The ‘River of Death’ continues to earn its title…

The California Department of Fish and Wildlife’s (CDFW) use of the explanation of ‘gas bubble disease’ to cover the death of the 850,000 fall-run Chinook salmon fry seems questionable in the face the known conditions at Iron Gate Dam (days during & following release from Fall Creek) and the published science, which in summary suggests:

1. A pressure gradient is required; means the water behind the dam and the tunnel at Iron Gate Dam would need to be deep, say 60 to 100 feet of head water depth behind the dam (2 or 3 atmospheres pressure), assuming the subject fish are at depth, and remain at that depth for a time sufficient to allow gases to be saturated into blood and tissues. These conditions did not exist at Iron Gate Dam between February 26 and March 1st (period salmon passed through the tunnel). During that period, the water behind Iron Gate Dam was about 20-30-feet deep, equaling a maximum of 1-atmosphere of pressure.

2. The water would need to be supersaturated with dissolved air (oxygen) to allow absorption into the blood and tissues under increased water pressure over time. The water coming down the Klamath River through the Copco lake bed sediments and through Iron Gate lake bed sediments is laden with clay-particulates, dissolved nitrogen and phosphates, decomposing organic materials and other toxins, which minimize the water’s capacity to hold dissolved oxygen.

3. Finally, a sudden rapid reduction of pressure (decompression) around the fish would have to occur, causing gases in the tissues and blood to suddenly come out of solution, forming expanding gas bubbles. 

For A More Complete Understanding Watch: Boyle’s Law & Henry’s Law

Boyle’s Law 

Henry’s Law

Fish passing through a river tunnel under the dam, essentially at river-level on both the upstream and downstream sides of the dam (little/no pressure gradient = no decompression), does not provide the parameters normally associated to cause gas bubble disease.  


The narrative by CDFW suggesting that 850,000 taxpayer-funded fall-run Chinook salmon fry perished due to ‘gas bubble disease’ is certainly plausible, but questionable. 

Arguably, there powerful financial motives to deny the deadly impacts of sedimentation-turbidity (toxic clay-mud) on the salmon fry, especially because there are ten of millions of metric yards of the stuff still sitting on the lake bottoms of Iron Gate and Copco Lakes! 

And those tens of millions of metric yards of polluted clay-mud sediment will continue to erode and leach toxins into the Klamath River, even if planted seeds produce a little ground cover. 

The gas bubble tale seems to also work as a cover story in the event there was incompetence in the release of costly salmon fry into a polluted Klamath River.

Establishment of a fish model to study gas-bubble lesions


  1. Eric Wunsch

    The DFW says they tested for O2 and turbidity. How about heavy metals. Here is a paper on the effect of chromium on freshwater fish.

    • Avatar photo Jay A. Martin

      thanks for the link: another rabbit hole of study.. I found this interesting “After 96 h of exposure, fingerlings have been found to face the problem of imbalance in all the test concentrations. Mucus secretion rate has been found to increase in all concentrations after 96 h of exposure [14].

      then in the table 1: fry was 7.6 mg/l which is much higher than the river is showing but lower doses longer periods of time could equate?

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