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.
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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. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5977408/
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?