Coho struggles

Cheesehead

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I've been following salmon restoration for many many years. Coho dying after rain events have been documented for decades. Even 5 or so years ago scientists had identified street run off as the cause, but still hadn't identified what specifically was causing the morality.

This is absolutely a major breakthrough. As this is something relatively easy to fix, not something so vague as "ocean conditions."

I've been sounding the alarm that our current state of salmon has more to do with micro contamination than it does habitat lots for years.

I'll go out on a limb and say we will find similar results in smolts exposed to fire fighting and wood preservative chemicals. That's where a lot of the leading research is occurring.
 
That is interesting. I have a hard time believing it's the main issue here in CA. Dams and major water exports to the Southern end of the state are likely much more significant. As neffa3 mentions above it's great that this is something easily fixed.
 
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That is interesting. I have a hard time believing it's the main issue here in CA. Dams and major water exports to the Southern end of the state are likely much more significant but it's still Salmon seem to have everything stacked against them.
It's not the only issue. And this particular issue is mainly just on Coho (it actually doesn't affect chum at all) but the idea of toxic chemicals in small doses causing population level declines is real.
 
I'll go out on a limb and say we will find similar results in smolts exposed to fire fighting and wood preservative chemicals. That's where a lot of the leading research is occurring.
I think you’re right on the money.
 
There was an interesting study done in UT regarding an increase in sterile male trout. They determined the cause was likely birth control pills. Apparently the dosages, to be sure they work, are higher than what the female human body can process. So the non processed estrogen ends up flushing out of the body, down the toilet and eventually into the rivers. The increased estrogen in the water then causes the male fish to become sterile. Sorta makes sense, but who’d have thought. Anyway, not trying to make any political statements. Just thought it was interesting.
 
There was an interesting study done in UT regarding an increase in sterile male trout. They determined the cause was likely birth control pills. Apparently the dosages, to be sure they work, are higher than what the female human body can process. So the non processed estrogen ends up flushing out of the body, down the toilet and eventually into the rivers. The increased estrogen in the water then causes the male fish to become sterile. Sorta makes sense, but who’d have thought. Anyway, not trying to make any political statements. Just thought it was interesting.
I've heard that idea floated but never read any research on it.
 
I've heard that idea floated but never read any research on it.
I've seen research on this affecting amphibian mating, it's a pretty logical step to assume there's effects to other species groups as well. It's just too bad we're not better at fixing our problems once we know the cause.
 
I've seen research on this affecting amphibian mating, it's a pretty logical step to assume there's effects to other species groups as well. It's just too bad we're not better at fixing our problems once we know the cause.
That's what I love about this finding. It's not complex and should a quick and painless one to fix.

We have a pretty robust wastewater treatment group at my company. It's be disheartening to learn how difficult and costly it is to removed the few contaminants that we're currently working on (N, P, coliforms). To try and remove something like Caffeine or Prozac would take more money that one might think, plus in some cases the technology simply doesn't exist.
 
Coho are struggling up here pretty much area-wide. Runoff from roads/tires isn't happening in, I'd guess 99% the rivers that are impacted. There is something going on in the ocean, be it the 3-4x the natural population of pink and chum salmon getting dumped form hatcheries, over fishing of other species, impacts to food chain due to climate change or pollution, etc. I don't really think that runoff with tire chemicals in it is the main culprit/driver, but could certainly be having some impact in other places.

As Neffa pointed out, there is some really weird shit that gets dumped into the waters after "treatment." Mine drainage and water treatment is 100x easier to control minus a couple constituents. Not that its cheap, but you can get clean water pretty easy, compared to organic compounds.

The best/most efficient stormwater treatment systems remove 60-70% of constituents collected in the runoff. The crap that runs off of parking lots is scary. Its not only the stuff that drips from cars, but also all the pollution in the air/dust that ends up in the runoff. In forested/green areas, most gets trapped in the soils/plants. May sound bad, but if you consider prior to the CWA, there was little to no treatment done.
 
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