Decades of Effort Restore Steelhead and Salmon Passage on Alameda Creek

chihuahua 3 hours ago | parent | next [-]

There is similar work going on to restore fish passage underneath I-90 near Issaquah, Washington. Although in that case, the part of the streams that's currently inaccessible is less than a mile for most of them, and 2 miles for one of them. It's a major undertaking to restore a stream bed or channel underneath the interstate.

This will benefit Kokanee Salmon, a kind of salmon that spends all its life in fresh water and does not migrate to salt water like most salmon.

In Lewis Creek, they currently have access to only 1/2 mile of the creek, but in 2021 there were about 1000 of them returning (from Lake Sammamish) to spawn.

	▲	anitil 2 hours ago \| parent [-]
		That's really surprising that they could survive with such a small range! How are they counted during their migration?

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burner420042 31 minutes ago | parent | prev | next [-]

> PG&E, Oliver de Silva, and a Bay Area foundation provided the rest of the funding to complete the project.

Why was a 'Bay Area foundation' referenced yet left nameless? I never understand the logic behind this convention..

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Dansvidania an hour ago | parent | prev | next [-]

Silly question but if I remember correctly salmon go back to reproduce where they spawned. This suggests that once access is cut up a river, that location loses its salmon (can’t get there, so they don’t reproduce?)

Do they artificially reintroduce the salmon once access is restored or does that “neighbourhood” of salmon somehow survives and keeps trying every year ?

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burner420042 an hour ago | parent [-]

IANAS but my understanding is they keep going upstream - while there's current to push against them - as an instinctual response. I believe water temperature also plays a role.

Salmon hatcheries also artificially boost the quantity of salmon in the stream.

If a salmon hatchery released salmon at the base of a dam, when the fish return and the dam was now gone, they'd just keep going.

However, there's more to it than this, because dammed rivers lacking salmon hatcheries have seen salmon runs start once the dams are removed.

I don't think the old adage that salmon will only return to their original spawning grounds is the whole story.

	▲	wahern 28 minutes ago \| parent [-]
		> I don't think the old adage that salmon will only return to their original spawning grounds is the whole story. Some percentage will just enter a different stream. Straying could be a genetic strategy, imperfect behavior, accidental, or some mix. And they're not all necessarily distinct; e.g. the genetic strategy might simply work by reducing accuracy in locating the original spawning ground. Consider that even before humans streams and rivers would naturally be dammed, diverted, or otherwise change in a way that made it more difficult or impossible to reach the original spawning ground. What would be interesting is if the ratio of various phenotypes, like those that effect straying, has changed in response to the ecological upset caused by humans.

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kiernanmcgowan 5 hours ago | parent | prev | next [-]

Such good news - for those looking for a relaxing hobby fly fishing is an excellent sport to get into. You spend all day standing in a river trying to out smart some fish and trout are exceptionally beautiful creatures up close.

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RajT88 4 hours ago | parent | next [-]

Agree. I think most fish are beautiful in a way, even the "ugly ones".

What I really love about the fish under discussion here is, for a long time they had no clue why some rainbow trout became steelhead, and some didn't. (They still don't know 100%) Such an interesting story, and a regular rainbow and a steelhead just seem almost like another species - different size, behavior and even taste when you eat them.

	▲	bonzini 4 minutes ago \| parent \| next [-]
		People for a long time didn't know what the reproductive cycle of eels is like, because they travel all the way from the Atlantic ocean and back while maturing, so nobody had ever seen a juvenile. Too bad they're critically endangered.
	▲	a2tech 22 minutes ago \| parent \| prev [-]
		You want to have fun, get two fresh water fish biologists in a room and ask them if steelhead and rainbow trout are different species. Everyone has a different opinion they believe in passionately.

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boston_clone 2 hours ago | parent | prev [-]

Not quite as relaxing if you’re the fish!

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anenefan 2 days ago | parent | prev [-]

It's so refreshing to see a big company like PG&E reach out to help restore fish breeding ground even if at base level it was a win win situation.

	▲	culi 2 hours ago \| parent [-]
		Well... sure but they created the problem in the first place... I'd like to live in a world where a company picking up after itself isn't "refreshing"