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Comment by ed25519FUUU | Hacker News Reader

> This dam, which was constructed without a fish ladder or bypass, cut off the paddlefish from their only spawning grounds upstream, which had only been discovered in the late 1970s.

How effective are fish ladders? If they’re effective, shouldn’t we focus on building a fish ladder on all existing dams?

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Fish ladders are minimally effective. They are typically installed to add a rubber stamp to dams and say "look, we tried! It's not our fault the ecosystem is getting destroyed". Same thing with fish breeding and release programs.

Citation?

https://e360.yale.edu/features/blocked_migration_fish_ladder...

Thank you. The article notes that other pressures such as overfishing also contribute to the decline of fish populations, and that fish ladders on the Columbia river are successful.

No doubt there are some ineffective fish ladders out there, and no doubt dams have a negative impact on fish populations. Could better designed fish ladders and compensation channels mitigate the effect of the dam? I think so.

Fish stocks across all species are collapsing due to overfishing.

Well these fish were very large. I cannot imagine what a fish ladder would look like. There is one for salmon where I live and it is not that big. They have been trying to bring salmon back for over 30 years. Not much luck so far.

Maybe more like a fish lock.

https://en.wikipedia.org/wiki/Lock_(water_navigation)

No jumping required

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