This is objectively false. Salmon populations are more often than not considered in decline. The fish haven't "figured it out". They marginally persist solely due to intensive management that plainly consists of atrocities for species less popular in the media [0][1], millions spent on fish ladder theatre, and hatcheries.
The dominant mechanism in support of the fisheries being hatcheries that are basically a strangely laundered welfare program for indigenous, sport and professional fishermen each to their licensed proportion.
If you live in the Dalles, and you don't know the Columbia basin damns are an ecological nightmare.. it's unconscionable.
Not to mention the displacement of indigenous peoples from important traditional regions, the complete loss of stochastic annual flows feeding nutrient cycles in the river... etc etc.
Im no eco-activist. I don't necessarily think removing the dams would improve anything for anyone at this point, but if we're going to advocate for doing things a better way in the future - let's be honest: dams are horrible. The dams on the Columbia will eventually result in no salmon, no matter how hard we try. It's inhospitable. They used to run all the way up the snake into Idaho. Into IDAHO. Never again.
It's ok to advocate for energy, and the things you believe in, but let's not be belligerent about it - be honest.
In the Astoria maritime museum (several years ago now) I remember reading a passage that was proud of "..taming the wild Columbia, and turning it into a beautiful series of lakes and streams to wonderfully facilitate shipping and recreation.."
Some hutzpah, to think we know what we're doing.
[0] https://www.audubon.org/news/the-corps-cormorants-and-cull [1] https://www.marinemammalcenter.org/news/response-to-columbia...