There's a very important nuance to keep in mind. As you mentioned, there may be a host of factors, but what we experienced with the return of smolts—the young salmon—in 2023 and 2024 was a sudden and abrupt decline. Since then, we've certainly come to believe that there is a primary cause. Everyone agrees that it's probably related to climate change. That said, that's the indirect cause.
What's the direct cause? Is it a lack of food? Is it early migration due to water temperatures? There's a lot of information to consider.
One thing is certain: We have extremely productive rivers that have seen excellent smolt runs. The problem is that they don't return the following year.