When that statement was first made, in the initial state/tribal plan, many bios commented rather forcefully on the draft. The authors found creative ways to ensure the comments were not made public or responded to.

You are correct that they took a short data base. That is a very good way to cover past sins. Not only in loss of age/size but loss of abundance. If you "forget"how big they were or how old they were then you never need to restore those. Shifting baselines.

All that said, other stuff is beginning to happen in the ocean that is shrining fish and it is not the fisheries that catch them. Food resources are vanishing. The super-abundant pinks, at least in relationship to the rest of the species, are out-competing them.

The most interesting, to me, is that the warmer water selects against/kills big salmon. Say that there is plenty to eat but a belly full nets you 1000 calories per day. At some point, basic metabolism (it goes up as temp goes up in cold-blooded animals) consumes more than that 1000. The result is that you eventually starve with a full belly.