C'man,

Yes, those rivers are more productive. The pH is greater than 7, tending toward alkaline, with more calcium carbonates. This results in a denser biomass of aquatic invertebrates and fish food. An acre of river there grows a lot more pounds of fish per year than our coastal rivers. Our rivers have a pH of 6.5 to 7, almost never greater than 7. So the water tends toward acidic and produces a far lower abundance of aquatic invertebrates and fewer and smaller trout.

This is why high salmon escapements make such a difference. While western WA rivers produce few and small trout, coastal AK rivers, where sockeye salmon escapements remain generous, there are large populations of trout that attain larger size. Sockeye eggs and carcasses drive those aquatic ecosystems.

But I digress. WDFW hands NT recreational fishing management off to the treaty tribes, throwing many recreational fisheries that have extremely low salmon impacts, under the bus. Thus there is a decreasing incentive to fund anadromous fish management at WDFW.