4Salt,

I’d venture that capacity is significantly reduced from a benchmark time of, say, 1850. There remains a lot of capacity, reduced by the reduction of oxbows, side channels, backwater channels, sloughs, estuary, and lower summer flows due to land use changes. Next, I’d venture that productivity is far more significantly reduced than capacity. Productivity reductions come in the form of siltation that reduces egg to fry survival, reduced population of some of the benthic macro-invertebrates that fish forage on, and probably the smaller amount of marine derived nutrients in the form of fish carcasses. Productivity is further reduced by stream channel simplification - straightening, lack of LWD, etc.

That 4 of the 5 largest coho escapements of the past 40 years have occurred in the last 5 says that both productivity and capacity are large and have been underutilized for the last 4 decades.

I don’t think there’s much relation between large coho runs and smaller steelhead runs. As juveniles, the species partition rearing habitat pretty effectively, and it’s quite common for good coho rivers to also be good steelhead rivers. Remember, it’s not just the Sky. Every Puget Sound river basin is getting poor steelhead returns compared to the 80s. The puzzle we can’t figure out is why coastal steelhead have recovered from the downturn of the 90s, but the Puget Sound streams have not.

Sincerely,

Salmo g.