Rivrguy,

Habitat limits fish populations, now and in 1850. The difference is that it was the pristine condition of habitat that was limiting populations in 1850, but limiting them to a much higher level, estimated at 10 to 20 times larger than today's populations sizes.

Carcassman,

I think food, along with space, are generally considered to be key parameters of fish habitat. Each of those is then sub-divided into their many elements (space: pool, glide, riffle, over-head cover, substrate, channel complexity, etc., etc.; food: aquatic insects, terrestrial insects, species, fish, fish products, etc.)

OncyT,

It's my understanding that the wild PS chinook being harvested at higher than MSY aren't being harvested at that rate for the reason of MSY, but rather to exact reasonable harvest rates on co-mingled hatchery chinook. IMO it's ludicrous to believe that it's feasible to harvest hatchery chinook from the Green, Puyallup, and Skokomish Rivers via gillnet fisheries and attain desired exploitation rates (very low) and escapement levels of the co-mingled wild chinook. And that's without going into the subject that the co-mingled wild chinook are essentially hatchery origin NORs, but that can be for another day.

I think the same thing applies to several of the LCR tributary hatchery chinook populations, excepting the Lewis. The tributary habitat is trashed, endemic wild chinook populations are far more likely than not extirpated, and the NORs that exist are predominately, if not entirely, of hatchery origin. I suspect that any exploitation rate above "slight" will exceed the MSY rate of those populations, particularly if they are sustained only due to the presence of hatchery strays. It's going to be a PITA to prove it, but perhaps the Grays River weir will demonstrate just how poor natural reproduction of fall chinook, unaided by hatchery strays, is in small tributaries that are environmentally trashed.

I agree in regards to the PS steelhead populations. When R:S < 1.0, almost any fishing mortality at all exceeds MSY. Again, that doesn't make over-fishing the limiting factor, just a contributing one when either fresh and or marine habitat is the proximate limiting factor.

Aunty,

Unfortunately, the MDN of hatchery fish seldom ends up where it has the potential to contribute to productivity of natural fish populations. All the tossing of hatchery carcasses that goes on is analogous to applying a bandaid to a sliced carotid artery; not much help.

Milt,

I don't think food is so much over-looked as it's just not specified, just as we don't specify the many aspects of space as it pertains to habitat. We can generally talk about habitat limiting productivity without every time adding the details of channel complexity that creates more individual fish territories per unit area, and we can say that habitat is limiting without every time mentioning that it ain't really habitat if there is no food, or that it's poor habitat if there's very little food. Imagine Costco, only empty save for a single jar of peanuts; everyone understands that there is a lot of space, but it isn't very good habitat under those circumstances.

Sg