Your comment on habitat is simply wrong. That being said while ocean survival is currently poor that is largely out of our control. What we can do is protect the fish once they reach our own waters and preserve existing habitat and restore the rest. I don't know a stream on Vancouver Island that hasn't been ravaged by logging including the Gold so to say the habitat is just fine is off the mark.
What Dave said was actually spot on. During the 80s, the Gold had one of the most spectacular steelhead runs for winter fish anywhere on the planet. While it has certainly been ravaged by logging, its in river habitat hasn't changed much since there. What has changed, are the ocean conditions up and down the coast. If you look at a river like the Megin, completely contained within Strathcona, never been logged in its existence, with huge stands of old growth cedars everywhere, you'll still see that its steelhead populations have tanked to almost non-existent numbers. I'm down in WA and our numbers have similarly dropped. It's the ocean. And that's why hatcheries wont work either. We can put as many fish as we want out to sea, but we are essentially putting cows out to an empty pasture. They wont survive. The hatcheries here in the states that have been successful have been planting SO many fish that just by a numbers game they eventually get a few back, but their return on investment (meaning how many steelhead they get back vs how many they plant) is the lowest it's ever been. In Puget Sound, in particular, the Tulalip tribe calculated that they were spending as much as 1000 USD in hatchery expenses PER FISH. Since it's federal money and the tribes are able to spend it however they want, they are continuing to finance the programs, but their yield is almost zero. When the ocean conditions were better, in the 80s, not only did we have improved sizes of wild runs of steelhead, they even had better hatchery rates of return, simply because the ocean was so much healthier.
I definitely feel you, that we should try to improve as best we can, what we can, which means improving freshwater habitat. But honestly, if they have the perfect gravel beds and the perfect stream flows, only to go to an ocean that is truly sick, we can't expect to see much benefit in terms of returns. Sadly, the science supports this. I know its not what any of us want to hear, but its the reality.
I love the Gold River. I hooked some of my first steelhead there, and to hear the old timers tell stories of 30 fish days on the fly during the winter not only blows my mind, but breaks my heart, to know that I never, nor will I likely ever, see days like those guys did back in the 80s, let alone when they first cut the roads into the area back in the 60s. I would have killed to fish the Heber during Haig- Brown's era. But no amount of funds will ressurrect that stream. Hopefully improved ocean conditions will improve fishing.
I suspect that overharvest of things like sandlance and herring have hurt our steelhead. Commercial by catch (much of it illegal from asia) has taken it's toll. Decadal oscillation giving us warmer ocean temperatures, "the blob", and acidification of the ocean from fossil fuel consumption are probably all contributing. And as long as China is in charge of most of that, we have little power over improving our situation.