Bob I'm pretty sure I read that book back when it came out, sounds familiar anyway. Once again one of the problems on the Skeena as with the Dean was the establishment of spawning channels. In the case of the Skeena it was Sockeye enhancement on the Babine and the most affected stocks were the early returning Upper Morrice Steelheads and the early run Cohos that you mentioned in your post.
Less I forget the full scale destruction of Gosnell Creek by clearcut logging on a "Grand Scale" just about wiped out that bountiful run of small race steelheads or certainle added to there decline through lost habitat and increased siltation not only in Gosnell Creek but downstream in the main Morrice right on down into the Bulkley.
The problem with these enhancement projects regadless if they are hatcherys or spawning channels is they put a pulse of surplus fish in a system that get harvested and this usually menas more time for fishing which puts a strain on the smaller less abundant indeginous populations not only of Steelheads and Cohos but too the very Sockeyes that are being enhanced!
The sucess of these Spawning Channels has been detrimental to many discreet stocks but they have created a lot of income for the various individuals that are engaged in the extraction of these resources.