OK one more interesting excerpt from that "exhaustive" search...

Fat levels within individual species may vary dramatically depending upon the specific characteristics of their home river.

For example, the Copper River is a relatively “steep” swiftly flowing river, so Sockeye and King salmon swimming against this current must have greater energy (fat) reserves than those returning to other rivers.

In contrast, Bristol Bay Sockeye and King salmon, which have a relatively easy migratory journey, may have half as much fat as their Copper River counterparts

By far the fattiest, richest King salmon of all come from the Yukon River, which is both the coldest and largest of Alaska’s salmon spawning rivers.

http://vitalchoice.com/shop/pc/articlesView.asp?id=972


They didn't mention the Columbia. And upriver CR spring chinook do not show up in any of the established troll fisheries, so the comparative lipid content study excludes them. I still maintain that out of all the chinook strains I have had the chance to partake, CR spring chinook are probably the finest-eating salmon to cross my palate.