While this thread may be gargantuan, what is being discussed has been a topic of discussion amongst salmon harvesters for the past 5000 years. The present discussion has the possibility of drawing on information gathered by people whose interest is not always harvest, it's called science and in many cases it may be the same as traditional knowledge. It can be misleading though to quote second hand sources for science, the original work should be read.

We do know a great deal about what is going on in the ocean and salmon. It doesn't receive much attention from USA managers though because they are keyed to freshwater. Japan and Russia used to monitor high seas salmon conditions but recently have stopped. For NOAA the ocean ends 200 mile off our shores, they do not do salmon research in international waters. Presently there is no monitoring of salmon in international waters. There has been in the past, for over 50 years UW participated in some level of "High Seas" salmon research. If you are interested in ocean salmon science visit the following UW libraries web site and search the collection for High Seas Salmon. I think you will find about 500 down loadable publications. The top publication under recent submissions addresses many of the comments in this thread, you can read it before it is news.

High Seas Salmon

Many of the questions about steelhead and the "High Seas" were discussed in a recent UW SAFS masters thesis. It can be downloaded from the following site. It is 107 pages, much of the discussion of statistics and methods might not be of interest but it does address many of the questions in the last part of this thread. Megan Atcheson, the student who wrote the thesis received some support from WSC.

Interannual Variation in ...systems