I will touch Chinook only as several others here will do others more justice. When you MSY fish you are in reality flat lining a run or species. In nature you can have floods, low flows, all which limit and impact runs but with time a year with good river and ocean will come around on the low side and nature brings it back up to the naturally sustaining level of the others.

Second in the case of ocean fisheries they are the primary cause as of the loss off 5 & 6 age groups which are the big guys in the pictures. Longer in the ocean, a smaller % of the run, most extreme harvest pressure and few remain in WA. Take the Elwha, when the dams are gone most stocks should recover at a reasonable rate but not Chinook. The Alaska & BC ( and tribal & US sport ) will continue to maintain the pressure that reduced Chinook in the state to 3 & 4 yr age groups and the genetic loss will not be reversed.

Over harvest and just as importantly how & where it takes place has a dramatic impact on Chinook. It differs say from the Columbia to PS but it is always present and the effects are as long tern genetically as hatchery practices and habitat loss. It is a invisible process of genetic attrition that one sees only through the eyes of history. My father caught 40, 50 & 60 lb Chinook on the Satsop when I was 6 yrs old ( yes AM that is 56 yrs ago ) now the population is 3 & 4 yr classes and few get above 30. We like to scream dirty tribes & gillnetters, truth is the real driver was and is the ocean commercial and sport. Chinook never could, nor will be able to genetically sustain the level of ocean intercept fisheries applied to them.