Somebody has mentioned, too, that in S Sound there are now more anchovies (I believe); they would appear to have replaced, numerically, the herring.

But, if they are not available to salmon, are the wrng size at the wrong time, etc. then they are of no help to the predators. Tug's right that the ecosystem has radically changed. Since nature abhores a vacuum (except when it is seen in leadership positions) it may be that what is in S Sound now is not working for the salmon.