While Chinook may be preferred by SRKWs they certainly eat the other species when Chinook aren't around. Back about 20-25 years ago they cleaned out the Dyes Inlet runs of chum in December. To claim Chinook are their only food is a ploy to get Chinook specific actions taken like removal of the Snake River dams.

The fisheries that need essentially closure until definite recovery occurs are the marine mixed stock fisheries, including those that take the salmon's food resources and have salmon as (wasted) bycatch. Once the salmon have passed the whales, protection is not needed. That means that in-river fisheries, constrained by escarpment goals, can proceed. If the whales start moving upriver to eat, this may need reconsideration.