The single most important thing that needs to be done in order to ensure that the orca families of J, K, and L pods continue to thrive in our inland waterways is to provide them with adequate food. And for these whales, that means salmon, and lots of it. Whale biologists have been sounding this alarm for years:
Linking killer whale survival and prey abundance: food limitation in the oceans' apex predator?
John K. B. Ford, Graeme M. Ellis, Peter F. Olesiuk, and Kenneth C. Balcomb
"Here we show, using 25 years of demographic data from two populations of fish-eating killer whales in the northeastern Pacific Ocean, that population trends are driven largely by changes in survival, and that survival rates are strongly correlated with the availability of their principal prey species, Chinook salmon (Oncorhynchus tshawytscha). Our results suggest that, although these killer whales may consume a variety of fish species, they are highly specialized and dependent on this single salmonid species to an extent that it is a limiting factor in their population dynamics. "