million salmon would return every year, the greatest salmon fishery in the world. and now it is about a million. >> reporter: and most of those are hatchery fish. with weaker genes and less fat than the wild cousins. so the southern resident killer whales that live on chinook are starving. there are only 73 of this kind of orca left on the planet. and after a grieving mom pushed her dead calf around puget sound for weeks it rekindled a decade's old debate, salmon versus dams. >> what would you say to folks that would say the best thing that could happen for these animals is to take the dams down? >> i would say for the army corp of engineers, we're looking to do the right thing. we're looking to operate the dams that are here while taking a close look at what the future of these dams are in the region. >> reporter: to find the birth stream, many chinook out of the