Pretty easy to see what went wrong. Once the eggs were taken and the fish were reared in a hatchery, they ceased to be wild. All fish with "wild" characteristics, (shy, territorial, afraid of fish feeders, not tolerant of handling or disease, etc.) died in the hatchery environment, and all of the fish with domestic characteristics (tolerant of crowded conditions and disease, not afraid of handlers or feeders, etc.) survived. These survivors were not as fit as hatchery broodstock smolts, however, as they likely had some residual wild tendencies that caused them to be more susceptible to the diseases and stresses in the hatchery environment and caused them not to grow as fast or as large. All else being equal, small hatchery fish do not survive as well as large hatchery fish. Larger fish are faster, so they can get away from predators easier. Larger fish can also handle more starvation time until they figure out how to eat without being fed. Usually that means they have to wash out into the ocean during a year of high productivity, where feed can be had just by opening their mouths. That's really why we got those fantastic returns this year - a combination of high spring flows and excellent ocean conditions.
This whole idea of wild fish rescue using hatcheries is flawed, what needs to be done to rescue the wild fish is provide them wild habitat, and provide enough escapement of spawners to fill that habitat. If the habitat is gone and we are never going to get it back, then what exactly is the point of saving "museum piece" wild fish who will never have a place to spawn anyway? Now if we are going to take a dam out then great, let's try to save the genetics of the indigenous populations. But if not, forget it and convert it into a hatchery river and start requiring wild fish release - and banning fishing techniques that cannot accomplish this - on rivers that still have some habitat.
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The fishing was GREAT! The catching could have used some improvement however........