"not understanding that his 8% mortality rate because he was very skilled at reviving released fish vs 20-50% of the average joe still tallied 76 dead native fish"

That would mean the angler caught around 83 natives for the year. Know anyone who has caught 83 natives in the last year? I don't. Let's say instead that the same angler caught 10 natives for the year, which still ain't bad. At 8% mortality he killed one of those 10. For the death of one native the angler got to fish all year. He got to make more than one trip to the coast with his buddies. He got to fish for natives in more than one river. He also spent his money all year on gear, gas, food, lodging, etc. Had he whacked the first one his fishing would have been cut short for the year, and his economic contributions would have ended.