Where do you live again?
The fish I speak of are very regulated and studied for a reason. The Alaska game and fish post this type of information all the time for the Sport Fisherman. I didn't make this up!
Example being. A bad forest fire in Alaska will produce lots of airborne ash etc. This ash will fall to the ground and cover the river beds where the fish eggs are, in return having a low fish number count of these same fish hatchling heading back up the same stream in which they were born to spawn, 7 yrs earlier. MOST!
So this is why they study these fish and their habitats like they do to make sure they are not overfished, in case of a low fish number count back up the rivers to spawn.
We don't get to fish if these numbers are not met each year. They will close the fishing off to both sportsman and commercial fisheries, game over till next year kind of a deal!