Yes, it's possible that a 30 lb. buck my be the brother of a 12lb. hen that is making a second trip up the river.

Given that less than 10% of our fish are repeats ... I would venture a guess that probably about 99% of the boys are 1st timers. Smalma may be able to confirm / deny this number.

Food certainly plays a role, but it's the number of years in fresh / salt / spawning runs that is dicated by genetics that plays the biggest role in how big the fish is.

One of the very reasons IMO that I don't believe we can manage them like salmon ... life history possibilities are all over the map!