Attached is an article I wrote several years ago and is still relevant.
On average size another thought. Two things control the catching of wild
salmon. Time of year and net sizes. Net sizes are designed to let
small fish escape therefore we selectively kill the large and presumably
faster growing fish. Fish lay eggs in numbers in proportion to their size.
Have we selectively culled large fish and therefore the fish we protect are
actually laying few eggs and breeding a smaller fish which in turn will
aggravate the situation?