Up here we co-ordinate each species' open season with a best-practices for the future of the fishery in that region.

For example, Trout Season.  It typically opens the last Saturday of April.  This gives the fish a chance to spawn and allows anglers a chance to enjoy the best trout fishing of the year.     (You need to Login or Register  That's yours truly in the picture c. 1988.

The more stressed a species is, the stricter the regulations.  Sometimes this involves adjusting the season dates and even closing bodies of water.  Places that want to conserve a fishery will have the spawning grounds closed during spawn.  Sometimes this involves other restrictions like slot size limits, barbless, live bait, etc...