I was told by one of the bios. on the Kalama that the reason that not all fish are clipped is so that they can make sure they get back some fish. Check out the fish that return to the hatchery and you will see some fish with all their fins. A good example is the summer kings from the Wallace hatchery. Go check the creek below the weir and see if some of those fish have all their fins. The summer kings are all hatchery.