Just did an interesting test, I cut 100 pieces of small paper about an inch square. 50 I marked W and 50 I marked H, I then put them in a small plastic grocery bag and shook them up.. I then did a blind grab one at a time, I kept each H and put each W back intill I reached 50 times..If these were coho and I handled 50% of the run I would have kept 14 and with a 22% mortality rate I would have killed 8 wild..I'll try it again in the morning a few times to see if it changes much..