When you're about to land the fish, avoid removing it from the water. Keep it in enough deep water to protect it. Do not let the fish flop in shallow water over rocks and never on dry land. Cradle the fish gently with two hands, one supporting the belly and the other just ahead of and underneath the tail section. Keep your fingers out of and away from the gills.
Gills are delicate and full of blood vessels.
Once a fish begins to bleed from his gills, it is likely to die. Pressure against a vital organ will often prove fatal. Use soft wet gloves or at least wet your hands before handling a fish. If you wish to photograph a fish, have a camera ready and take the picture quickly. Get someone else to take the picture or hold the fish.