In the upside down position a fish seldom struggles. If you must handle a fish, wet your hands first to avoid removing the protective slime on the skin of the fish. Never squeeze a fish around the middle or touch its gills. Internal injuries and bleeding from too much finger pressure are common causes of death in released fish. Never let a fish flop around on the rocks or in the boat.
Most fish die because they have been released before they have had time to recover from the fight.
No fish should ever be thrown back into the water. To revive a fish prior to release, hold it in the water just above the tail. Keep it upright facing into the current. Push the fish forward and back slowly until the fish is ready to swim strongly on its own. This may take a few minutes.