The decision to keep a fish should be made carefully, and ideally before even starting to fish. If it's certain that no fish caught will be eaten (and it's not a tournament where fish are kept in an aerated livewell that will insure their survival) then every fish should be released immediately. Once you’ve made that important decision, there are few things you can do to be “gentle” on the fish
that is being put through the stress of being caught.
1. Unhook easily! You don’t need barbs on your hooks if you are catch and release fishing. Use barbless hooks and avoid treble hooks. You can pinch down the barb with pliers, and cut two hooks from the treble hook if needed. Have long nosed pliers or a similar tool on hand to remove the hook if necessary.
2. Lips Only! Avoid situations that encourage a fish to “swallow” the hook, and by that we mean ingesting the lure so deeply (maybe not completely swallowed) that severe injury is likely. Use unscented artificial lures or flies, and detect the strike quickly so the fish doesn’t have time to ingest the lure and hook deeply. Sometimes it will happen, and then you will need the pliers mentioned above.
3. Don’t Touch! Use a landing net, keep the fish in the water, and avoid handling the fish. You can take a photo of the fish in the water in the net. You don’t need to hold and squeeze the fish. If you don’t have a net, keep the fish in the water and touch it with wet hands only. If you’re using a barbless hook you shouldn’t have to touch the fish at all!
4. No Stress! Pick the time and place you fish. Be aware of conditions that cause stress on the fish – hot weather, low water flow, and retrieving fish from deep water. Minimize catch and release fishing in these situations. Take a book to read on the bank!