For anglers who go fishing often, a bag limit is not necessarily a target. Catching a feed of fish with perhaps a few to give away makes for a satisfying day on the water.
But how a fish is handled can make a difference as to whether it survives the experience. The body of a fish is designed to be supported by water. So when it is held up in the air it can be injured easily. Internal organs can be damaged by squeezing or by the impact of thrashing on hard surfaces.
So the ideal solution is to not remove the fish from the water at all but to reach over the side of the boat and flick the hook out with needle-nosed pliers or similar hook-release tool. If a fish has swallowed a hook, it is better to cut the line close to the mouth rather than tear out the hook or use a gob stick.
It is often surprising just how fish will survive with a hook inside them and sea water soon rusts metal, which can be passed through the system.
The eyes are not designed to cope with direct sunlight, which is another reason for keeping the fish in the water.
Don't hold fish upside down by the tail or support them with a hand under the gut. Small fish can be lifted by the line if hooked in the mouth and a net with a soft mesh is ideal.
Fish scales have a layer of mucous which protects from infections, and this can be damaged by handling them with dry hands. Ideally a wet cotton glove or towel, or at least wet hands, should be used. If a fish has to be held, placing the hands under the throat and tail are recommended.
Never hold a fish by inserting fingers in the gills, as these are delicate and damaged easily, or in the eye sockets.
Large fish like hapuku and kingfish can be lip gaffed by inserting the gaff hook through the skin just behind the lower lip, and the high proportion of kingfish that are recaptured after being tagged shows that they have a high survival rate.
Fish brought up from deep water also suffer from their internal air bladder expanding, and this can be punctured by inserting a needle in the side of the gut. In Australia some fishermen use a heavy sinker on a separate line with a barbless hook, which pulls the fish back to the seabed, and a flick of the line will release it from the hook.
Barbless hooks are common in many sport-fishing situations where the fish is always going to be released, like fly fishing for trout or saltwater fly fishing for bonefish, or casting poppers for giant trevally in the tropics. This makes hook removal fast and easy, and reduces damage.
The best way to protect small fish is to not catch them at all, and with snapper fishing large hooks and baits are less likely to be swallowed. If plagued by small fish the best solution is to shift to another spot.
The minimum legal size limits are set to allow fish to breed at least once before they can be caught, and it is up to all fishermen to be conversant with the rules.
Fish are measured from the tip of the nose to the V in the tail, but many anglers adopt the view that if a fish has to be measured because it is close to the legal length then it is too small to be taken.
But when all is said and done the only certainty is that a fish has a better chance of living if it is returned to the water in any condition, rather than being put on ice in the fish bin.