Dispatching a fish: doing it properly, or not doing it at all

SPIKING — driving a spike into the brain, the practice usually called iki jime — appears among the methods recommended in the international literature, and is used commercially for exactly the fish anglers most want to keep in good condition. It demands that you know where the brain is in the species in front of you, which varies more than people expect, and it is a technique to learn on fish you have already stunned rather than to attempt first.

CONFIRMING A DISPATCH WORKED IS HARDER THAN IT LOOKS, AND THIS IS WHERE MOST GUIDANCE OVERPROMISES. The review of wild-caught stunning is explicit that "visual/behavioural indicators alone cannot always be relied upon as accurate measure of consciousness." The eye-roll check that circulates in angling writing — rotating the fish and watching whether the eye tracks — is a reasonable field check and it is not proof.

The practical consequence is not to abandon the check. It is to treat a doubtful result as a reason to strike again immediately, rather than as a reason to conclude the first blow worked. The cost of a second blow to a fish that was already insensible is nothing; the cost of assuming is borne entirely by the animal.

AND THE UNCOMFORTABLE FINDING IS PUBLISHED HERE TOO. The same review reports at least one wild-caught species in which asphyxia produced BETTER product quality than percussive stunning. It is one finding rather than a pattern, and it is worth stating because the honest case for humane dispatch is a welfare case. Dispatching well usually improves the fish as well. It is not guaranteed to, and a page that promises the two always coincide is arguing from convenience rather than from evidence.

A fish out of water is not slowly losing consciousness in the way the phrase suggests. Its gill lamellae collapse together in air, so gas exchange stops while the animal is fully alert; it responds by struggling, which consumes the oxygen it can no longer replace. The struggle is what produces the lactate and the depleted muscle energy stores that spoil the flesh, so the welfare failure and the quality failure have the same cause.

On ice, the fish is additionally cooling, which slows metabolism and prolongs the process rather than shortening it. That is the specific reason the review of wild-caught stunning treats "asphyxiation (in air or ice)" as one category: putting a live fish straight into an ice slurry is not a kindness with a chilling bonus attached.

None of this is an argument against ice. It is an argument about sequence. Kill first, then chill — and the chilling record explains why the second half is as urgent as the first.

Most fish caught in Britain and Ireland are returned, and for those the whole of this record inverts: the objective is the shortest possible interruption rather than the fastest possible death. The catch-and-release literature is consistent about which variables matter — air exposure, handling time, hook damage and water temperature — and consistent that they compound rather than adding up.

The practical link between the two halves is the decision itself. A fish held 'while you think about it' is being subjected to the release-mortality variables and the dispatch delay at the same time, and getting the worst of both. Deciding at the net, before the fish is out of the water, is the single change that improves both outcomes.

Where a fish is deeply hooked and bleeding heavily from the gills, the decision has often already been made by the hook. Cutting the line and returning a fish that will not survive is a worse outcome than dispatching it, and where the rules permit keeping it, that is usually the honest choice.

Whether a fish may be killed at all depends on the water, the species and the season. Many fisheries are catch-and-release only, many species carry size limits or closed seasons, and some are protected outright. Check the rules for the water you are on with the fishery, the licensing authority or the relevant agency before keeping anything.