Animal welfare impact on captured fish
There are several types of fishing by hook and line. This section refers to fishing with hand gear in which the fish is landed soon after capture. If this type of fishing is done from a moving boat, then it is called trolling.
As with any hook and line fishing method, fish are caught when they snap at baited hooks which then become embedded in the fish’s mouth or elsewhere.
Hooking is stressful to fish and causes an alarm response in which they will struggle to become free. This can lead to severe exhaustion. Hooking fish causes injury which is sometimes severe, as discussed in trolling.
One study found that the response by carp to hooking was similar to that for other stimuli likely to cause pain and fear (e.g. electrical stimulation of the mouth of a free-swimming fish), indicating that hooked fish do suffer fear and pain. According to Professor Donald Broom, University of Cambridge:
Sometimes fish are gaffed (i.e. impaled on a hook) to bring them abroad and this is likely to cause considerable pain.
Sometimes live fish are used as bait. This adds hugely to suffering caused in this method.
Conservation groups consider rod and line fishing to have low levels of bycatch compared to other major fishing methods. Bycatch fish can be released quickly.
Levels of hooking injury, and the survival chances of released bycatch fish, are affected by the type/size of the hook/bait and the method by which the hook is removed.
Barbless hooks and circle hooks have been recommended for “catch and release” fishing. In circle hooks (in which, as the name denotes, the shape is more circular than the J-shaped hook) the point is turned inward, which can increase the likelihood the fish will be hooked around the mouth rather than in the stomach, throat or vital organs.
Removing hooks by hand, in a way that tries to take the hook out the same way it went in, causes less resulting injury than removal by automatic means that tear the hook out. In a study of Pacific halibut caught as bycatch in long line fishing, careful removal of the hook by hand more than doubled the survival chances of released fish compared to removal by automatic hook strippers.
Many factors affect the ability of a fish to cope with being hooked. These include the species and size of the fish, the temperature and depth of the water, the type and size of the hook and bait and how the hook is removed. Fishing at warm temperatures and at greater depths (causing the fish to experience sudden changes in pressure) can reduce survival chances.
Measures to reduce suffering in rod and line fishing
The following measures, combined with humane slaughter immediately the fish is landed, would improve the welfare of fish caught in rod and line fishing:
|Reducing the suffering in rod and line fishing:
Reduce suffering of bait fish
Keep the duration of capture short
Reduce the numbers of bycatch animals
Reduce death rates for discarded bycatch fish
Reduce stress and injury during capture
Reduce stress and injury during landing