Fishes

Scientific research conclusively shows that fishes feel pain. Nociceptors are nerve-cell endings found throughout the bodies of humans and other animals and on the skin of fishes, which initiate the sensation of pain. Researchers from the University of Edinburgh have studied the role of nociceptors in the behaviour of fishes in response to painful stimuli.

The researchers found that fishes learn to avoid unpleasant stimuli such as electric shocks and the piercing of their lips by sharp hooks. This suggested that fish behaviour was adversely affected by painful experiences and that these behavioural changes were not simple reflex responses.

Salmon need to be regularly sorted by size and separated, as trapped bigger fishes will bully smaller fishes. This repetitive manipulation in fish farms is a significant cause of stress and pain for fishes. Other invasive practices include vaccinations, loading, transportation and breeding techniques in which the males are stripped of sperm and the females of eggs.

Farmed fishes can suffer high mortality rates from injury and disease, and they are also vulnerable to predators and other hazards. In one incident in 2010, thousands of fishes were killed when jellyfish floated into a salmon farm. Attacks from seals are also an issue on New Zealand fish farms.

There are many types of commercial fishing, but by far the most destructive method is trawling. Trawling involves dragging huge nets through the ocean, scooping up everything in their path. This results in the wasted lives of many non-target species, who are thrown back into the sea, injured, dead or dying.

Bottom trawling is particularly destructive, as it involves dragging heavy nets across the seafloor. The nets destroy entire marine ecosystems, depriving many species of food and shelter. Bottom trawling is one of the most wasteful fishing methods, due to the high percentage of non-target species caught.

Non-target species caught in fishing nets are referred to as bycatch. Every year countless New Zealand animals, including sharks, turtles, dolphins, sea birds and sea lions, die needlessly as victims of bycatch or as a result of being caught in discarded fishing equipment. Some of these animals are endangered species, such as Hector’s and Māui dolphins, Antipodean albatross and yellow-eyed penguins.

A 2019 report by Greenpeace revealed that 640,000 tons of fishing gear is dumped into the ocean each year ‒ the equivalent in weight to more than 50 thousand double-decker buses.

This dangerous discarded fishing equipment is known as ‘ghost gear’ and is a significant contributor to the plastic rubbish in our oceans.