The consequences of catching to much fish

Consumption and production

trawlerWorldwide, we eat about 100 million tonnes of fish, that's an average of 13,5 kg (29,7 lbs) per person per year. The Japanese eat most of these fish: annually 72 kg (158,7 lbs) per person. We catch fish from the wild, or they are bred in a nursery. Both methods involve consequences for humans, animals and the environment.
Can fish be a good alternative for eating meat? That's a question a lot of people cope with, especially those who choose to eat less meat or none at all. To answer this question, the author of this article has investigated the consequences of fish-eating for humans, animals and the environment.


Industrial over fishing is the cause of the disappearance of fish and is a global problem. According to biologists of the Dalhousie University in Canada, the numbers of big (predator) fish, like marlin, tuna, codfish, halibut and swordfish have declined the last fifty years with 90% (3). The big fish species not only reduce in number, but also in size. Predator fish nowadays reach at their peak just about one fifth or half of the size they used to have. Some will never have the chance to multiply, according to the researchers. They point to the fact that many fish will become extinct if these sea raids will not be reduced with at least 50%.
Are all fish quota in bad condition then? No, the numbers of whiting, mackerel and herring are momentarily in good shape. For instance, the numbers of herring in the North Sea have returned to the level of the 1960's. This success in the herring population is due to a confluence of positive events: the large reduction of the herring catch in the late nineties and the big growth of young fish as a result of a favourable water temperature and sea currents.
dolphin wounded by fishermen?Every day, thousands of kilometres of driftnets are cast into the oceans. These nets are 'walls of death' to whales, dolphins and porpoises. The mammals often spot the nets too late and, when caught, are unable to escape from them. The animals cannot surface anymore to breathe. As a result, according to the International Whaling Committee (IWC), an estimated 300.000 whales, dolphins and porpoises (cetaceans) die as untargeted bycatch in fishing nets each year.

Healthy fish

  1. Herring
  2. Salted or smoked herring/male salmon
  3. Mackerel
  4. Pilchard (big sardine)
  5. Sardine
  6. Salmon
  7. Fresh tuna
  8. Trout
  9. Anchovy
These fish are healthy for us, because of the Omega 3 unsaturated fatty acids, which don't occur in mammal fat and which our body cannot produce itself. The fatty acids slow down blood clotting and reduce the blood pressure. Besides, they have a positive influence on various diseases and allergies. Recent studies of the Rush-Presbyterian St. Luke's Medical Centre in Chicago show that when consuming at least one fish a week, the chances of getting Alzheimer's disease are reduced with 60%.
A many heard objection against eating a lot of fish, is that fish meat often contains certain materials like heavy metals, dioxins, pesticides and broom containing flame retardants. These materials particularly build up in body fat. Because of this, especially fat fish can contain pollutions, depending on the place the fish has lived. In the past, because of this it was recommended not to eat more fish than once or twice a week. In the meantime, the quality of water in general has substantially been improved, so that this warning does not apply any more. We can conclude that eating fish once or twice a week is definitely good for our health. Eating more fish does not have an extra positive effect, but it does no harm, especially when one is eating various fish.

Pain, fear and stress experienced by fish

Can fish feel pain, fear and stress? A very important question, since this largely determines how we treat them. Not one scientific study has proven incontrovertibly that fish can experience pain, fear and stress. On the other hand, that does not only apply to fish, but to almost all animals. The problem is that the former mentioned feelings are subjective experiences and hence cannot be proven objectively: scientifically. Because of this, the (scientific) question whether a dog can feel pain, fear and stress, will probably always be unanswered. Despite the fact that the experience of pain, fear and stress cannot be established, it can be made plausible that certain animals do feel these emotions. In 1991, the Committee on Pain and Stress by Laboratory Animals formulated a shortlist of criteria to determine if (laboratory) animals can feel pain, fear and stress:
  1. The existence of anatomical and psychological resemblances to humans
  2. Stimuli that are unpleasant for the animal will be avoided
  3. It can be determined that painkillers show effect
German studies have shown that these criteria also apply to most fish. Furthermore, Scottish scientists recently revealed that, when injected in the lips with bee poison and vinegar, trout were acting differently. Not only the animals exhibited signs of stress, they also ate less and preferred soft food instead of hard pieces. Also other research shows it is likely that fish can feel pain, fear and stress.

Killing methods


Other than what people think, a fish does not die fast when taken out of the water. For example, herring choke only after more than 35 minutes, cod fish and whiting after 60 minutes. Sole and plaice take even more time to die; about 4 hours.


Stripping means that a fish is gutted alive. However, it does not die instantly from that. Herring, sole and flounder can stay alive for 10, respectively 30 to 35 minutes. Plaice can endure up to 50 minutes.

Choking and stripping

This killing method implies that fish are choking during 7 to 20 minutes, of which they don't die because the brain stays intact. After that, they are gutted alive. Then they will live for another 10 to 30 minutes until death occurs.

Neck cut

This killing method is used especially for eel. The eel is cut behind the head as a result of which the spinal cord is severed. The oxygen supply to the head however stays intact, as a result of which the animal does not die. Hence, when the animal is gutted afterwards, it may still be conscious.

Crawling to death

With this method, one sprinkles salt over the living eels, to get the slime of the skin. The eel moves wildly for a long time, trying to flee from the salt. The feeling of this salt bath on the eel's skin can be compared to burn wounds on humans. Above all, the salt also damages the gills. Obviously, a very painful method. When the eel finally stops moving, it has not died yet, but is still being gutted. Unfortunately, there are still lots of eel fishermen using these salt baths. With this method, more filets can be harvested, because there are less burn marks. At large companies, the eel are killed mechanically, with the use of electrical shocks. Sometimes, fish are not killed at all; the fishermen only cut off the parts that are used for consumption, after which the fish is thrown back. An example of this horrific method is shark fins. It is about time that the government intervenes and will issue demands for the use of (more animal friendly) killing methods.

The environment

Another important issue is the environment: just like with keeping other animals, also with breeding of fish a certain amount of manure development is involved. Studies from Norway show that fish nurseries are a very big source of phosphates and nitrogen. Compared to meat, most fish are an environmentally aware alternative though. Compared to land animals, fish need less food to grow, because they need less energy to move and they don't need to keep warm.

Fish for fish

A big part of the food for bred fish contains fish oil and fishmeal. Per kilogram bred fish, an average of 1 kilogram fish food (fishmeal) is needed. For this one kilo, two to six kilos of fish is needed (4,4 - 13,2 lbs). For example: to produce one tonne of salmon, 3.3 tonnes of sand sparling and whitebait is processed to fishmeal. For 1 kilo (2,2 lbs) of fishmeat, 1 to 3 kilos (2,2 - 6,6 lbs) of food is needed. Some fish species (like salmon and tilapia) eat plants as well as animals and maybe can be put on an entirely vegetarian diet in the future.

Biological salmon and trout

A growing number of nurseries is selling biological fish, mainly salmon and trout. We call the fish 'biological', but it has no EKO mark (Dutch mark for biological products) because the products are from abroad. The foreign marks are: Naturland mark from Germany and the Soil-association mark from the UK On the packages, other terms for 'biological' may be used, for instance the English word 'Organic'.

Dolphin friendly tuna

This is a label (no mark) of the fishery, that tells the consumer something about the way tuna is caught. When catching tuna, it is avoided that dolphins are being caught in the nets as well. Tuna and dolphins live together in the Eastern Pacific. It is no official mark.

Fish from the organic shop

Fish that is sold in organic shops has been caught without driftnets and does not contain preservatives or artificial aroma's. The catch has not been checked, there is no official mark. The shops may have cans of sardines, herring, tuna, salmon and mackerel.


Can eating of fish be a good alternative for eating meat? Yes, generally spoken, fish is healthier and provides a smaller burden on the environment. But, still a lot of wild fish is needed to breed fish. However, compared to meat, most fish can be an environmentally friendly alternative: for 1 kilo (2,2 lbs) of fish, in general less animal food is needed than producing 1 kilo of meat (11). The biggest problem is the number of fish being caught. Many (predator) fish are (locally) on the verge of being extinct. When for commercial reasons, it is decided to switch to other fish species and no action will be taken, it is quite possible that also other fish species will be threatened with extinction. Regarding animal welfare there are also a number of issues, still. Especially regarding breeding, catching and killing methods. Although the wellbeing of fish is still unclear, it is very likely that fish can experience pain, fear and stress from the way they are managed by humans.

logoThis page describes one aspect of the influence that man has on the quality of life of an animal. We wish to promote the (in other countries as well) growing of awareness, that freedom is also important for an animal. An animal is not a thing, but a being that has the right to quality of a natural way of life. If you want to do something to help animals, click here for our suggestions. If you appreciate our site, then please help spreading the articles.

Animal Freedom Foundation.
Author .

Our main articles in a book, via an overview or on a separate site.

Back to the top