Overfishing

Atlantic cod stocks were severely overfished in the 1970s and 1980s, leading to their abrupt collapse in 1992

Alaska pollock, another species of fish suffering from overfishing

This net contains about 360 tons of fish.

Altlantic menaden is only caught to make fertilizer and pet food.

Overfishing is catching too much fish. It is a type of overexploitation where fish stocks are reduced to low levels. It is a good example of what is good for the short term is not good for the long term. Also, what is good for some fishermen is not good for all of them (tragedy of the commons). The United Nations Food and Agriculture Organization estimated in a 2018 report that 33.1% of world fish stocks are subject to overfishing.^[1]

So much fish is caught that there are too few adults of certain species left. With cod, for example, the greatest production of eggs is from large females. But these are caught, the average size of spawning females goes down. Eventually this gets so that the production of eggs is significantly reduced. The artificial selection of large fish has gradually reduced the size of mature females.

The Northwest Atlantic cod has been regarded as heavily overfished throughout its range, resulting in a crash in the fishery in the United States and Canada during the early 1990s.^[2] Sometimes, the fishing industry can ruin itself by overfishing. The collapse of the herring industry in Monterey, California is a good example.

Consumers can get information about the conservation status of the seafood available to them.^[3]

Examples of overfishing

Examples of overfishing can be found in places like the North Sea, the Grand Banks of Newfoundland and the East China Sea.

Tuna has been caught by people in the upper Adriatic for many years. Increasing fishing has stopped the large schools of little tuna fish from migrating into the Gulf of Trieste. The last major tuna catch was made in 1954.^[4]
The anchovy fisheries in Peru crashed in the 1970s after overfishing and an El Niño season reduced the number of anchovies from its waters.^[5]
The fish in the Irish Sea, the west English Channel, and other places have become overfished so much that it has almost collapsed.^[6]
Blue walleye became extinct in the Great Lakes in the 1980s. The number of blue walleyes collapsed, because of a combination of overfishing, eutrophication, and competition with introduced rainbow smelt.
Sharks and rays: The global amount of sharks and rays has reduced by 71% since 1970. Because of this made sharks and Ray's are almost extinct.^[7]

Preventive measures

There are many ways that have been suggested to stop overfishing. They are:

Governments from around the world should make and enforce laws that prevents overfishing
Subsidies should be removed from deep sea fishries to discourage deep sea fishing
Aquaculture should be encouraged because it is sustainable
Better fishing techniques like using different gear types depending on the type of fish and habitat.
Avoiding fishing in places where fish lay eggs may allow fish stocks to grow by giving adults a chance to reproduce.
People should be taught about the dangers of overfishing.

Overfishing Media

Fishing down the food web
Darker shades mean less overfishing, lighter shades mean more overfishing. EPI scores range from 1–7; 7=highest level of overfishing.
Overfishing can deplete key reef species and damage coral habitat. Coral reef fish are a significant food source for over a billion people worldwide.
Overfished US stocks, 2015
The Traffic Light colour convention, showing the concept of Harvest Control Rule (HCR), specifying when a rebuilding plan is mandatory in terms of precautionary and limit reference points for spawning biomass and fishing mortality rate.
World capture fisheries and aquaculture production by species group, from FAO's Statistical Yearbook 2020
The Chinese paddlefish, once common to the Yangtze River, has gone extinct due to overfishing and dam construction