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 NationsFood 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]
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.