Overfishing

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