Problems with overfishing include the loss of entire ecosystems and species as well as the loss of food supplies resulting from the lack of fish. Another problem with overfishing is that it decreases the top predator populations and causes an imbalance in the smaller populations of marine life.
Overfishing occurs when fish are caught faster than they can breed and rebuild their populations. Overfishing causes fishing industries to collapse when fish populations diminish. For example, in Newfoundland, Canada, the cod fishing industry was decimated in 1992 when the fishing season came and no cod showed up. Over 40,000 people lost their jobs, and the marine ecosystem suffered.