Why did cod stocks near Newfoundland become severely depleted in the late 20th century?

The collapse of the Atlantic cod population near Newfoundland and Labrador was primarily driven by overfishing and government mismanagement.1

Beginning in the late 1950s, the introduction of industrial-scale trawlers, advanced sonar, and onboard freezing capabilities allowed for unprecedented harvest levels. This rapid intensification of fishing pressure led to a catastrophic decline in stocks, a classic example of the tragedy of the commons, where the incentive to maximize short-term gain resulted in the depletion of a shared resource.1

The crisis was exacerbated by flawed population models used by the government to set fishing quotas. These models relied on overly optimistic assumptions regarding cod reproduction and survival, failing to account for environmental variables like climate and food availability. Consequently, the government permitted excessive fishing pressure even as the population plummeted. By 1992, the stock had crashed to less than 1 percent of its original size, forcing the Canadian government to impose a commercial fishing moratorium.1