Illegal fishing is a major threat to the sustainability of the world’s fisheries. Some estimates are that illegal and unregulated fishing causes annual financial losses of up to $23.5 billion worldwide and accounts for up to 20 percent of all of the wild marine fish caught globally. In some parts of the world, the situation is even more dire. For example, fisheries scientists estimate that illegal fishing accounts for up to 40 percent of fish caught in West Africa.

Pressure on the world’s fish stocks is at an all-time high. Fishing fleets utilize modern technology and massive vessels to fish in places that until recently were out of reach because they were too deep, remote, or dangerous to exploit.

Fleets now pursue and catch fish in virtually every part of the world’s ocean. Massive processing vessels—floating factories that process, freeze, and transport fish in huge quantities—allow fishing vessels to offload catch at sea and continue fishing with alarmingly little downtime. The result is what some call “the last buffalo hunt”—too many fishing vessels chasing a dwindling number of fish that have nowhere to hide.

Most industrial fishing operations act within the law, but some take to the seas fully intending to steal fish. They do this in various ways, including failing to report catch, using illegal fishing gear, fishing without licenses, and even painting new names on their vessels while at sea to avoid detection by authorities. And they do it wherever they think they can get away with it, both within the exclusive economic zones (EEZs) of coastal states and on the high seas. In many cases, the theft is made easy by patchwork regulation of fishing areas and weak enforcement at sea and in ports.