- Roughly a quarter of the 120 million tons of seafood that humans catch every year is stolen from countries' waters or caught with outlawed methods.
- Vessels are bigger than ever, and fishing techniques more effective. Consumer incomes are higher than ever, around the world.
- The world's fisheries are endangered by illegal actors who flout rules designed to protect species.
People have been taking fish out of the sea for about as long as people have existed at all. But criminal fishing has never posed the threat that it does today.
The growing problem goes by the clunky name of "illegal, unreported and unregulated fishing," and it has put whole swaths of the world's fisheries in danger. Roughly a quarter of the 120 million tons of seafood that humans catch every year is stolen from countries' waters or caught with outlawed methods, according to marine biologists.
Vessels are bigger than ever, and fishing techniques more effective. Consumer incomes are higher than ever — around the world. And the mechanisms and infrastructure of global trade make it possible to ship catches further, more easily.
The problem is criminals who flout the regulations that legal fleets must obey. Sometimes, illegal perpetrators use small boats, slipping from their own waters to poach other countries' fisheries. Other times, the fish thieves use huge, industrial vessels that scoop up vast stretches of water, killing everything in their nets.
The biggest outfits work in fleets, dropping their catches onto tremendous, refrigerated mother ships. That practice, called "transshipping," lets fishing boats stay at sea, sweeping up marine life, for years at a stretch.
Scientists warn that, unchecked, overfishing will eradicate whole species, and could within a few decades contribute to a total collapse of the world's fisheries. But fishing grounds from Asia to Africa and beyond are already cleaned out.
Fish are swept away for sale in wealthier, far-away markets, such as China. Beijing helps its fishing fleet — the world's biggest — range far across the globe by giving government subsidies based on boat horsepower, according to risk analysis firm Stratfor and others.
Shadowy boat owners come from nations all over the world, however, even from countries like Thailand that are trying to combat fish pirates.
In the meantime, traditional oceangoing villages can't compete. Fishermen lose their livelihoods. Struggling nations are stripped of economic resources. Governments are robbed of tax revenue. People lose their main source of protein.
And there's another, almost unfathomable human cost: Often, these illegal fishing operations enslave their crewmen. They trick impoverished job-seekers aboard. They hold them against their will for years. And they may sell them, abuse them, or even kill them with impunity.
There are many reasons why catching the bad guys is so hard.
First, the oceans are vast almost beyond imagining. Even if authorities know where illegal fishing is happening — and they're inclined to intervene — it could take them several days to get to the scene.
Second, it's often unclear just who the "authorities" are. The United States polices its own marine waters, and so do other wealthy nations. But there is no police jurisdiction on the world's gargantuan, open seas. Many countries can't afford to operate ships or pay crews to watch over even their own waters.
Finally, it's hard to determine who the real perpetrators are — even when violating boats are identified. Illegal fishing vessels change names and intentionally obscure their ownership.
A vessel at sea may be owned by a person in one country, fly the flag of another country, be captained by someone from a different country, and put its cargo ashore in yet another — for processing somewhere else, and sale somewhere beyond that.
And there's nothing illegal or inherently unethical about a globalized fishing industry, or practices such as transshipping that support it.
But the practices that underpin global shipping can become problems in their own right, such as when criminal boats dump their cargoes onto mother ships, where illegally caught fish may get mixed in with catches from other boats — including the legal ones.
Those illegal catches, blended in with the rest, then become untraceable.
WATCH: "Oceans of Crime" premieres in the U.S. on Saturday, February 17 at 8 p.m. ET/PT. It premieres in Asia starting on Monday, February 19 at 1 p.m. SIN, and in Europe on Monday, February 19 at 1 p.m. CET.