"Roving Bandits" Depleting Fisheries, Experts Say

Anna Petherick
for National Geographic News
March 16, 2006
Improved technologies—faster boats, better refrigeration—have
allowed today's fishers to quickly roam across every corner of the seas.

No longer limited to their local waters, some marine-life traders are overharvesting species in regions where sustainability laws don't exist faster than regulators can respond.

Now 15 researchers from around the globe have joined forces to draw attention to the damage to fisheries caused by these "roving bandits."

The traders are central drivers in the overexploitation of the world's oceans, destroying local stocks and evading authorities, the researchers say.

"I really want to convey a sense of urgency. We don't have much time left to prevent a massive wave of marine extinctions" caused largely by the marine-life traders, said biologist Boris Worm of Dalhousie University in Halifax, Canada.

Due to rapid globalization, people buying and selling marine life-forms can travel almost anywhere in the world within a day.

Many species and habitats that were previously too inaccessible to be economically viable targets for fishers are now open to exploitation.

For example, large tropical fish from remote island reefs are temporarily stunned with cyanide and flown alive to Hong Kong restaurants, where diners can select their meals as their fishy food swims in a tank.

Roving Markets

In their policy paper, which appears tomorrow in the journal Science, the group of ecologists and social scientists describe how globalized markets mask the damage that roving bandits inflict on the world's fisheries.

Even though the market supply of a marine species may remain the same over time, its source often jumps geographically around the world as buyers and fishermen exhaust one local fishery and move on to the next.

International markets eventually show evidence of the depletion, but only when the last main source of a species is impacted.

A strong example of this effect is the harvest of sea urchins used to make sushi—called uni on restaurant menus.

Researchers have created a map showing the increasing ranges where fishers have harvested the sedentary creatures since 1945 (see the map).

Japan, the only major market for urchins, keeps thorough records on where each catch came from.

Jim Wilson is an economics professor with the School of Marine Sciences at the University of Maine in Orono.

"Because of the peculiar nature of the market and the animal, you can see very clearly when and where this spatial expansion has occurred, moving from resource to resource as depletion takes place," he said.

Following the collapse of the cod fishery in Maine (see map) in the mid-1980s—which removed the urchins' main predator—the local population of green sea urchins grew rapidly.

In 1987 an unregulated urchin harvest began off the Maine coast.

Within just six years of targeting by the sushi market, the region's urchin population was devastated.

Deep-sea fisheries take even less time to disappear than coastal populations, Worm says.

Fishers often work a chain of deep-sea mountains for usually no more than two or three years before they destroy the local population of fish and move on.

"People are just beginning to realize what is down there, and it is being scooped up indiscriminately by people who act exactly like roving bandits," he added.

Common Good

Economist Mancur Olson originally coined the term "roving bandits" as part of an argument about the origins of government.

He imagined a world full of roving bandits, who arrive in one place and take what they can before moving on.

But if the bandits are forced to stay in one place, they will "have to rethink the game entirely," Wilson said.

"I think of it in terms of Vikings roaming around, looking for places to raid and pillage," he added.

"If one group of Vikings suddenly found themselves stuck in one place because their boat was wrecked, all of a sudden they'd be faced with the problem of how do they treat the local people."

The study team agrees that emphasizing the common good of protecting resources is one way to combat roving bandits.

"I think we are neglecting the importance of the local level backed up by national laws," said University of Manitoba, Canada, professor Fikret Berkes.

Local people need property rights over local resources to provide them with incentives to conserve those resources, he added.

Tropical reef researcher Terry Hughes, who convened the group of experts, believes part of the solution lies with the consumer.

People can "refrain from eating species which are threatened or those that play a particularly important role in the functioning of an ecosystem," he said.

Disrupting the population of a single marine species can have dramatic consequences on the whole ecosystem.

"It's like hitting one of the main distributor lines in a power grid," Worm, the Dalhousie University biologist, said.

"When you pull out nodes or cables from the power grid at random, sometimes you will hit a really important one, and the lights will go out all over the place."

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