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The life of the Earth’s oceans, once thought to be inexhaustible, is anything but. In fact, a 2006 study predicted that if current trends continue, we may see the end of wild-caught seafood by 2048.

That warning got a lot of play in the popular press, but Larry Crowder, the Stephen Toth Professor of Marine Biology at the Duke Marine Lab, says no one can pinpoint the exact date of such a disaster.

“I’m uncomfortable with extrapolating any trend out 40 years,” Crowder says. “But if we don’t change the way humans relate to oceans, extreme things could happen.”

He and others in the Nicholas School of the Environment and Earth Sciences are trying to turn their years of study on the current and future states of the oceans into sound policy decisions that would allow humans to continue harvesting the ocean’s bounty.

People have taken food from the oceans for thousands of years — until very recently without any rules, points out Michael Orbach, a professor of the practice of marine affairs and policy at the Marine Lab. He thinks it’s past time for that to change.

World Fisheries Exploited, View Larger Map
The U. N. Food and Agriculture Organization estimates that half of the world’s marine fisheries are fully exploited, and a quarter are over-exploited or depleted. Source: The State of World Fisheries and Aquaculture, 2006

As a cultural anthropologist, Orbach combines his knowledge of science and human values to build policy. “I’m the guy who wants to fix the problem and not just dwell on it,” he says.

“The resources of the ocean have historically been considered common property,” Orbach says. “One of the results is we have wild overcapitalization in all fisheries. Whoever wants to go out there and fish can go.” Most coastal countries claim economic control of the ocean 200 nautical miles off their shorelines. But that still leaves 60% of the ocean an unregulated free-for-all.

While many countries now have regulations for specific fisheries, that’s not much help for species such as the bluefin tuna that cross borders.

As fishing technology has become ever more efficient, populations of both target fish and bycatch — the unintended casualties among other species — have been decimated. Two industrial-scale technologies in particular are causing unsustainable damage. “Longlines” are miles-long baited lines that snare turtles and birds as well as fish. “Bottom trawlers” are ships that scrape the ocean bottom indiscriminately, scooping up fish and other organisms and wiping out sea floor habitats. (See slideshow)

“We’re behind the eight ball,” Orbach says. “We let technology and this open access go way too far down the road; now we’re playing catch-up.”

Orbach and Crowder say there’s no simple solution. But for starters, they agree that too many fish are being taken. “Ultimately there needs to be some limit on how much fishing effort there is,” Crowder says. “That’s resisted by some in the industry. But in fisheries around the world where they’ve put in total allowable catches, those fishermen are doing fine economically.”

Maine’s lobster fishery, which collapsed in the 1930s, is a prime example of the benefits of this kind of self-discipline. Today the fishery is thriving under a combination of state regulations on size and locally determined harvesting quotas. The catch increased from about 10 million pounds in the 1930s to around 60 million pounds by 2006. It nearly quadrupled from 1984 to 2004 as stocks rebounded.

In addition to focusing on particular species, quotas also should be based on knowledge of marine ecosystems, says Crowder. A healthy ecosystem has multiple species filling each role. When several species are lost, the ecosystem loses resilience.

“When only one species is playing a primary ecological role, if that species is lost even temporarily, there is a big impact on the system,” Crowder says. For example, several herbivorous fish species in the Caribbean were fished out in the 1970s, leaving only one type of urchin to eat the algae that grows on coral. When a disease wiped out most of those urchins, algae overran and killed much of the coral. If the herbivorous fish had still been around, the urchin disease would have killed only urchins, not coral. Bottom line, says Crowder: “More diverse systems behave better.”

One strategy for maintaining diversity is establishing marine protected areas, where fishing is completely off limits. These areas allow marine organisms to flourish and recover within their boundaries to reproduce and spread from there.

A related idea is the marine managed area, where all ocean uses—fishing, mining, recreation—are managed together with the goal of balancing economic and environmental needs.

Orbach is starting on a five-year project to establish, monitor and compare marine managed areas in Belize, Brazil, Panama and Fiji. The project, funded by the Gordon and Betty Moore Foundation through Conservation International, will work with citizens of each country to plan each area. Scientists will establish a baseline of biophysical, economic and socio-cultural data for each site, and monitor the data over time to evaluate the effectiveness of the marine managed areas.

Nobody’s actually done this before,” says Orbach, who is coordinating the socio-cultural research for the project. “A lot of the time, people just make a decision to establish an area and nobody documents the results.”

Orbach points out that even for those who don’t eat fish, there are plenty of reasons to care about the ocean and its inhabitants. The ocean plays a key role in the carbon cycle, the water cycle and the climate.

But for Orbach there is more. “I am a surfer and a sailor and a fisherman,” he says. “I want people to be out on the water; I want them to experience the ocean. Wilderness experiences are not just pretty—they are good for your soul.”

Mary-Russell Roberson is a freelance writer in Durham, NC.