In the late 1980s, things were not going well for the coral reefs at Jamaica's Montego Bay Marine Park . Overfishing had taken out a lot of the fish that eat algae, and algae were taking over the reef. "It was a classic case of ecosystem decline," human geographer Joshua Cinner says. He arrived in Jamaica in 1996 as a Peace Corps volunteer after graduating from the University of Colorado, Boulder , with a double major in environmental conservation and geography. He was particularly interested in parks and preserves.
He'd landed in the middle of a war. Lobbying by tour operators and others got spearfishing, one of the main culprits in overfishing, banned in the park. The ban did not go over well with local people. "All the park equipment got vandalized. We had park rangers get threatened; their families got threatened at spear point," Cinner says. Spearfishing equipment is cheap and you don't need a boat; men who do it are generally poor and are fishing as a last resort. "The cultural lens through which the fishermen viewed this issue was of struggle in a post-slavery society, of the rich, predominantly white expatriates making a law that oppressed the poorest of the poor locals to benefit the wealthy."
Special Issue: Changing Oceans
This article coincides with a special issue of Science devoted to the topic of changing oceans. You can view the ocean-related articles  in the table of contents of the 18 June 2010 issue.
The conflict got Cinner thinking about how conservation really works. "It wasn't really about the ecology," he says. "Making conservation work in Jamaica had a lot to do with understanding the local culture and people." It also opened his eyes to the role oceans play. "The ocean is often viewed as an open-access resource. That extra layer of complexity interested me," he says. "Land can often be private property," but "the ocean is typically viewed as free for anyone to fish in, for anyone to swim in and use."
Now a senior research fellow  at James Cook University  (JCU) in Townsville, Australia, Cinner studies how coral reefs and people interact in a vast swath of the Southern Hemisphere. "People often have trouble understanding why a social scientist is involved because they think it's the realm of the marine biologists," he says. But it makes sense in the context of coral reefs, which are host to dozens of species of fish that provide food and income for nearby villages. "You don't manage fish. Fish swim and they do their own thing. You manage people. Managing ecosystems is really about managing people and understanding what motivates them and their behaviors."
Joshua Cinner visits a market in Madang, Papua New Guinea, in 2002 for research on the impacts of markets on fisheries.
After his stint in the Peace Corps, Cinner followed his interest in oceans at the University of Rhode Island, earning a master's degree in marine affairs , a combination of anthropology and policy. For his degree, he spent 2 months in a village in the far east of Mexico, near the border with Belize. He hung out on fishing boats, watching how the fishermen worked and pitching in with the work. "I think they liked me because I was free labor," he says. He designed a questionnaire for the fishermen about their lives and found, unsurprisingly, that local people, many of whom struggled for basics such as food and shelter, did not put the state of the environment high on their list of worries.
His work led him next to Indonesia and Papua New Guinea. Zoologist Tim McClanahan  of the Wildlife Conservation Society  was hiring a team to look at the ways that villages there have traditionally managed fisheries. For example, some villages keep their coral reef closed to fishing most of the time, then do a lot of fishing at once. "When they actually go in and harvest fish, it's a madhouse," McClanahan says. Other villages keep a fishery open for a few years, then close it for 9 months or so. McClanahan set out to determine whether these strategies were good for the fish.
Cinner and the other researchers spent a year traveling across Indonesia and Papua New Guinea, living in coastal villages for weeks at a time to get a first-hand look at the villagers' fishing practices. In one village in the Manus Province of Papua New Guinea, fishing a particular section of the coral reef is forbidden for all but a few days of the year. The team arranged to be there for one of the rare days when fishing was allowed. Villagers set up nets and drove everything into them, harvesting 210 kilograms of fish.
Cinner's team measured the fish being caught and found that they were larger than fish caught in other parts of the reef -- just what the locals had told them. That suggested that partially closing the area gave fish a chance to grow bigger, one of the benefits marine biologists have suggested for totally banning fishing. "I think there's a lot of preconceptions that [marine protected areas] that are fully closed are going to work a lot better," Cinner says. But he thinks managing the way that village does might work better in many places, because villagers will be more likely to follow the rules if they see a benefit. "Limited harvests actually help to get community support for the closure."
For the village, closing the reef means they have a source of good food whenever they need a feast for some ceremonial purpose, such as patching up relations with a neighboring clan or, as in this case, to celebrate the opening of a house for young, unmarried men to live in after they leave home. "It was awesome. Great dancing, so much fun," Cinner says. "Everyone was in these incredible costumes and these beautiful colors. It really blew my mind."
Cinner turned the data from that year into a Ph.D., which he completed in 2005 at JCU. After a year away -- part of it spent doing research with the Wildlife Conservation Society in Kenya and Madagascar -- he is now back at JCU, where the Australian Research Council funds a center for coral reef studies . He's trying to move his way up a ladder of research fellowships. His current job is the equivalent of an associate professorship in the United States, with pay equivalent to that of a senior lecturer in Australia. Australia doesn't have a tenure system, but Cinner's career track could eventually lead to a steady stream of research fellowships. And it's a great place to do science. "The intellectual environment where I'm working, I think it's unparalleled," he says.
Since finishing his Ph.D., Cinner has been working with McClanahan, studying how climate change affects coral reefs and the people who live with them. They've studied how coral bleaching caused by the 1998 El Niño affected communities in the western Indian Ocean. Coral bleaching is a response to stressors, such as higher temperatures. When coral polyps, which are translucent, get upset, they expel the tiny algae that live in their tissues and give coral its color. With the symbionts gone, the hard, white structure below -- calcium carbonate deposited by the polyps -- shows through. Sometimes the coral bounces back within weeks; sometimes it dies and comes back; and sometimes the reef falls apart. As Earth's oceans warm, bleaching is expected to increase in frequency.
Cinner and McClanahan have found that different places felt different effects of coral bleaching based on how much people depended on fish and tourism for a living and how flexible the local people were. In Madagascar, rigid taboos govern when people can fish and what gear they can use. "This actually leads to a bit of rigidity and stifles how people are able to adapt," Cinner says. In Kenya, some people are so desperately poor that when the reefs are in trouble, they just fish harder in the same places. But in the wealthier Seychelles, people have boats that can take them farther out, to target fish that don't live on the reefs.
These observations have led to ideas about how to protect reefs, and the people who depend on them, during coral-bleaching events. For example, if coral die and algae take over, it's much harder for coral to get reestablished. But if the reef hosts plenty of parrotfish -- which graze on algae and keep the reef clean -- the coral will be more likely to come back. Spearfishing particularly targets parrotfish, so one strategy might be to buy back spearfishing gear from Kenyan fishermen to protect parrotfish and make a reef more resilient to climate change, while leaving fishermen with other means to fish.
Cinner wants to extend this work to Indonesia and Papua New Guinea, looking for other ways to help people and coral reefs survive climate change. Working in so many cultures is challenging, he says. "I sometimes have to go through four different languages to remember the word. I might say it in Swahili, Portuguese, and Spanish, and then realize I'm trying to speak Malagasy or something." He says it's also tough being away from home so much of the time; last year, he was outside of Australia for about 150 days. But all that is outweighed by the excitement of his research. "You never know what's going to happen when you step off a bus into a dusty place you've never been," Cinner says. "That feeling never really goes away no matter how many times you do it. It's almost always worked out for me."
Photo (top): Joshua Cinner interviews an elder in the Tigak Islands near Kavieng, Papua New Guinea, in 2002
Helen Fields  is a science writer in Washington, D.C.