October 16, 2000

ne little island in the South Pacific draws two million tourists each year. Few visitors to Bali miss the opportunity to don a mask and snorkel for an underwater show of brilliantly colored fish playing hide-and-seek in a tropical paradise. What they may not realize is that some of the reefs may be on the verge of becoming a paradise lost.

"We've found very few signs of new life among old reefs in one region of Bali," says James Kremer, a professor of marine sciences. "Although these reefs appear to have been built by healthy coral in the past, now most of the coral is dead."

For the past 14 years, Kremer has been working with Stephen Lansing, an anthropologist at the University of Arizona, who studies the Balinese traditional rice growing culture. You may wonder what rice paddies have to do with an environmental crisis 20 feet below water. The answer is fertilizer.

Kremer is a coastal systems ecologist who studies large scale interactions in ecosystems. And, as he likes to point out, his specialty is that he is a generalist. Instead of devoting all his efforts to one facet of the system, such as a group of organisms or a specific habitat, he uses information from many specialists to piece together the chain of events that leads to dramatic ecological transformations within coastal waters.

Bali's coral reefs are undergoing just such a transformation, and the chain of events begins with rice, the island's number one export. The scientists have focused several studies on rice production. During an early project, Lansing and Kremer started looking at the possible ecological implications of the traditional religious system, which oversaw rice production by coordinating the activities of farmers throughout the watershed.

"We showed that religious tradition had optimized two conflicting management goals, fair water allocation and pesticide control," Kremer says. "And then in walks the Indonesian government with different rice and planting strategies and requires that farmers use fertilizer with high levels of the nutrients phosphorus and potassium. This was the green revolution."

The government's goal was to increase crop yields and for the next four years it worked. But then yields started to crash. Kremer believes one reason for the failure was the weakening of the traditional religious system of cooperation.

Their research findings led to changes. Instead of government mandates about the use of water and pesticides, farmers' cooperatives once again regulate their use.

The team's most recent study uncovering coral reef damage is expected to lead to other changes. The Indonesian government is being urged to review its agriculture policy after initial findings indicated high levels of phosphorus and potassium in the water where the reefs are in the worst shape.

"No one had ever looked at how much fertilizer ended up in the water," Kremer explains. "The government requires the application of more fertilizer than the rice paddies need. So what is not utilized by the plant washes out to the ocean."

The nutrients arrive in coastal waters and transform these habitats. The excessive levels can set off toxic algal blooms that kill large numbers of fish and make shellfish poisonous to consume. They can trigger the spread of the Crown of Thorn starfish, which eat away at the coral. The list could go on and on.

The team's next related project is just getting under way. It is funded through a three-year grant for $1 million from the National Science Foundation. Because water and farming connect the Balinese people from the mountain tops to the ocean, the scientists are looking at kinship among farmers from village to village. Cooperation is so important that kinship relationships may have emerged that have improved their effectiveness in dealing with conflict and pressures from changing weather and crops. DNA samples from the farmers will pinpoint maternal and paternal lineages.

Meanwhile, Kremer is wrapping up work on a three-year research proj-ect. He is creating a computer model that anticipates how the nutrients, nitrogen and phosphorus, impact coastal waters. He calls the program CLUE - for Changing Land Use and Estuaries and because he hopes the model will give people a clue about the impact development has on nearby bodies of water.

"Nutrient loading associated with human development has arguably the most pervasive impact on coastal waters nationwide," he says.

Kremer's students - three undergraduates and two graduates - have been gathering field data for the program from 12 sites in Connecticut, Rhode Island and Massachusetts. The computer program will be available through a password-protected website to local authorities who make decisions that affect land use.

Janice Palmer