Lounging on Craig Venter's yacht in the South Pacific a couple of years ago, Neil Davies contemplated the tiny island of Moorea. Venter, famous for his work on the human genome, was sailing around the world to catalogue the microscopic life of the oceans. But Davies was pondering a more audacious goal: a plan to sequence an entire island. He mentioned the plan to a scientist on Venter's crew: “He just laughed,” Davies remembers.

Barcoding is great, and a lot of people are excited about it, but we intend to answer broader questions.

But Davies was on to something. He and a band of ecologists are launching the Moorea Biocode Project, which aims to turn the island into something like a model organism for tropical ecology. Christopher Meyer, a sea-snail expert at the University of Florida, Gainesville, is the plan's coordinator. Meyer says it will build on the ideas and technologies behind the scientific movement known as DNA barcoding, which classifies species according to a specific stretch of their genetic sequence. But Meyer says the Moorea project will go further.

He and his colleagues plan to collect multiple genetic and ecological data about each species on Moorea, which lies 15 km northwest of Tahiti. They will deposit the information in linked databases. Meyer hopes this will give scientists more information than barcoding a single DNA sequence. “Barcoding is great, and a lot of people are excited about it, but it can only answer questions about one narrow space,” Meyer says. “We intend to fill our data set with additional information so that we can answer a broader set of questions.”

The Biocode team will meet next month to begin designing databases. Meanwhile, entomologist Rosie Gillespie — based, like Davies, at the University of California, Berkeley — will begin collecting insects on Moorea and sequencing their DNA. Then, in March, French icthyologist Serge Planes of Perpignan University will start sampling fish from Moorea's reefs; he hopes to collect 80% of the 600 fish species in four-and-a-half weeks. Researchers intend to start using these data immediately to look at topics from invasive species to biodiversity.

Nancy Knowlton, a coral-reef expert not involved with the Biocode project, says such data could resolve many unanswered questions. For instance, she says, it is often hard to identify tropical reef fishes, many of which have been described only in small journals. Having a DNA code linked to a visual key could help biologists to make quicker, more accurate identifications. And that could help them to understand crucial parts of reef ecosystems, such as how many species live on them and how well they are doing.

Pacific crews: collecting genetic data from all life on Moorea should shed light on biodiversity. Credit: Y. ARTHUS-BERTRAND/CORBIS

“Our estimate of the number of species on reefs rests on incredibly shaky ground,” says Knowlton, who directs the Center for Marine Biodiversity and Conservation at Scripps Institution of Oceanography in La Jolla, California. “These molecular tools have the potential to help us fine-tune those estimates to get a total sense of diversity, and what we're losing as the reefs degrade.”

The Biocode scientists also want to learn about the general properties of ecosystems. Moorea is less diverse than other islands farther east, so it may serve as a reference site that can be compared with more complex systems in Australia, Papua New Guinea and southeast Asia. “It's like comparing the processes of Caenorhabditis elegans with humans; that's a very powerful approach,” says Davies.

Moorea is a logical choice for a model system of ecology, experts say, because it has been well studied by researchers at two field stations there for decades. The project can also tap into other, similar efforts that are already under way, such as the Census of Marine Life, in which Knowlton is involved.

Putting a whole island under the microscope won't be easy. But the Biocode scientists say they are building on a tide of change that is revolutionizing taxonomy and ecology. “We have technological challenges; we have sampling challenges,” Meyer admits. “But the idea of barcoding has really hit a tipping point. This is the perfect time to try something like this.”