By DYLAN WALSH
What has been billed as the “Dow Jones of ocean health” is six months from release, and Ben Halpern is feeling the pressure. “We’re frantically wrapping up analyses,” Dr. Halpern, a research biologist at the University of California at Santa Barbara, said in a telephone interview.
Just as traders use various stock indices to monitor the global economy, micro-analyzing each blip, a team of nearly 50 scientists from many disciplines is designing an analogous tool to track the health of the world’s oceans and the implications for human well-being. (Dr. Halpern is part of a core team of 15 scientists who work on the index daily.)
The Ocean Health Index, a collaborative project of the group Conservation International, the National Geographic Society, the New England Aquarium, the National Center for Ecological Analysis and the Synthesis and the Sea Around Us project, measures, country by country, the ability of marine ecosystems to thrive and to support human livelihoods — goals that are often in tension. The index aggregates complex data into a single numerical score for every country.
With a maximum possible score of 100, the number measures how well a country fares in achieving optimal oceanic conditions and management practices; the lower the score, the worse conditions are.

“It’s easy to get lost in the hierarchy,” Dr. Halpern said of the final scores. The index actually nests measurement within measurement: each country’s score is based on 10 broad goals of ocean health like water cleanliness and biodiversity, and each of those goals relies on a more specific set of metrics.
Water cleanliness is, for example, subdivided into pathogens, chemical pollution, nutrient pollution, toxic contamination, trash and so forth. Metrics that are deemed more important carry greater weight. Along a beach heavily trafficked by tourists, for example, pathogens may carry greater weight than they do in Acadia National Park, where the aesthetic disruption from litter might be more problematic.
Over all, about 100 metrics are used to compile the index, which the team hopes to update at least once a year. Updating the scores will give policymakers an overview of ocean health trends over time and allow them to map out coordinated remedial efforts and conservation policies.
This ranking structure, both expansive and infinitesimal, has never before been applied to the oceans on a global scale. The index is also unique in its attention to the link between oceans and people, Dr. Halpern, said, noting that past examinations of marine health have tended to focus on pristineness as if the ocean were an untouchable wilderness.
“But the reality is we all like what the ocean provides — food to eat, a beach for recreating,” he said. “If these use values are not incorporated into conservation, then any solution will be doomed from the start. Solutions have to revolve around how people benefit.”
Data for the index are drawn from national databases and cover the exclusive economic zone of each coastal country — the marine territory extending 200 miles from shore over which nations maintain sovereignty. Yet the index offers the potential for a profusion of case studies on varying scales, from the health of the Long Island Sound or San Francisco Bay to large-scale analyses of the Mediterranean Sea or the vast open waters of the Pacific.
Stephen Katona, a former president of the College of the Atlantic, oversees the index, which combines two projects once independently assessing global ocean health and was seeded through contributions from several individual and corporate donors.
Thirty months later, challenges remain. A precise definition of ‘health,’ for example, appears elusive. “A booming whale-watching industry may come at the expense of thriving fisheries, while an emphasis on unpolluted waters may constrain coastal economies, three leading scientists contributing to the index noted in a recent article. “It is no trivial task to answer the question: healthy to whom?”
What is more, the data can be inconsistent in quality and quantity. The seas are vast and poorly explored, with many sections of ocean floor mapped less finely than the surface of Mars. “When you work at the global scale especially, and in the ocean particularly, there is always the issue of missing data,” Dr. Halpern said.
Yet identifying the critical gaps in local and global ocean data yields benefits for researchers, allowing them to optimize their time and resources in the future.
Efficient problem-solving seems critical at this point, given that many scientists believe that humans are currently at risk of causing a global mass marine extinction event — the sixth to take place in 600 million years.
“We hope the index will stimulate more concerted and sustained actions” on ocean issues, Dr. Katona said. “We’re trying to take an optimistic view — if we apply enough time, money and political will to these problems, we can bring them under control. We can mitigate them, probably even solve them.”
(Source: www.green.blogs.nytimes.com )