Introducing the Ocean Health Index

KELLY SLIVKA

August 15, 2012

Scores on the Ocean Health Index ranged from 36 (Sierra Leone, in West Africa) to 86 (Jarvis Island in the Pacific).

In a potential milestone for ocean management, a team of collaborators has produced the first Ocean Health Index, a tool for appraising the state of the world’s oceans. The index takes into account the major factors that influence the quality of regional marine ecosystems like fisheries, biodiversity, tourism and carbon storage and then assigns a score from zero to 100 for each place.

Globally, the oceans received an ocean health score of 60. The lowest score was 36 (Sierra Leone’s waters) and the highest was 86 (waters surrounding uninhabited Jarvis Island, near Hawaii).

Dozens of scientists, policymakers and conservationists in the United States and Canada came together over the last two years to create the index, which is described in detail in a paper published online in the journal Nature. Their goal was to find a way to compare different parts of the ocean that are heavily used by humans and determine whether this activity is sustainable or in need of better management.

“You can’t manage something like ocean health without actually having a tool to measure it,” said Ben Halpern, director of the Center for Marine Assessment and Planning at the University of California, Santa Barbara and one of the leaders of the indexing project. He said the indices provide people who ply the oceans an idea of how their practices affect the marine resources they depend on.

For Dr. Halpern, who is accustomed to field research like surveying corals and counting fish while scuba diving, creating a model based on so many intangible social and economic factors was a challenge. “How do you come up with proxy numbers for things like social values?” he said. The researchers identified goals that varying cultures could relate to.

Mike Fogarty, who studies ecosystems for the National Oceanic and Atmospheric Administration’s Northeastern division, said the index provided a framework that would help federal, state and local agencies in the United States work in tandem on improving coastal health.

NOAA has been focusing its energies on a full ecosystems-based approach to ocean management since President Obama signed the National Ocean Policyinto law in 2010, and the index will complement the agency’s efforts, Dr. Fogarty said.

Most of the discrete marine regions measured by the project are in waters within 200 miles of a country’s shores, the “exclusive economic zones” within which each nation is acknowledged to have control over the resources.

A seaweed farmer in Kutuh, Indonesia.

The sustainability of ocean usage is a big part of the score for each region. Other broad factors taken into account by the index are the cleanliness of the water, coastal protection and the “sense of place.”

The index also allows individual countries to weight conservation values to reflect their beliefs on how the ocean should be best used. If a country thinks the best way to treat to the ocean is to preserve it, it can weight conservation factors more heavily in its score. If a country thinks the best use for the ocean is to extract resources from it, it can weight those factors more heavily.

Weighted for preservation, the global ocean score would be 67; weighted for high-resource extraction, the score would be 57.

Developing nations, which typically are less able to plan and control ocean usage, tended to have lower scores, and developed nations generally had higher scores. There were a few exceptions: the Seychelles and Suriname scored high, while Poland and Singapore scored relatively poorly.

United States waters received a score of 63; Britain, 61; India, 52; and China, 51.

It’s important not to equate Ocean Health Index scores with school grades, Dr. Halpern said. Although the world’s oceans received an overall score of 60, they don’t get an F for health. The score means there’s lots of room for improvement, “but 60 also means here must be some good things going on,” he said.

A 60 is right around the score he expected for the global oceans, he said. “I think if it had gotten a 90 or a 15, we would have been surprised,” Dr. Halpern added.

The project’s collaborators hope to fine-tune the factors built into the index further and reassess the world’s oceans over time while communicating with policymakers and ocean managers. Publishing the index is “just the launch pad for what will hopefully be the much larger and more substantial effort of engaging with people,” Dr. Halpern said.

Halpern et al./Nature 2012The ocean health score for an aggregate of all countries. The outer ring is the maximum possible score for each goal. The petal’s length represents the score for that goal, and its width indicates how the goal was weighted.