How Healthy Are Our Oceans?

A tiny patch of Pacific Ocean, located south of Hawaii, has been declared the world’s healthiest piece of ocean water, according to a new report by the University of California, Santa Barbara, and published in the science journal Nature.

The report is the work of 30 scientists, who developed a ranking system to assess the health of oceans around the world, measuring them for both potential for human use and ecosystem sustainability.

Jarvis Island, an uninhabited island that’s just 4.5 square kilometres in size and is a protected territory of the United States, is the site of the world’s healthiest ocean water, scoring 86 out of 100. The world average is 60.

The rating of least healthy went to the West African coastline. Out of its 11 ocean areas, 10 were ranked lowest in the world. Sierra Leone came in at the bottom spot, with a ranking of 36.

The index isn’t meant to measure the purity of the water; rather, its intended to assess the benefits the water can offer for that region. The index ranking is based on how well the coastal region scores on factors such as clean water, food provision, biodiversity, protection programs, recreation, economic support and “sense of place.”

It’s the first such assessment of the relationship between oceans and humans.

“The index helps us separate our gut feelings about good and bad from the measurement of what’s happening,” said Dr. Ben Halpern, a marine scientist from the U.S.National Center for Ecological Analysis and Synthesis, and one of the leaders of the survey.

“It provides a tool that puts meat on the metaphor of ocean health, which is bandied about all over the place but without anything to use to actually measure it.”

A map of overall Index scores for each coastal country. Credit: Ben Halpern, NCEAS

Because the index measures more than just water purity, developed regions are likely to score higher, since they’re likely to have stronger policies in place protecting and building upon their water. For example, countries that have heavy industry along their coast may still rank high if they have proper initiatives in place to protect the waters.

“To many it may seem uncomfortable to focus on benefits to people as the definition of a healthy ocean,” said Steve Katona, another of the study’s lead authors, who is with Conservation International.

“Yet, policy and management initiatives around the world are embracing exactly this philosophy. Whether we like it or not, people are key. If thoughtful, sustainable use of the oceans benefits human wellbeing, the oceans and their web of life will also benefit. The bottom line is ‘healthy ocean, healthy people, healthy planet.’”