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Is the Global Ocean Healthy? We Can Answer That Now

As the Ocean Health Index makes its public debut, three of its parents describe the moment of 'Eureka!' in summing up the well-being of the global ocean and its human dependents.

There are very few moments in science where years of work by dozens of people produces a single outcome, at a single moment in time. The "Eureka!" event for the Ocean Health Index project—which makes its public debut today in the journal Nature—occurred last spring when a global score emerged from a thicket of data.

More than a year ago we started writing a series in this magazine about the process of developing the Ocean Health Index, hoping to offer a window into the challenges of a complex research project that tackles big, pressing questions. In this case, we are trying to capture the idea that people are part of the ocean, so that measuring ocean health requires one to consider and combine both human and ecological concerns.

More than three dozen scientists representing disciplines as diverse as ecology, oceanography and economics were literally in the trenches then, solving known problems and discovering unexpected ones. Known questions included things like ‘How do we best quantify the condition of wild-caught fisheries by building on decades of science and at the same time contextualize it against the condition of newly important ocean benefits such as carbon storage?’ Unexpected hurdles came from things like trying to measure sustainable coastal tourism globally when few data exist—a surprise to us, since tourism is such an important industry worldwide. Though the goal of our effort is as much to identify data gaps as it is to synthesize existing information, any light at the end of the tunnel seemed distant and dim.

Several months ago that light shone brightly. We finally had pulled together all available data relevant to understanding how each of the components of the Ocean Health Index were faring, finalized our decisions about how to combine the data, error checked everything, and cranked through all the calculations. We were about to find out the score—the health of the world’s ocean represented as a single number between 1 and 100. After two years working on the project, the moment was as suspenseful as election night. Our result: 60.

The 10 components of the Ocean Health Index and the global score each received. (Click to enlarge.)


We quickly fired off an email to the other project scientists, slightly giddy as we shared the score.

The euphoria was short lived. Emails flooded back. What does the score mean? Is it good or bad? Is the ocean healthy or not? Now we had to make sense of the number we had been working so hard to discover.

About the Project!

Ocean health means different things to different people, and current assessments of ocean health focus predominantly on the state of the natural environment. The Ocean Health Index project was founded by Conservation International, The National Geographic Society, New England Aquarium, and the National Center for Ecological Analysis and Synthesis. The project aims to develop a set of indicators that describe ocean health according to how people benefit from and affect marine ecosystems. Here are the articles has published on the subject:


The Making of the Ocean Health Index

Ocean Index Navigates Between the Politic, the Pristine

Setting Targets in the Ocean Health Index

Three Reasons for Creating a Single Ocean Health Index

Ocean Health Index Accounts for Human Benefits

Ocean Health Index: The Audacity of Necessity

Our efforts to establish an Index score now means that we will have something to compare ocean health to next year, in five years, and in 20 years. We have a benchmark against which we can assess and document progress and, where necessary, point out and hopefully reverse declines. Our paper in Nature (and other papers explaining our process and results) will be our invitation to the world's scientific and policy community to use, improve and expand this new tool.

A score of 60 is far from perfect, with ample room for improvement. Humans could be managing our oceans much more effectively and sustainably, and get a lot more benefit from them in the process. But the score is more than half way to perfect, so positive things are happening too.

It is almost universally true that food provision and coastal tourism could be substantially improved; both scored below 25 out of 100. At the same time, in countries with scores below 50, it was often the case that biodiversity was in decent shape—marine extinctions, so far, are rare. This hodgepodge of factoids circles back to the idea that the composite score of 60 isn’t too bad, but it’s nothing to brag about either. It depends a lot on which parts of the Index you focus on, and where on the planet you are looking.

In short, we are optimistically pessimistic, or pessimistically optimistic. The score of 60 indicates that real and meaningful successes are present around the world that should be identified, celebrated, and supported. The score of 60 also highlights how much more stewardship of our ocean ecosystems is required for them to be fully sustainable and healthy.

While this single composite score for the health of the global ocean has tremendous potential for communication and raising awareness, it doesn’t tell the complex and nuanced story of how and why the score emerged. Distilling that story has been one of the major challenges, and accomplishments, of our group since 60 emerged as the number. How much do Index scores vary from place to place around the world? And, since the Index is estimated from 10 widely held public goals for ocean health, how do the individual goal scores vary?

Many more countries score low on the Index than score high. More than 30 percent of coastal countries received a score less than 50, while fewer than 5 percent scored higher than 70. Country scores range from 36 to 86, with Jarvis Island (an uninhabited island territory in the Pacific), Germany and the Seychelles in the top five, and Sierra Leone, Liberia and Ivory Coast (all in western Africa) producing the lowest scores. The United States scored 63, above average but with plenty of room for improvement.

As with election nights, once the rush from getting results wears off one starts looking forward again, thinking about what’s next. We are excited to see the Index applied in ways we expect, such as monitoring the health of the Puget Sound or of various National Marine Sanctuaries, as well as others yet to be identified. More than anything, though, we are excited about the role of the Index as a motivator for the collection of new data and new ways of thinking about and evaluating ocean policies and practices. Already, we have seen this Index advance science and policy discussions regarding the metaphor of ocean health by giving it at least one meaningful and concrete definition.

We are both hopeful and humble about the future of the oceans, and what the Index can do to help improve them. The Index is a bit like democracy in Winston Churchill’s famous quote: ‘It has been said that democracy is the worst kind of government except all the others that have been tried.’ There is plenty of room for improvement in the Index, but it will be an important tool for moving ocean health in the right direction. We look forward to being part of bringing that vision to fruition.

The views expressed herein are those of the authors and do not necessarily reflect those of the National Oceanic and Atmospheric Administration or its agencies.