In 2012 the Ocean Health Index project – comprising dozens of marine scientists from around the world – created a system to distill the overall ocean health indicators for every coastal nation to a single number, from 0 to 100 ( The nations with high numbers have relatively healthy oceans; the nations with low numbers have unhealthy ones. Aimed at spurring improvements to ocean governance and health, the Ocean Health Index (OHI) establishes reference points for sustainable use of the ocean in 10 areas representing the range of benefits that a healthy ocean can provide (e.g., food provision, carbon storage, biodiversity, coastal livelihoods and economies).

Published last year, OHI scores by country and territory ranged from a high of 86 (Jarvis Island, a US territory) to a low of 36 (Sierra Leone). Global OHI scores have just been updated – the second annual assessment – and will launch on 15 October. As of that day, the full list of updated scores will be available at

The Ocean Health Index collaborative will release its first regional indices in the coming months – for Brazil, Fiji, and the US West Coast. These regional indices use local data for more precise assessments. The collaborative will also release a toolbox to make the computational framework for the Index available to scientists and policy-makers around the world – allowing institutions to create their own local and regional indices.

Ben Halpern from the University of California at Santa Barbara's National Center for Ecological Synthesis and Analysis is the lead scientist for OHI. We spoke with him about applying the Index at the local and regional level.

MEAM: Can you give some examples of how the regional indices could be used in policy-making?

Halpern: Several countries have efforts underway to develop their own national Index with sub-national scores, with the intent to use the results to help guide decisions about how to alter ocean management in those regions. The UN's World Ocean Assessment will be using the Index in its assessments. We are also exploring collaborations with several of the regional planning processes in the US, which are emerging as part of the US National Ocean Policy, to develop and use the Index to inform regional planning and decision-making.

We see a lot of potential for agencies, organizations, corporations, and even individuals to use the Index to raise awareness about the multi-dimensional nature of ocean health, how all the pieces fit together, and how their actions (or inaction) can affect overall ocean health beyond the direct impact of those actions. With guidance from policy and decision-makers about realistic management options, the new Toolbox will allow a wide variety of users to explore the potential outcomes of different management scenarios.

MEAM: Did you encounter any challenges in creating these regional indices?

Halpern: The number one challenge for calculating the Index, at any scale, is data gaps. Even on the US West Coast, which is one of the best studied and measured regions on the planet, we encountered many data gaps. But the Index is flexible on these data challenges. It allows use of best available proxy measures and can adapt how goals are measured based on the data and knowledge that exist in a region.

For more information:

Ben Halpern, National Center for Ecological Synthesis and Analysis, Santa Barbara, US. E-mail: