• Researchers have developed an Ocean Equity Index that seeks to measure how equitable ocean initiatives are based on 12 criteria.
• The index, which was introduced alongside an academic study, can be used by governments, companies and community or Indigenous groups; the authors hope its use will be institutionalized globally.
• Assessing equity quantitatively is challenging because of the subject’s complexity and because perspectives of equity vary widely across actor groups, experts say.

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Ocean projects and governance systems abound globally— everything from offshore energy to coastal aquaculture and fishing treaties — yet there is no standardized way to measure how equitable they are. Now researchers have developed an Ocean Equity Index that seeks to address that gap.

The index, released alongside a study in the journal Nature on Jan. 28, is designed to measure the equity of ocean initiatives based on 12 criteria and can be used by governments, companies and community or Indigenous groups.

“Inequality is on the rise,” Jessica Blythe, an associate professor of environmental sustainability at Brock University in Canada and lead author of the study, said in a video accompanying the index’s release. “A handful of corporations are generating billions in profit while marginalized [communities] are excluded from management decisions that affect them.”

The study was authored by 27 researchers from institutions around the world. They write that the index aims to help marine ecosystems and coastal communities achieve “better outcomes” when it comes to ocean initiatives.

“Once we start tracking equity, we’re going to see big changes,” Blythe said.

The “conceptual framework” of the Ocean Equity Index. The researchers who developed the index focused on three core types of equity: recognitional, procedural and distributional. For each type, they named two principles, and for each principle, two criteria, resulting in the 12 criteria that are scored in the index and which can be seen in the circle’s outer layer. Image courtesy of Blythe et al. (2026).

Economic activity in the ocean has increased significantly in recent decades, as have discussions of equity and justice in ocean fora. The language of equity was incorporated into the global biodiversity framework (GBF), signed in 2022, and the agreement on the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction that was reached the following year.

Yet translating such commitments into outcomes that are actually equitable isn’t easy, experts say. One notable tool for measuring equity has been the site-level assessment of governance and equity (SAGE), but that is specifically for conservation projects, terrestrial or marine, and requires a long, resource-intensive process. (Phil Franks of the International Institute for the Environment and Development, a U.K.-based research institute, developed SAGE and is also a co-author on the new Ocean Equity Index study.)

The Ocean Equity Index emerged from three years of work by the Blue Justice working group run by the Foundation for Research on Biodiversity, a France-based scientific foundation. Those involved initially thought of 150 criteria to measure equity but opted to keep the tool simple for usability, eventually settling on 12.

“As we were developing the tool, we were working with different groups around the world, and we kept hearing, ‘please, we can’t handle a tool that requires two weeks of training and six weeks in the field,’” Blythe told Mongabay.

The criteria include “human and Indigenous rights,” “inclusion and influence,” “transparency” and “assessment of harms.” The index is downloadable as a spreadsheet, and a user can grade an initiative on each of the 12 criteria, producing an overall score.

To test the index, the authors of the Nature study had it used it to assess six initiatives ranging from a local Tanzanian fish-drying project to a multinational, intergovernmental ocean conference declaration. The average score of the six case studies was 68%, out of a maximum possible score of 100%, with the lowest-scoring project at 44%.

Results from case studies. The Ocean Equity Index was used to assess six ocean initiatives. For each of 12 criteria, an initiative received a score that’s reflected in how much of that wedge is filled up. The assessors varied from initiative to initiative; in most cases their names are publicly listed on the index’s website. Image courtesy of Blythe et al. (2026).

Blythe said efforts at equity were being “dismantled in places like the United States,” but this tool was meant for groups that are interested in achieving equity. Many companies have expressed interest in the index, which is ideally used right from the planning phases of an initiative, she said.

Blythe said “the dream” would be for the index to be institutionalized at the global level — for example, into the GBF’s “30×30” target, which calls for 30% of land and sea to be protected by 2030 through “equitably governed systems of protected areas and other effective area-based conservation measures.” She said the index is meant to be flexible enough that it can be used to assess international treaties as well.

However, not all agree on the usefulness of the index. Peter Jones, emeritus professor of environmental governance at University College London in the U.K. who’s led in-depth qualitative research on equity in marine protected areas, expressed reservations, telling Mongabay in an email that the subject of equity was “subjective, multidimensional and complex” and didn’t lend itself to scored assessments. He also said that perspectives of equity vary widely between stakeholders — for example, a new marine protected area could be viewed differently by an Indigenous community than by an international NGO — and assessing equity based on one set of perspectives might lack democratic legitimacy.

Blythe said that equity is often overlooked because it’s so complex, and the index seeks to address that; she added that it should be supplemented with in-depth qualitative analysis when feasible. She also said the index could facilitate the “exploration of diverse perspectives” — different groups can fill out the index for the same project.

Blythe said the index could even be a “tool of resistance” used by marginalized groups to assess, for example, an offshore oil and gas operation in their area. She said the scores themselves are not as important as the dialogue they generate.

“The whole goal is to improve practices in the water,” she said.

Banner image: A shoal of batfish in Raja Ampat, Indonesia. Image by Noemi Merz / Ocean Image Bank.

 

Citations:

Blythe, J. L., Claudet, J., Gill, D., Ban, N. C., Epstein, G., Gurney, G. G., … & Zafra-Calvo, N. (2026). The Ocean Equity Index. Nature, 1-6. doi:10.1038/s41586-025-09976-y

Jouffray, J., Blasiak, R., Norström, A. V., Österblom, H., & Nyström, M. (2020). The blue acceleration: The trajectory of human expansion into the ocean. One Earth, 2(1), 43-54. doi:10.1016/j.oneear.2019.12.016

Jones, P. J., Stafford, R., Hesse, I., & Khuu, D. T. (2024). Incentive diversity is key to the more effective and equitable governance of marine protected areas. Frontiers in Marine Science, 11. doi:10.3389/fmars.2024.1412654

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