Ocean Health Index

open-source tools and resources

for marine science and management

What is the OHI?

The Ocean Health Index ('OHI') is a way to measure how healthy oceans are. Understanding the state of our oceans is a first step towards ensuring they can continue providing humans benefits now and in the future.

Learn More Visit our sister website oceanhealthindex.org
OHI Flower plot

What is OHI+?

Independent assessments at any scale.

OHI+ assessments use the OHI framework and are independently-led by anyone interested. OHI+ assessments are often conducted at smaller spatial scales with the purpose of informing marine policy.

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Where have assessments been done?

Assessments at the global scale have been completed from 2012-2015. Assessments have also been completed or are underway at smaller scales within coastal countries or groups of countries around the world.

View all assessments View publications

How do I get started?

We provide free instruction and software so you can conduct your own OHI+ assessment. There are four phases to the assessment process: Learn, Plan, Conduct, and Inform.

Start your OHI+ assessment now


Five years of global Ocean Health Index scores

Today the Ocean Health Index (OHI) announces the completion of the fifth annual global Ocean Health Index (OHI) assessment at the 17th annual Global Environment Facility Large Marine Ecosystem meeting in Paris. Global OHI scores represent ocean health for 220 coastal nations and territories and are calculated with the same methods and best available information each year. The OHI, established in 2012, is a partnership led by scientists from the National Center for Ecological Synthesis and Analysis (NCEAS) at the University of California at Santa Barbara and Conservation International.

Older posts View all OHI Science news