The clean water index measures pollution by chemicals, excessive nutrients, human pathogens and trash in estuarine, coastal, and open ocean waters. Clean waters target is 70 out of 100. The reference point is that there should be zero pollution from chemicals, nutrient, human pathogens and trash. This goal score is higher when the pollution of estuarine, coastal, and open ocean waters is minimized. The goal score is lower when there are high levels of pollutants.
Citation formats
Highest clean water scores worldwide 2025, by select country
The country with the highest clean water score worldwide in 2025 was the Seychelles. With a score of ***** out of 100, this was more than ** points higher than the goal of ** points. Australia and Greenland followed, with scores of ** and **** points, respectively. The clean water index measures the degree to which ocean regions are free of contaminants such as chemicals, eutrophication, harmful algal blooms, disease pathogens, and trash.
Profit from the additional features of your individual account
Currently, you are using a shared account. To use individual functions (e.g., mark statistics as favourites, set
statistic alerts) please log in with your personal account.
If you are an admin, please authenticate by logging in again.
Learn more about how Statista can support your business.
Ocean Health Index. (July 8, 2026). Leading scores of clean estuarine, coastal, and open ocean waters worldwide as of 2025, by selected country [Graph]. In Statista. Retrieved September 01, 2026, from https://www.statista.com/statistics/1143413/clean-water-index-region-globally/
Ocean Health Index. "Leading scores of clean estuarine, coastal, and open ocean waters worldwide as of 2025, by selected country." Chart. July 8, 2026. Statista. Accessed September 01, 2026. https://www.statista.com/statistics/1143413/clean-water-index-region-globally/
Ocean Health Index. (2026). Leading scores of clean estuarine, coastal, and open ocean waters worldwide as of 2025, by selected country. Statista. Statista Inc.. Accessed: September 01, 2026. https://www.statista.com/statistics/1143413/clean-water-index-region-globally/
Ocean Health Index. "Leading Scores of Clean Estuarine, Coastal, and Open Ocean Waters Worldwide as of 2025, by Selected Country." Statista, Statista Inc., 8 Jul 2026, https://www.statista.com/statistics/1143413/clean-water-index-region-globally/
Ocean Health Index, Leading scores of clean estuarine, coastal, and open ocean waters worldwide as of 2025, by selected country Statista, https://www.statista.com/statistics/1143413/clean-water-index-region-globally/ (last visited September 01, 2026)
Leading scores of clean estuarine, coastal, and open ocean waters worldwide as of 2025, by selected country [Graph], Ocean Health Index, July 8, 2026. [Online]. Available: https://www.statista.com/statistics/1143413/clean-water-index-region-globally/
