Lakes worldwide are changing colour – possibly due to human impact

Published 18 March 2025

Satellite image of Lake Yamzho Yumco in the Tibet Autonomous Region of China – one of the lakes that, thanks to minimal human impact, has not undergone major colour changes. (Photo: Google Earth)

Over the last 40 years, the majority of the world’s lakes have changed colour, according to a new study. The research team analysed 32 million satellite observations from over 67,000 lakes. Major changes in the lake ecosystems are thought to be the cause.

Lakes are critical components of Earth’s ecosystem. They provide habitats for aquatic and terrestrial species, support biodiversity and help maintain ecological balance. Lakes are also crucial for providing drinking water, supporting agriculture and influencing climate through their effects on temperature, humidity and atmospheric processes.

The colour of lakes is an important indicator of how healthy they are. Different shades reveal the ecological state of lakes and the ongoing physical and biochemical processes.

In a new study published in the scientific journal Water Resources Research, a team of researchers analysed 32 million satellite images of over 67,000 lakes from 1984 onwards. Zheng Duan, Senior lecturer at Dept of Physical Geography and Ecosystem Science and a member of MERGE, are one of the researchers in the team.