Planet’s darkening oceans pose threat to marine life, scientists say

Changes in global photic zones between 2003 and 2022 are shown with red areas to indicate ocean darkening and blue lightening. Illustration: Thomas Davies/University of Plymouth

Great swathes of the planet’s oceans have become darker in the past two decades, according to researchers who fear the trend will have a severe impact on marine life around the world.

Satellite data and numerical modelling revealed that more than a fifth of the global ocean darkened between 2003 and 2022, reducing the band of water that life reliant on sunlight and moonlight can thrive in.