Planet’s darkening oceans pose threat to marine life, scientists say
Guardian4 days
Study: 21% of Global Ocean Has Become Darker
Above: UNDP Turkey 'Defender of Life in Water' World Free Diving record holder Sahika Ercumen in Balikesir, Turkey on May 24, 2025. Image copyright: Sebnem Coskun/Contributor/Anadolu via Getty Images
The Spin
Climate-concerned narrative
Ocean darkening represents one of the largest habitat losses on the planet, fundamentally altering marine ecosystems and posing a significant threat to global food security. The compression of marine life into shallower waters will intensify competition for resources, disrupt vital food webs, and potentially lead to the collapse of fisheries. This environmental crisis demands immediate attention.
Climate-skeptic narrative
The observed changes may be part of natural multidecadal variability rather than a permanent shift, as 20 years of data is insufficient to rule out normal oceanic cycles. The fact that 10% of the oceans have become lighter suggests that complex, dynamic processes are at work rather than uniform degradation. Additionally, the impacts vary significantly by region, indicating that localized factors may be more influential than global trends.