Analysing recently published satellite data, scientists have warned that if this trend of ocean greening towards the poles continues, marine food webs could be affected with potential repercussions for global fisheries. It’s a shift that stands to alter entire marine ecosystems.
Ocean waters are getting greener at the poles and bluer towards the equator, reflecting what scientists have suggested is a shift in concentrations of chlorophyll produced by phytoplankton – the microscopic marine organisms upon which the entire marine ecosystem food web is based.
Analysing recently published satellite data, scientists have warned that if this trend continues, marine food webs could be affected with potential repercussions for global fisheries. It’s a shift that stands to alter the entire marine ecosystem.
“In the ocean, what we see based on satellite measurements is that the tropics and the subtropics are generally losing chlorophyll, whereas the polar regions – the high latitude regions – are greening,” said Haipeng Zhao, a postdoctoral researcher and lead author on the study.
The study – conducted by Nicolas Cassar, the Lee Hill Snowdon bass Chair at Duke University’s Nicholas School of the Environment, and Susan Lozier, dean of the College of Sciences and Betsy Middleton and John Sutherland Chair at Georgia Tech – analysed satellite data collected between 2003 and 2022. It focuses on the open ocean and excludes data from coastal waters.
“If carbon sinks deeper or in places where water doesn’t resurface for a long time, it stays stored for much longer. In contrast, shallow carbon can return to the atmosphere more quickly, reducing the effect of phytoplankton on carbon storage,” said Cassar.
“Phytoplankton are at the base of the marine food chain. If they are reduced, then the upper levels of the food chain could also be impacted, which could mean a potential redistribution of fisheries,” said Cassar.
Read full article at Oceanographic Magazine
June 23, 2025