Ocean color may be changing due to climate change, according to a study

A research suggests that during the last two decades, climate change has drastically altered the color of the Earth’s seas. Though imperceptible to the human sight, these color changes have affected 56% of the world’s seas, a region greater than all of Earth’s land, according to the researchers.

Researchers from the National Oceanography Center in the UK, Massachusetts Institute of Technology (MIT), and other institutions discovered that tropical ocean zones close to the equator have in particular gotten consistently greener over time.

Since the color of the ocean is a direct reflection of the animals and elements in its waters, the researchers claim that the change in ocean color suggests that ecosystems inside the surface ocean must also be changing.

The researchers noted that while it is unclear precisely how marine ecosystems are altering to reflect the shifting color, human-induced climate change is probably the cause.

According to study co-author Stephanie Dutkiewicz, a senior research scientist at MIT, “I have been running simulations that have been telling me for years that these changes in ocean color are going to happen.”

“Seeing it happen in real life is disturbing but not shocking. And these alterations are compatible with climatic changes brought on by humans, according to Dutkiewicz.

Whatever is in the ocean’s top layers has an aesthetic effect on the color of the water. Deep blue seas often reflect relatively little life, whereas brighter waters typically represent ecosystems, including phytoplankton, which are plentiful in the upper ocean and contain the chlorophyll pigment.

The Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Aqua satellite, which has been monitoring ocean color for 21 years, was used by the researchers to analyze observations of ocean color. Seven visible wavelengths, including the two colors commonly used by academics to calculate chlorophyll, are measured by MODIS.

The seven ocean colors that the satellite detected between 2002 and 2022 were combined for the statistical analysis conducted by the researchers.

They started by examining how much the seven colors varied from place to region over the course of a year to get a sense of their inherent variances.

In order to examine how these yearly fluctuations in ocean color altered over a longer period of two decades, the researchers then enlarged their view. This research revealed a distinct pattern that was higher than the typical year-to-year fluctuation.