A major change in the color of the world's oceans has been found in a recent study headed by B. B. Cael from the UK's National Oceanography Centre. This discovery has important ramifications for marine ecosystems and the global carbon cycle. The study, which examined 20 years' worth of data from NASA's Aqua satellite, discovered that 56% of the world's sea surface had changed significantly in color since 2002, mostly becoming greener.

The greening trend is more noticeable in tropical and subtropical areas, suggesting that phytoplankton communities—microscopic creatures that are the base of the marine food web and are essential for sequestering carbon—may be changing. The MODIS (Moderate Resolution Imaging Spectroradiometer) instrument on board the Aqua satellite, which has been tracking ocean color for 20 years, provided data for the study. Through examination of the complete range of visible light reflected from the ocean's surface, scientists were able to identify alterations that could have been overlooked by conventional measures of chlorophyll. In particular, the study team discovered that tropical water areas close to the equator had gradually grown greener over time. Given that the color of the ocean is a direct reflection of the marine life and other elements it contains, the change in water color suggests that marine ecosystems must also be changing.


(Source: Google Images)

Climate Change Is The Inevitable Force Bringing Such Drastic Occurances ~ 

Cael emphasized that these color variations most likely indicate more significant alterations to ocean ecosystems, such as altered populations of zooplankton, more detrital particles, or distinct plankton assemblages. The study team excluded plastics and broad pollution as potential causes, pointing out that these are not common enough to explain the alterations they saw. Increased ocean stratification brought on by climate change is one important element that the study uncovered. Certain forms of plankton evolved to nutrient-poor habitats are favored by warming surface waters because they are less likely to mix with deeper, nutrient-rich layers. Although the discoveries were discovered far sooner than expected, they are consistent with projections made by climate models. This early confirmation of the trend emphasizes how quickly our oceans are changing due to climate change and how important it is to keep monitoring and researching these changes. Lead author B. B. Cael, PhD '19 of the National Oceanography Center in Southampton, United Kingdom, continues, "This gives additional evidence of how human activities are affecting life on Earth over a huge spatial extent." "That's just one more way that people are changing the biosphere."

“I’ve been running simulations that have been telling me for years that these changes in ocean color are going to happen,” says study co-author Stephanie Dutkiewicz, senior research scientist in MIT’s Department of Earth, Atmospheric and Planetary Sciences and the Center for Global Change Science, in a media release. “To see it happening for real is not surprising, but frightening. And these changes are consistent with man-induced changes to our climate.”

In the future, NASA's PACE satellite mission, scheduled for launch in fall 2024, is expected to deliver even more precise observations of ocean color, which could provide more information about the diversity and growth rates of phytoplankton. The enormous effects of climate change on Earth's most important ecosystems are visibly manifested in the changing colors of our oceans, as our understanding of these changes grows.