MIT researchers say climate change will intensify ocean colors

Changes in hue will identify signs of wide-scale changes to marine ecosystems

Researchers at Massachusetts Institute of Technology have detected climate change impacts on phytoplankton in the world’s oceans that they say will intensify blue and green regions of ocean color over the coming decades.

Satellites should detect these changes in hue, providing early warning signs of wide-scale changes to marine ecosystems, MIT researchers reported in an article in Nature Communications, an open access journal that publishes high-quality research from all areas of the natural sciences.

The researchers said they have developed a global model that simulates the growth and interaction of different species of phytoplankton, or algae, and how the mix of species in various locations will change as temperatures rise around the world.

The research team also simulated the way phytoplankton absorb and reflect light, and how the ocean’s color changes as global warming affects the makeup of phytoplankton communities.

They ran the model through the end of the 21st century and found that by the year 2100 more than 50 percent of the world’s oceans will shift in color, due to climate change.

They concluded that blue regions, such as the subtropics, will become even more blue, reflecting even less phytoplankton, and life in general, in those waters, compared with today. Some regions that are greener today, such as regions near the poles, may turn even deeper green, as warmer temperatures brew up larger blooms of more diverse phytoplankton.

While the model suggests the changes won’t appear huge to the naked eye, and the ocean will still look like it has blue regions in the subtropics and greener regions near the equator and poles, it will be different enough that it will affect the rest or the food web that phytoplankton supports, said lead author Stephanie Dutkiewicz.