Seas will change colour as climate heats up


She says that current methods for monitoring phytoplankton provide information about local or regional changes but this new method, which uses satellite data, may offer a clearer, better picture of ocean change.

The study said the blue regions, such as the subtropics, will turn shades darker, reflecting even less phytoplankton - and life in general - in those waters.

Researchers say the colour changes are down to the effect of climate change on populations of tiny water-dwelling organisms, known as phytoplankton, that convert sunlight into chemical energy through photosynthesis, as well as effects on levels of other colourful components of the oceans. Their model can estimate wavelengths of light that are absorbed and reflected by the ocean, which obviously changes by a given region and the organisms in the water.

The study found that because climate change is affecting the oceans ecosystems, this could alter the colour of the water as early as the end of the twenty-first century.

"The change is not a good thing, since it will definitely impact the rest of the food web", said study co-author Stephanie Dutkiewicz, a principal research scientist in MIT's Department of Earth, Atmospheric, and Planetary Sciences.

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Climate change might be changing the oceans' color in the future, new research reveals. By contrast, barren regions of open ocean appear as deep blue from space.

Researchers from MIT developed a model to simulate the growth and interaction of different types of phytoplankton and algae, observing how changing temperatures of the ocean over the coming decades will influence the mixing of those species. When sunlight hits the ocean, water molecules absorb most of the light, except for the blue part of the spectrum, which is reflected back. Phytoplankton can absorb blue, but less green. By the year 2100, they report, over 50% of the world's oceans will suffer shifts in color due to climate change.

At the heart of the phenomenon lie tiny marine microorganisms called phytoplankton, which are crucial to ocean food webs and to the global cycling of carbon - and sensitive to the temperature of ocean waters.

A United Nations-backed panel of scientists said previous year that it will require "unprecedented" action over the coming decade for the world to limit warming and stave off the most catastrophic consequences of climate change.

"Chlorophyll is changing, but you can't really see it because of its incredible natural variability", Dutkiewicz says.

Since the late 1990s, satellites have taken continuous measurements of the ocean's colour. "But you can see a significant, climate-related shift in some of these wavebands, in the signal being sent out to the satellites".

"We're going to be able to see - not by eye but by instrument - that the colour of the ocean is changed". As such, life in these areas as we know it today is likely to also change.

"It could be potentially quite serious", Dutkiewicz added of the change in color in the oceans. Thus, the climate change would bring a major change in quantity of phytoplankton in the ocean, as a result, support provided by this element to different types of food chains will get affected.

"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", said Dutkiewicz.