Researchers at MIT have learned many of the world’s oceans are going to change colour as a result of climate change.
In the oceans, microscopic algae known as phytoplankton float through the water. Phytoplankton contains chlorophyll, a pigment which absorbs the Sun’s blue wavelengths and reflects green light to produce carbon for photosynthesis.
Colder waters with higher populations of phytoplankton tend to be greener, while tropical waters with less phytoplankton take on a more blue or turquoise hue.
Many people might choose their holiday destination based on the colour of the inviting, glittering turquoise water laying beyond the beach of a tropical island, but soon many of the colours are likely to change.
Researchers developed a model which simulates the growth and interaction of different species of phytoplankton, and predicts how the mix of species will change as temperatures rise around the world.
The results revealed that as warm, subtropical waters get warmer with climate change, populations of phytoplankton are projected to decrease, giving the water a bluer colour.
The colder, algae-rich green waters will also get warmer, potentially spurring the growth of more diverse phytoplankton. Some oceans are likely to get greener, but is likely others will also turn more blue.
Satellites should detect the differences, which will be early warnings of wide-scale changes to marine ecosystems.
Stephanie Dutkiewicz, the lead author behind the study, explained the findings in a statement.
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.
That basic pattern will still be there. But it’ll be enough different that it will affect the rest of the food web that phytoplankton supports.
There will be a noticeable difference in the colour of 50 percent of the ocean by the end of the 21st century.
It could be potentially quite serious. Different types of phytoplankton absorb light differently, and if climate change shifts one community of phytoplankton to another, that will also change the types of food webs they can support.
Speaking to IFL Science, Dutkiewicz added:
Only some regions that are greener now are likely to get even greener – many other greener regions are likely to get bluer. But in most places, there will be a shift between different species of phytoplankton.
It’s worrying how quickly and massively climate change is affecting our planet.
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