One of the best-known impacts of climate change is the loss of sea ice in the Arctic, but also in parts of the Antarctic: the poles are increasingly turning from white to blue. However, in the shallow seas near continental landmasses, the colour green also enters the picture: with the ocean ice-free for longer periods, the growing period for algal blooms also grows longer. These algae, in turn, provide food for seafloor-dwelling organisms, who use the carbon from their food to grow their bodies and shells.
One of the best-known impacts of climate change is the loss of sea ice in the Arctic, but also in parts of the Antarctic: the poles are increasingly turning from white to blue. However, in the shallow seas near continental landmasses, the colour green also enters the picture: with the ocean ice-free for longer periods, the growing period for algal blooms also grows longer. These algae, in turn, provide food for seafloor-dwelling organisms, who use the carbon from their food to grow their bodies and shells.
A new study by BAS marine ecologist Dr David Barnes, published in the journal Global Change Biology this month, aims to unpick the puzzle of how these seafloor communities – known as benthos – are responding to changes at the sea surface. Understanding these ecosystems is important as many organisms use carbon to build their shells, storing it away in seafloor sediments when they die and removing it from the global carbon cycle for millennia. This means that if the benthos thrives, it can play a bigger role in offsetting emissions of carbon dioxide into the atmosphere.
The ocean soaks up large amounts of carbon from the atmosphere, but its ability to absorb the increasing quantities produced by human emissions is limited. The role of polar seafloor communities in carbon storage processes is poorly studied, but it may turn out to be an important negative feedback mitigating climate change: as polar seas become ice-free for longer periods, algal blooms have a longer growing season. They therefore provide food for benthos communities throughout a larger part of the year, enabling them to store more carbon and preventing it from returning to the atmosphere.
Read more at British Antarctic Survey
Image: Diving operations under the sea ice near Rothera Research Station. (Credit: British Antarctic Survey)
