Researchers from the Monterey Bay Aquarium Research Institute (MBARI) in California examined two icebergs in the Weddell Sea, concluding that the ‘islands’ attract a mini-ecosystem of seabirds above sea-level and algae, krill and fish below.

The algae absorb CO2 from the atmosphere for photosynthesis, and some of this is then sequestered by the ocean.

“While the melting of Antarctic ice shelves is contributing to rising sea levels and other climate change dynamics in complex ways, this additional role of removing carbon from the atmosphere may have implications for global climate models that need to be further studied,” said Ken Smith, one of the MBARI researchers.

The number of Southern Ocean icebergs has increased in the last ten years as a consequence of global warming shrinking and splitting the area’s ice shelves.

But while the researchers could not verify the impact of their findings on the efficiency of the Southern Ocean carbon sink, which absorbs man-made CO2, they estimate that icebergs may increase the biological productivity of the Weddell Sea by close to 40%.