Researchers have found that the melting of icebergs isn’t all bad news, and they have more of a role to play in the ecosystem than just causing a rise in sea levels. It has been observed that as they melt they help remove large amounts of carbon dioxide from the atmosphere.

 

By following two free drifting icebergs and observing the surrounding water in the North West part of the Weddell Sea in the Southern Ocean they have shown an increase in activity extending to about 3.7 km from the iceberg.

 

The two icebergs, one of surface area 0.1 square kilometers, and the other of 30.8 square kilometers (as seen from above) were observed during the Antarctic spring (December) of 2005. As they melted they released large amounts of minerals that had been trapped in the ice. These nutrients in turn prompted a growth of phytoplankton. These organisms absorb carbon dioxide from the air and are then eaten by shrimp-like krill, which trap the carbon in their waste which sinks to the bottom of the ocean. Ultimately the melting of the icebergs leads to the long term removal of carbon from the atmosphere.

 

Over the last decade, as global warming has continued, the number of icebergs has increased. This is due to ice breaking off of the vast ice shelves in the Southern Ocean. This larger number of icebergs is what prompted scientists from the Monterey Bay Aquarium Research Institute in California to look into their affect on the environment. Their results were published earlier this month in the online science journal, Science Express. By observing the waters for 9 kilometers around the icebergs using a trawl net and a remotely operated vehicle (ROV) they were able to observe the increase in activity.

 

In a follow up to these findings they hope to perform a study on smaller icebergs which account for ninety percent of all of the ones found in the Southern Ocean.

 

Using satellite footage and by extrapolating to all of the icebergs found in the Southern Ocean it is thought that this affect is occurring over 39% or the ocean, allowing carbon to be absorbed from the atmosphere and deposited in the deep sea.