Carbon dioxide, a greenhouse gas, contributes to the effect called global warming—defined as an increase in the average global temperature, over the past few decades and projected to continue into the future, of the Earth’s surface and near-surface atmosphere and oceans.
Marine life such as phytoplankton, krill, algae, and seabirds (including Antarctic fulmars and Cape Petrels) have set up residences on and about these icebergs, and large numbers of fish are found in the waters near the icebergs. These icebergs have broken away from large ice shelves in Antarctic due to rising temperatures at the South Polar Region.
U.S. oceanographer Kenneth L. Smith, Jr., of the Monterey Bay Aquarium Research Institute, states that these free-floating icebergs have been found in the Weddell Sea (a part of the Southern Atlantic Ocean located southeast of Cape Horn)—numbering in the thousands. Some of the larger of these floating icebergs are 20 kilometers (12 miles) in length and over 40 meters (130 feet) high. One particular iceberg went about 300 meters (1,000 feet) into the ocean.
Smith led a scientific study to research the effect these floating ecosystems have on the ecology and chemistry of the ocean around these icebergs. The research team found a thriving community of marine life in and around these icebergs. In fact, an abundance of marine life have accumulated as far out as several kilometers from the icebergs.
The marine creatures are attracted to the icebergs because as the icebergs break away from the Antarctic ice shelves they contain soil, nutrient-rich dirt, dust, and other trace nutrients. These materials are released as the icebergs melt and are eaten by the various marine creatures in the vicinity.
Smith states, “One important consequence of the increased biological productivity is that free-floating icebergs can serve as a route for carbon dioxide drawdown and sequestration of particulate carbon as it sinks into the deep sea.”
In other words, the icebergs are helping to absorb carbon from the atmosphere, which is then released into the oceans and eaten by marine life. The ecosystem of the icebergs use photosynthesis to remove carbon from the atmosphere and convert it into plants and other organic carbon matter that eventually ends up in the ocean—to be eaten by marine life.
Photosynthesis is the production of starch, glucose, and other products (originally in the form of triose phosphates) from the interaction of sunlight, carbon dioxide, and water.
The Smith team discovered with satellites images that 962 icebergs were found in their study area of about 10,360 square kilometers (4,000 square miles). They concluded that nearly 40% of the entire region could contain floating icebergs and their associated carbon-eating ecosystems.
Their study used biological, chemical, and physical measurements, along with satellite images, to produce a comprehensive study of individual icebergs and their associated marine communities.
The Smith study concludes that these complex ecosystems of “floating islands of ice” could remove a significant amount of carbon dioxide from the atmosphere within the local area. Its contribution to the removal of carbon on a global scale is uncertain, however. More research will be necessary to discover its more long-reaching affects, if any.
The Smith study is found, the week of June 21, 2007, in the online version of the journal Science. It is entitled “Free-Drifting Icebergs: Hot Spots of Chemical and Biological Enrichment in the Weddell Sea”. The authors include Smith, Bruce H. Robison, John J. Helly, Ronald S. Kaufmann, Henry A. Ruhl, Timothy J. Shaw, Benjamin S. Twining, and Maria Vernet.