The hard rocklike material on which the living algae Clathromorphum compactum sits are layers of calcified crusts the algae deposit year after year. These “red rocks” grow in shallow water (49 to 55 feet deep) and are widely distributed in the Arctic and sub-Arctic Oceans. Scientists from the University of Toronto, the Smithsonian and other research organizations have recently discovered how to use these crusty layers to track changes in Arctic sea ice over centuries. Each year C. compactum can lay down a crust one-tenth to two-tenths of a millimeter thick. “They grow very slowly so if you get a specimen that is 8 or 9 inches thick you are talking about something that is well over 1,000 years old,” explains Walter Adey, algae expert at the Smithsonian’s National Museum of Natural History. When viewed under a scanning electron microscope the layers offer an archive of the levels of sea ice in the Subarctic dating back centuries. This newly tapped ‘archive’ shows a dramatic decrease in ice cover during the last 150 years.
You might also like:
- Ancient algal ‘tree rings’ show dramatic decline in Arctic and sub-Arctic sea ice
- Climate change conundrum: Invasive reed makes much more methane
- The HSBC Climate Partnership is a five-year partnership between HSBC, The Smithsonian, The Climate Group, Earthwatch Institute and WWF to inspire action on climate change.
- On the Chesapeake Bay, Smithsonian plant physiologist Bert Drake has been studying one wetland’s response to climate change for more than two decades.
- Work of 19th-century oologists enables researcher to track climate change with duck eggs