When the extent of sea ice decreases, the production of phytoplankton in the Arctic increases. Researcher Thomas Zack – working with an international research team with scientists from Canada, the United States, Germany and Sweden – has discovered a new way to model the productivity of phytoplankton in the Labrador Sea. The study was published in Nature.
By means of algae growing in shallow waters in the Arctic, which live for several hundred years, researchers can now gain information on the growth of phytoplankton. Algae grow more when ice cover decreases, and the same is true for phytoplankton. Data is obtained in a way resembling dendrochronology, in which researchers gather data through tree-ring dating.
The extent of the ice cover in the Arctic is known through reports from the past 200 years. And researchers see that variations in phytoplankton growth are closely linked with the extent of sea ice. The extent of sea ice, and the associated productivity of plant algae in the Labrador Sea, is traced in this way back to 1640, which is the age of the oldest algae investigated.
“This is an extremely rich climate archive, and we’ve only begun to see some of the many layers of information,” says Thomas Zack, a researcher and senior lecturer at the Department of Earth Sciences.