The Southern Ocean around Antarctica is one of the key regions for understanding the climate system.
The Southern Ocean around Antarctica is one of the key regions for understanding the climate system. The photosynthesis-performing plankton there contribute significantly to controlling the carbon dioxide concentration in the atmosphere. But which factors favor or limit plankton growth? In the journal Nature Communications, researchers at GEOMAR Helmholtz Centre for Ocean Research Kiel have now published a study showing for the first time that, in addition to the micronutrient iron, manganese can play an important role. Among other things, the results have implications for understanding ice ages in the past.
The term plankton describes usually very small organisms that drift with the currents in the seas and oceans. Despite their small size, they play an important role for our planet due to their immense quantity. Photosynthesizing plankton, known as phytoplankton, for example, produce half of the oxygen in the atmosphere while binding huge amounts of carbon dioxide (CO2). Since the Southern Ocean around Antarctica is very rich in nutrients, phytoplankton can thrive there. It is therefore a key region for controlling atmospheric CO2 concentrations.
As other nutrients are abundant, scientists have so far assumed that the amount of the available "micronutrient" iron determines how well phytoplankton thrives or not in the Southern Ocean. Researchers from GEOMAR Helmholtz Centre for Ocean Research Kiel and the UK's National Oceanography Center have now published a study in the international journal Nature Communications showing for the first time that in some areas of the Southern Ocean, manganese, not iron, is the limiting factor for phytoplankton growth.
“This is an important finding for our ability to assess future changes, but also to better understand phytoplankton in the past,” says Dr. Thomas J. Browning of GEOMAR, lead author of the study.
Read more at Helmholtz Centre for Ocean Research Kiel (GEOMAR)
Image: The study is based on an expedition by the British research vessel RSS James Clark Ross, shown here before setting off from the Falkland Islands. (Credit: Thomas Browning/GEOMAR)
