The ice is melting: how do trace metals in the ocean influence the Antarctic marine ecosystem and global climate?

Though often regarded as toxins, metals are required as nutrients for the growth of all organisms. Metals form the reactive centres of enzymes, enabling these to perform biochemical functions, such as oxygen-transport or photosynthesis. As such, trace metals are central to the health of individual organisms as well as entire ecosystems. In the open ocean, the base of the food web is formed by unicellular algae, known as phytoplankton. For certain ocean regions such as the Southern Ocean, trace metals regularly limit the amount of phytoplankton that can grow, and thus the amount of life that can be sustained. Since phytoplankton take up CO2 from the atmosphere, trace metals influence atmospheric CO2 levels and thus the global climate. However, only limited knowledge exists about these algae-trace metal interactions and their susceptibility to a changing climate. Coastal Antarctica harbours large phytoplankton blooms that sustain Antarctica's key higher organisms and are a crucial sink of anthropogenic CO2. This region experiences dramatic changes as temperatures are rising and glaciers are melting. This project will reveal what role trace metals play in the Antarctic ecosystem and give us the ability to predict how its role in global climate will change under future climate scenarios.