Glaciers transport desert dust to polar plankton
The coastal regions downstream from glaciers are highly productive ecosystems, one example of which is the large summer phytoplankton bloom in the Labrador Sea. One possible explanation of this high productivity is that meltwater from glaciers is supplying iron to these areas. Iron (Fe) is an essential micronutrient for marine phytoplankton, and in large areas of the world’s oceans its availability is a limiting factor for growth for these primary producers, on which the marine food web depends. Iron supply is also a critical factor in dictating the strength of the ocean ‘biological pump’, which affects concentrations of carbon dioxide in the atmosphere, and hence the global climate.
Glaciers and ice sheets are a significant source of nanoparticulate iron, but its bioavailability and therefore importance to the marine environment is not yet well understood. A team of researchers from the UK and Germany have used high-resolution imaging and spectroscopy to investigate the amount and type of iron present in glacial sediments.