Greenland adds nutrient to ocean as a side-effect of thawing

Greenland’s thaw, which is raising world sea levels, is also adding about 300,000 metric tonnes of iron a year to the North Atlantic, based on projections from the study from the muddy melt water of three glaciers in the southwest. That is similar to the amount of iron blown into the region as dust by winds. Scientists say that iron is a vital nutrient and that a lack of the element in parts of the oceans limits growth of everything from tiny plankton to fish and whales.

“We suggest that glacial runoff serves as a significant source of bio-available iron to surrounding coastal oceans,” the scientists, mainly at the US woods Hole Oceanographic Institution (WHOI), wrote in the journal Nature Geoscience. “We would expect this glacial contribution of iron to the North Atlantic Ocean to continue to increase under future warming scenarios”, they added. The findings show that “as glaciers and ice sheets melt there may be other effects than just increased sea level,” said Maya Bhatia, who was leader of the study at WHOI and the Massachusetts Institute of Technology.