A new study reveals the extent to which airborne dust in the Southern Ocean is fueling plankton blooms that absorb our emissions.
A new study reveals the extent to which airborne dust in the Southern Ocean is fueling plankton blooms that absorb our emissions.
In total, the world’s oceans take up around a third of our carbon emissions, and of that, the Southern Ocean absorbs the lion’s share. Most of that carbon dioxide simply dissolves into the water, but some is consumed by phytoplankton and buried at sea. When plankton die, they sink deep into the ocean, locking away carbon for decades or centuries.
Like us, phytoplankton need iron, and in the Southern Ocean they draw a good measure their iron from dust that arrives on westerly winds from Australia, Patagonia, and southern Africa. Until now, however, it wasn’t clear how much phytoplankton depend on this dust.
To find out, scientists deployed a fleet of floating robots to measure levels of nitrate, another key nutrient for phytoplankton, at more than 13,000 locations across the Southern Ocean. When the level of nitrate dropped, they inferred, it was because a plankton bloom had gobbled it up.
Read more at Yale Environment 360
Image: A phytoplankton bloom off the coast of Argentina. (Credit: NASA)
