Mysterious Green Swirls Spotted Off Antarctic Coast | Phytoplankton Blooms

These green swirls were spotted off the coast of East Antarctica on Feb. 27 by NASA's Terra satellite.

CREDIT: NASA image courtesy Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response Team

Late last month, a NASA satellite flying over East Antarctica spotted swirls of green off the Princess Astrid Coast that left experts wondering just what it was.

Such a pattern usually indicates a bloom of tiny plantlike organisms called phytoplankton, which form the base of the ocean food chain.

Such blooms are common along the Antarctic coast, but typically form in early December, in the austral spring, not so late in the summer season, according to experts consulted by NASA.

"It doesn't look like a phytoplankton bloom to me," Stanford University marine biologist Kevin Arrigo, who led NASA's ICESCAPE expeditions to the Arctic in 2010 and 2011, told NASA. "The spatial pattern resembles the sea ice too closely. It looks suspiciously like green sea ice. Plus, it’s very late for such a bloom in the Antarctic."

NASA MODIS: Antarctic Algae Bloom Can be Seen from Space

A field of bright green algae in Antarctica could be seen from space.

Australian scientists spotted the algae captured in satellite pictures.

The scientists believe that the growth has been caused by a build-up of iron, most likely caused by snow that blew into the waters.

The algae bloom, which is about 200 kilometres wide and 100 kilometres long, was photographed from the Modis instrument on Nasa's Terra Satellite, at least 650 kms from the Earth.

Mark Curran from the Australian Antarctic Division reported that Antarctica's snow contained small amount of iron.

He said during summer, Amery Ice Shelf in East Antarctica had experienced strong winds which would have blown the snow into the ocean.

"Very, very tiny amounts of iron act as a nutrient," he said.

"Usually algae in this region are iron limited and so when they get a small amount of iron and they have everything else they need, that's enough for them to bloom," he added.

The scientists said that the algae had been there for more than three weeks and would not cause any damage to the environment.

They said it would disappear automatically.

NASA: Blue Green Algae bloom Lake Atitln, Guatemala

A large bloom of cyanobacteria, more commonly known as blue-green algae, can be seen on Guatemala's Lake Atitln in this simulated-natural-colour image taken from space by NASA's Terra satellite

Picture: NASA / BARCROFT