Hidden ecosystem discovered after huge crack forms in Antarctic glacier
'Sea stars as big as hubcaps, colorful sponges and feathery sea pens' are just some of the marine creatures found.
Tue, Apr 26, 2011 at 05:59 AM
MERTZ GLACIER: An iceberg's crash into the Mertz Glacier last year caused the huge swathe of ice to crack. (Photo: Wiki Commons/GNU)
One of nature's great spectacles occurred early last year when a 60-mile-long iceberg collided with the Mertz Glacier in East Antarctica, causing a section of the glacier to crack off into the Southern Ocean. The event has now given scientists a rare opportunity to peer into ocean water previously covered in hundreds of meters of ice, and the results have been nothing short of stunning, according to Wildlife Extra News.
Currently the once-dark expanse of ocean is awash in an intense bloom of phytoplankton, and deep on the ocean floor a whole ecosystem previously hidden from view has been exposed. The diverse array of creatures being seen for the first time include "sea stars as big as hubcaps, colorful sponges and feathery sea pens."
"Despite no natural light reaching the area for nearly 80 years, nutrient-rich water has supported a proliferation of vulnerable marine life, including sea stars the size of hubcaps," said Martin Riddle, one of the lead researchers on the scientific expedition.
The thick blanket of phytoplankton has bloomed due to the increase in sunlight, as well as due to an abdundance of iron dust rapidly being released by the melting glacier, which fuels the tiny organisms.
"Suddenly the geometry of Antarctica has changed," said Steve Rintoul, an oceanographer with the Antarctic Climate and Ecosystems Cooperative Research Center at CSIRO in Tasmania. "It was a sort of natural experiment, where the caving of the glacier tongue was not caused by climate change. This is a natural event, so nature has done the experiment for us this time."
Although the event was natural, it could still have monumental effects on worldwide weather, ocean circulation and marine life. A major reason for the scientific expedition was to study how the ecosystem might respond to such large-scale changes, as well as to conduct experiments that may help scientists better understand climate change.
Perhaps the biggest concern surrounding the event is the rapid decrease in water salinity in the area, due to the melting of the ice as it floats into warmer waters. The reduction in salinity in combination with a rise in ocean temperature could drastically affect future circulation of the Thermohaline around Antarctica, since the area around the Mertz Glacier is one of Antarctica's major dense salty water formation zones.
Basically, as salinity decreases and temperature increases, water becomes less dense. That means that the circulating currents that bring cold, nutrient-rich water to the ocean's depths could halt, which would have worrisome results for marine life all around Antaractica, and possibly around the rest of the world's oceans, too.
So while the current explosion of life under the ice crack is impressive, that diversity could be short-lived. It is hoped the information gathered on the Mertz voyage will help support Australia's application for a Marine Protected Area (MPA) in the Mertz region. For now, though, the moment is one of great discovery.