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Expedition Discovers Huge Sub-Ice Arctic Phytoplankton Bloom

June 7, 2012

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redOrbit Staff & Wire Reports

NASA officials announced on Thursday that an expedition they sponsored had uncovered a massive bloom of phytoplankton in the ice-capped waters of the Arctic Ocean — a discovery which the U.S. space agency has called “as dramatic and unexpected as finding a rainforest in the middle of a desert.”

The findings, which came as part of Impacts of Climate on EcoSystems and Chemistry of the Arctic Pacific Environment (ICESCAPE) expeditions held during the summer of 2010 and 2011, involved punching through three-foot thick sea ice and discovered waters far richer in microscopic marine plant life than any other ocean region in the world, NASA said. That discovery uncovers new consequences of the Arctic’s warming climate, while also providing a vital clue towards understanding the impact of climate change on the region’s changing ecology.

Among those on the ICESCAPE team responsible for the discovery were scientists from Woods Hole Oceanographic Institution (WHOI), who, in a separate announcement, said that prior to these findings, experts believed that sea ice blocked sunlight and limited the growth of microscopic aquatic plant life located below the thick sheets. However, what they actually discovered was four-times the amount of plankton as found in nearby, ice-free bodies of water.

“The bloom extended laterally more than 100 kilometers (62 miles) underneath the ice pack, where ocean and ice physics combined to create a phenomenon that scientists had never seen before,” the WHOI press release said.

They added that the study, which will be published in Wednesday’s edition of the journal Science, “concluded that ice melting in summer forms pools of water that act like transient skylights and magnifying lenses,” and that those pools “focused sunlight through the ice and into waters above the continental shelf north of Alaska, where currents steer nutrient-rich deep waters up toward the surface” and where “phytoplankton under the ice were primed to take advantage of this narrow window of light and nutrients.”

According to NASA, ICESCAPE researchers observed blooms beneath the ice that extended from the edge of the sea ice to more than 70 miles into the ice pack during the Chukchi Sea leg of the mission, which took place in July 2011. They analyzed ocean current data and discovered that the blooms had originated beneath the frozen waters, and had not drifted there from open water.

Furthermore, the phytoplankton were said to be more active than those living in open waters, doubling their numbers more than once each day beneath the ice versus every two or three days in warmer seas, they added.

“Part of NASA’s mission is pioneering scientific discovery, and this is like finding the Amazon rainforest in the middle of the Mojave Desert,” Paula Bontempi, the space administration’s ocean biology and biogeochemistry program manager in Washington, said in a statement. “We embarked on ICESCAPE to validate our satellite ocean-observing data in an area of the Earth that is very difficult to get to. We wound up making a discovery that hopefully will help researchers and resource managers better understand the Arctic.”

“If someone had asked me before the expedition whether we would see under-ice blooms, I would have told them it was impossible. This discovery was a complete surprise,” added Stanford University’s Kevin Arrigo, the lead author of the study and head of the ICESCAPE project. “At this point we don’t know whether these rich phytoplankton blooms have been happening in the Arctic for a long time and we just haven’t observed them before. These blooms could become more widespread in the future, however, if the Arctic sea ice cover continues to thin.”


Source: redOrbit Staff & Wire Reports