Subscribe free to our newsletters via your
. 24/7 Space News .




ICE WORLD
Surviving without ice
by Staff Writers
Newark, DE (SPX) Sep 17, 2012


Apherusa glacialis in situ in sea ice.

With sea ice in the Arctic melting to record lows in summer months, marine animals living there face dramatic changes to their environment. Yet some crustaceans, previously thought to spend their entire lives on the underside of sea ice, were recently discovered to migrate deep underwater and follow ocean currents back to colder areas when ice disappears.

"Our findings provide a basic new understanding of the adaptations and biology of the ice-associated organisms within the Arctic Ocean," said Mark Moline, director of the University of Delaware's School of Marine Science and Policy in the College of Earth, Ocean, and Environment. "They also may ultimately change the perception of ice fauna as imminently threatened by the predicted disappearance of perennial sea ice."

Moline, Jorgen Berge of the University of Tromso and Norwegian colleagues found the crustaceans, specifically amphipods Apherusa glacialis that resemble small shrimp, well below sea ice during a rare winter, nighttime research expedition to the Fram Strait and Eurasian section of the Arctic Ocean. They determined that the crustaceans migrate downward as part of their life cycles and ride deep-ocean currents toward the North Pole.

The crustaceans' travels appear to be an adaptive trait that both increases survival during ice-free periods and enables them to be retained in the Arctic Ocean.

The scientists refer to their findings as the "Nemo hypothesis," based on an analogy to the Disney movie Finding Nemo in which Nemo's father uses deep-ocean currents for transportation. In a similar mechanism, Arctic crustaceans detached from melting sea ice move into depths where the northernmost branch of the Gulf Stream System effectively transports them back into the Arctic Ocean.

Previously, these organisms were generally considered to be passively exported either out the Fram Strait or down to inhabitable depths when released from melting sea ice - either of which would be life-threatening outcomes as they lost the habitat on which they depend to survive.

"Through the Nemo hypothesis, we offer a new and exciting perspective that, although still based on a limited dataset, might change our perception of the ice-associated organisms and their future in an Arctic Ocean potentially void of summer sea ice within the next few decades," Berge said.

From an evolutionary perspective, the migration may be an adaptation that allowed survival in a more seasonally ice-covered Arctic, as experienced several times during the last 12,000 years. Some reports indicate that the Arctic Ocean lacked summer sea ice as late as 8,000 years ago.

The findings may help explain how ice-associated organisms can survive in large populations in the Arctic when their habitat is annually reduced by up to 80 percent in the summer before re-forming in the early winter.

"We believe that this is an important contribution towards a more comprehensive understanding of potential consequences of a continued warming of the Arctic and the predicted loss of summer sea ice," Berge said.

The article was published in Biology Letters online on Sept. 12. The work was funded primarily by the Research Council of Norway, with support for Moline provided by the U.S.-Norway Fulbright Program through his role as Distinguished Arctic Chair.

.


Related Links
University of Delaware's School of Marine Science and Policy
College of Earth, Ocean, and Environment
Beyond the Ice Age






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








ICE WORLD
Sailboat navigates once-frozen Arctic waterway
Montreal (AFP) Sept 11, 2012
A three-man sailing expedition for the first time has navigated the once-frozen Northwest Passage, a perilous Arctic route made accessible only because of melting caused by global warming. The Swedish sailboat, the 9.4 meter (31 foot) Belzebub II, navigated through McClure Strait, northernmost waterway on the edge of the Canadian Northwest Territories. The crew - American Morgan Peissel ... read more


ICE WORLD
Remains of astronaut legend Neil Armstrong buried at sea

Memorial service honors 'man on the moon' Armstrong

Chandrayaan II may be delayed, says ISRO Chief

First man on moon to be buried at sea: Armstrong family

ICE WORLD
Squyres Warns Congress of Threats to Mars Program

India to launch Mars mission in 2013: official

Aging Mars rover discovers geological mystery

Mars Rover Curiosity Arm Tests Nearly Complete

ICE WORLD
Mankind's messenger at the final frontier

35 years on, Voyager 'dancing on edge' of outer space

Space-age food served up with seeds of success

Africa eyes joint space agency

ICE WORLD
Tiangong Orbit Change Signals Likely Date for Shenzhou 10

China Focus: Timeline for China's space research revealed

China eyes next lunar landing as US scales back

China unveils ambitious space projects

ICE WORLD
Europe's ATV-3 Spacecraft to Readjust Space Station's Orbit

NASA Offers Opportunity to Use Communications Testbed on Space Station

Japanese Freighter Undocks From Space Station

Woman takes command of ISS after crew return

ICE WORLD
Russian rocket sends European weather satellite into orbit

ISRO's 100th space mission blasts off, PM witnesses historic event

SES signs three satellite launches with SpaceX

S. Korea to make third rocket launch bid in October

ICE WORLD
Two 'hot Jupiters' found in star cluster: NASA

Planets Can Form in the Galactic Center

Birth of a planet

A Hot Potential Habitable Exoplanet around Gliese 163

ICE WORLD
Appeals court suspends suit on Google book scanning

Apple gets record 2 million iPhone 5 orders

European industry develops space safety radar

Nano-velcro clasps heavy metal molecules in its grips




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement