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Environmental Monitoring


March 2012 Issue

Arctic Sea Ice Remains Below Average, Except in Bering Sea
In January, Arctic sea ice extent averaged 13.73 million square kilometers, the fourth lowest January average in the satellite data record from 1979 to 2012 and 1.1 million square kilometers below the 1979 to 2000 average, the National Snow and Ice Data Center (NSIDC) reported in February.

The below-average ice extent applied to the Arctic's Atlantic side, particularly in the Barents Sea. In contrast, the ice extent on the other side of the Arctic, in the Bering Sea, was much larger than the average, amounting to the second-highest level for January in the data record. The increase in ice made for troublesome conditions for fishermen and a late-season resupply mission to Nome, Alaska, which was iced in by a storm in November, preventing its last barge of the season from delivering fuel. The Russian fuel tanker Renda, with the U.S. Coast Guard icebreaker Healy, completed delivery in January.

The high ice extent on the Bering Sea side compensated somewhat for the low ice extent on the Atlantic side, but the overall Arctic ice extent remained well below average. Arctic ice expanded 765,000 square kilometers in January, 545,000 square kilometers less than the month's average from 1979 to 2000.

The Arctic sea ice January growth rate was the slowest on record. Ice growth started strong in early January, then slowed mid-month and kept slowing throughout the month. NSIDC said the slow growth rate was probably due to winds from the south and west compressing ice in the Barents Sea and above-average temperatures and winds in the Sea of Okhotsk.

The linear rate of decline per decade for Arctic ice extent in January over the satellite record was 3.2 percent, NSIDC said. For more information visit nsidc.org.

BSEE, NOAA to Develop Arctic Version of ERMA
The Bureau of Safety and Environmental Enforcement (BSEE) and NOAA are partnering to develop a version of the Environmental Response Management Application (ER'MA) for the Arctic by this summer, the agencies announced in February.

The effort will help address numerous challenges in the region where more ship traffic and proposed energy development are increasing the risk of oil spills and chemical releases. ERMA is the same interactive online mapping tool used by federal responders during the Deepwater Horizon.

'Reconfiguring this application to meet the needs of responders in the remote marine Arctic environment could prove to be the most critical tool in effectively preparing for, responding to, and mitigating situations where limited assets, personnel and facilities exist,' said Monica Medina, NOAA principal deputy undersecretary for oceans and atmosphere.

The U.S. Arctic Research Commission came out in support of ERMA's further development. Fran Ulmer, chair of the U.S. Arctic Research Commission, said, 'An Arctic version of ERMA will greatly aid U.S. response capacity in the event of an oil spill or chemical release and I strongly support it. Now is the time to create useful tools like this.' For more information visit www.noaanews.noaa.gov.

Study Uses Satellite to Track Loggerhead Sea Turtles
Researchers have found two feeding hot spots for at least three different populations of loggerhead sea turtles in the Gulf of Mexico by using satellite tracking tags. One site is in the open waters off southwest Florida's coast, and the other is at the northern tip of the Yucatan Peninsula.

Loggerhead populations in the Gulf of Mexico have continued to decrease sharply in certain areas. The discovery of the two sites will enable marine planning and management for the endangered species, the U.S. Geological Survey said in February.

The goal of the study, published in Biological Conservation in January, was to synthesize tracking data for the three loggerhead populations as they moved through the Gulf of Mexico. Little has been known previously about loggerheads' habits at sea.

Researchers placed the satellite tags on female loggerheads after they came ashore to nest at beaches in the Florida Panhandle, Casey Key and Dry Tortugas National Park.

'Up until now, management actions that affect loggerheads have often focused on their limited time at nesting beaches or on fisheries regulations,' said Kristen Hart, U.S. Geological Survey research ecologist and leader of the study. 'Our findings open up important new options for marine habitat conservation and provide valuable geographic data that can be used to strategically locate marine reserves based on the best available science, as called for in the new National Ocean Policy.' For more information visit www.sciencedirect.com.

Blue Light Can Trigger Red Tides, Scientists Find
A team of researchers in the U.S. and Spain announced in February the discovery of the mechanism that triggers phytoplankton toxin release. These highly potent toxins are part of red tide formations, which are made of phytoplankton blooms that kill millions of sea creatures in coastal waters around the world. The causes of red tides remain unknown.

Algae, such as Karenia brevis, that proliferate and compile on the ocean's surface appear as a red tide. Karenia is a unicellular microalgae deadly to marine life and hazardous to human health because it produces brevetoxin, a neurotoxin that binds to nerve and muscle cells. The precise causes of algal blooms are still a mystery that has to do with fluctuations in ocean temperature, salinity and nutrients.

Karenia and other single-celled microalgae work like human secretory cells by storing active chemicals in membrane-lined microscopic vessels, the researchers found. Algae such as Karenia store toxins in these vesicles by caging them in a gel matrix. Exocytosis releases the toxins when stimulated by sunlight, particularly the blue part of the spectrum.

'Often, plants and animals release toxins as a defense mechanism,' said Verdugo. 'Whether this is the case in phytoplankton remains speculative. However, blue light stimulation implies that these cells must have a photoreceptor—most likely associated with the cell structures known as chloroplasts, which are responsible for photosynthesis. This is in fact one of the riddles we'll tackle next.' For more information visit www.newswise.com.


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