Up until last year, we had adecade of general ice loss in the
Arctic. This led to more open water and the earlierblooms noted here. As the ice retreats,the Arctic expands its food chain hugely.
After this winter, I am expectinga powerful reversal of this behavior, so we will have our eyes open forreports. We should have a late springbreakup. In
, the cherry blossoms are just nowbreaking out. No February bloom thisyear and no lost ski days. Vancouver
So all of
north America had a severe winter by any standard.
Yet what is important here isthat this work independently confirms the decadal change that took place in the
Scripps Oceanography Researchers Discover Arctic Blooms OccurringEarlier
Ice edge blooms often follow retreating ice, as shown here on July 5,2007, south of Wrangel Island in the eastern
.Satellite data captured by the NASA MODIS-Aquasensor, processed by Mati Kahru. Credit: Scripps Institution of Oceanography,UC Chukchi Sea San Diego
by Staff Writers
Warming temperatures and melting ice in the
Scientists at Scripps Institution of Oceanography atUC San Diego, along with colleagues in Portugal and Mexico, plotted the yearlyspring bloom of phytoplankton-tiny plants at the base of the ocean foodchain-in the Arctic Ocean and found the peak timing of the event has beenprogressing earlier each year for more than a decade. The researchers analyzedsatellite data depicting ocean colorand phytoplankton production to determine that the spring bloom has come up to50 days earlier in some areas in that time span.
The earlier Arctic blooms have roughly occurred in areas where iceconcentrations have dwindled and created gaps that make early blooms possible,say the researchers, who publish their findings in the March 9 edition of thejournal Global Change Biology.
During the one- to two-week spring bloom, which occurs in warm as wellas cold regions, a major influx of new organic carbon enters the marine ecosystem througha massive peak in phytoplankton photosynthesis, which converts carbon dioxideinto organic matter as part of the global carbon cycle. Phytoplankton bloomsstimulate production of zooplankton, microscopic marine animals, which become afood source for fish.
Mati Kahru, lead author of the study and a research oceanographer inthe Integrative Oceanography Division at Scripps, said it's not clear if theconsumers of phytoplankton are able to match the earlier blooms and avoiddisruptions of their critical life-cycle stages such as egg hatching and larvaedevelopment.
"The spring bloom provides a major source of food for zooplankton,fish and bottom-dwelling animals," he said. "The advancement of thebloom time may have consequences for the Arctic ecosystem."
Such a match or mismatch in timing could explain much of the annualvariability of fish stocks in the region.
"The trend towards earlier phytoplankton blooms can expand intoother areas of the Arctic Ocean and impact the whole food chain," say theauthors, who used satellite data from 1997-2010 to create their bloom maps.
Biology and BiogeochemistryProgram and the National Science Foundation provided financial support for theresearch. The satellite data were provided by the NASA Ocean Biology ProcessingGroup, ESA GlobColour group, the National Snow and Ice Data Center and theJapan Aerospace Exploration Agency. Kahru's coauthors include Greg Mitchell, aScripps Oceanography research biologist, Vanda Brotas of the University ofLisbon in Portugal and Marlenne Manzano-Sarabia of Universidad Autonoma deSinaloa in Mexico. NASA Ocean