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Massive phytoplankton blooms under Arctic sea ice
Kevin R Arrigo1, Donald K Perovich, Robert S Pickart
1Department of Environmental Earth System Science, Stanford University, Stanford, CA 94305, USA. arrigo@stanford.edu
Science (New York, N.Y.)
|June 9, 2012
Summary
A massive phytoplankton bloom was discovered under solid sea ice in the Arctic Ocean. This finding challenges previous assumptions and suggests Arctic primary production may be significantly underestimated.
Area of Science:
- Oceanography
- Marine Biology
- Arctic Research
Background:
- Phytoplankton blooms in the Arctic Ocean were traditionally believed to occur only in ice-free waters.
- Thinning sea ice and increased melt ponds have enhanced light penetration in Arctic shelf regions.
Purpose of the Study:
- To document and characterize a massive phytoplankton bloom occurring beneath consolidated pack ice in the Chukchi Sea.
- To assess the implications of under-ice blooms for Arctic primary production estimates.
Main Methods:
- In-situ observation and sampling of a phytoplankton bloom under thick sea ice.
- Measurement of phytoplankton biomass, growth rates, and primary production.
- Analysis of environmental factors influencing light transmission.
Main Results:
- A substantial phytoplankton bloom, dominated by diatoms, was identified far from the ice edge, under consolidated pack ice.
- High rates of diatom growth and primary production were recorded within the under-ice bloom.
- Increased light transmission due to thinning ice and melt ponds facilitated the bloom.
Conclusions:
- Massive phytoplankton blooms can occur beneath solid Arctic sea ice, contrary to previous understanding.
- Under-ice blooms may be more prevalent on nutrient-rich Arctic shelves.
- Current satellite-based estimates of Arctic primary production likely underestimate actual values significantly, potentially by up to tenfold.
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