Science News plunges into the dark, icy depths to discover how it is that phytoplankton, which convert sunlight to energy, survive and even thrive under the ice in the long, lightless Arctic winter:
Achim Randelhoff, an oceanographer at Université Laval in Quebec City, and colleagues deployed autonomous submersible floats in Baffin Bay that can measure photosynthetic activity and algae concentrations underwater.
In February, when light was barely detectable under about 1.5 meters of snow-covered ice, Arctic phytoplankton begin growing and multiplying, the researchers report September 25 in Science Advances. The study suggests that springtime blooms are the culmination of an extended period of growth that starts in winter, not a singular burst of activity as was thought.
“Arctic phytoplankton are superefficient at using every little photon they can find,” Randelhoff says, but he was surprised that they could grow with such little light. As the months progressed and the sun rose higher, the team found that algal growth accelerated, reaching its peak growth rate for the year in April and May, despite the microorganisms still being covered by ice.
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You can read the Science Advances study here.