The research was part of the AWI MOSAiC expedition, which had the German icebreaker Polarstern spend a year drifting through the ice of the Arctic Ocean. The measurements were collected at 88° northern latitude below a layer of snow-covered sea ice.
Even as measurements were taken only a few days after the end of a month-long polar night, biomass production had begun, which requires photosynthesis. The microalgae had about one hundred thousandth of the amount of light of a sunny day on the Earth’s surface, which was measured by sensitive light sensors in the ice and water.
Despite the studies being related to the Arctic, Hoppe said that the results can display how powerful photosynthesis could be within other ocean environments that require highly adaptive behaviors from organisms. Deep ocean habitats that were once thought to be uninhabitable for photosynthesizing organisms could be much larger than previously believed.
Further reading about the research project and the MOSAiC expedition can be found through AWI, and the full paper can be downloaded as a PDF from Nature Communications.