The icy bow of the research ship CCGS Amundsen, on a wintery ice-sampling cruise through Arctic waters.LAURA ALFONSO-SAEZ
The Arctic winter is cold and dark everywhere. But under the sea ice, strange things happen. At the bottom of the food chain, phytoplankton, which fix inorganic carbon into usable sugars, don’t grow—there’s no sunlight for photosynthesis. Yet in these inhospitable conditions, some marine bacteria have found a surprising way to eke out an existence.
Heterotrophic bacteria, which normally eat the carbon they need to survive, have a problem if they are living underneath polar ice: how to survive the long winters, where food, in the form of photosynthetically derived organic carbon, is severely limited? While carbon fixation in the dark has been studied in the oxygen-scarce twilight zones of the deep ocean, it hasn’t been considered important in shallower, well-oxygenated waters. Laura Alonso-Sáez, ...
