Voyage into darkness

Marine biologists venturing into the polar night—the four winter months of the year when the Arctic sees no sunlight—are finding wondrous discoveries and rewriting the biological textbooks. Arctic dogma has held that the region is mostly dead in the winter, with organisms either dormant or migrated out of the polar region. But in recent journeys scientists have discovered zooplankton in all phases of reproduction, cod actively hunting for zooplankton, and six species of birds actively foraging, including little auks; one guillemot had recently swallowed 214 krill. Researchers are uncovering new rules that govern the ecosystem, including the fact that krill may migrate according to the phases of the moon, and the possibility that not only cycles of temperature, but also light, drive ecosystem change in the north.