Algae are tiny plant-like organisms that look like shapes, such as small “blobs” or rods under a microscope. To the human eye, they can live in large communities that appear to be floating masses or filaments (fibers) of green, brown, and yellow under the sea ice. Copepods are larger than algae and most species look like tiny shrimp with red, brown, and clear bodies. They are part of the diet of the Polar cod, a narrow fish that has adapted to the frigid waters of the Arctic Ocean and can grow to 11 inches in length, but they are typically much smaller. Mammals, like ringed seals, eat Polar cod. These seals have a thick layer of blubber that enables them to live and swim in the Central Arctic. Arctic foxes are another type of mammal that have adapted to living on the sea ice. They can be brown, but near the North Pole they are fluffy and white. This helps them blend into their surroundings. And of course, there are polar bears! These large creatures have thick fur and fat layers to keep them warm and camouflaged while they travel over the sea ice and swim in the cold waters between ice floes.
When I was on the MOSAiC Expedition last fall and early winter, I saw clumps of algae in sea ice cores we collected, copepods in seawater samples, cod fished by some of the ecologists on board, and even polar bears. I was very excited to see all these animals, mostly because I am fascinated by how living beings can thrive in the cold and dark Arctic environment. I was warm in my thick parka jacket when I was working on the sea ice, but I could not last for more than several hours, while these animals live here 24/7!
