Located off the northern coasts of Norway and Russia, the Barents Sea is rather shallow, with an average depth of 230 meters (750 feet). Yet, what it lacks in depth it more than makes up for in biological production, as the presence of the bloom indicates. Benefiting from cold, nutrient rich waters, the tiny marine plants that comprise phytoplankton are a key component of the region's ecosystem, serving as a food source for zooplankton, which in turn feed a host of sea life ranging from cod to whales. The colors in this image are the result of pigments, including chlorophyll, that the plants use to harness sunlight for photosynthesis. The brightest blue color is sometimes the result of a kind of phytoplankton called a coccolithophore that has a bright white calcium carbonate (chalk) covering. The brilliant colors are produced when the white mixes with the blue reflection off the water.