A scuba diver swims under ice hummocks of the White Sea. The strength of tides breaks the thick ice shield and creates majestic sculptures. The underwater sea world looks like a different planet with a green sky over your head. The greenish water color is caused not only by the properties of the water itself but also by microscopic planktonic algae—the basics of marine life. In the spring sunlight, planktonic algae start to reproduce. Billions of tiny organisms absorb the red and blue parts of sunlight, which they use for photosynthesis; that's why sea water becomes green. And the more phytoplankton living in the sea, the greater the proportion of green. The White Sea is one of the southernmost Arctic seas, so climate change affects it significantly.