Microscopic organisms turn the Black Sea turquoise from space

The Black Sea is typically known for its dark, deep waters, but every spring and summer it undergoes a dramatic visual transformation. Massive blooms of microscopic organisms called coccolithophores multiply in such vast numbers that they change the color of the sea to a bright, milky turquoise. This shift is so pronounced that the swirling patterns are clearly visible to astronauts orbiting aboard the International Space Station.