From UPSC perspective, the following things are important :
Prelims level : Milky Sea Phenomenon
Mains level : NA
Some researchers would use satellites to study the elusive milky sea phenomenon.
What is the Milky Sea?
- Milky seas, also called mareel, is a luminous phenomenon in the ocean in which large areas of seawater appear to glow translucently (in varying shades of blue).
- Such occurrences glow brightly enough at night to be visible from satellites orbiting Earth.
- They are a rare nocturnal phenomenon in which the ocean’s surface emits a steady bright glow.
Why do they glow?
- Luminous bacteria cause the particles they colonize to glow.
- The purpose of this glow could be to attract fish that eat them.
- These bacteria thrive in the guts of fishes, so when their populations get too big for their main food supply, a fish’s stomach makes a great second option.
How do they occur?
- It is typically caused by Noctiluca scintillans (popularly known as “sea sparkle”), a dinoflagellate that glows when disturbed and is found in oceans throughout much of the world.
- Once their population gets large enough – about 100 million individual cells per millilitre of water – a sort of internal biological switch is flipped and they all start glowing steadily.