Light is FILTERED BY THE ATMOSPHERE before it enters the water column
• At the water's surface, PHOTONS will be REFRACTED, REFLECTED and POLARISED
• Changes in the lighting characteristics are due to the DIFFERENTIAL ABSORPTION
OR REFLECTION OF PHOTONS of different wavelengths
• Water also ABSORBS DIFFERENT COLOURS SELECTIVELY. First the reds and oranges
disappear, later the yellows, greens and purples and last the blue
• In the DEEP OCEAN, the wavelength of light that is absorbed best is 470-480nm,
500-530nm in coastal water, and 550-560nm or longer in fresh water