Deep sea has an intense blue color. The light that penetrates the water changes its light intensity and its spectral composition by effect of selective absorption by water of the different wavelengths that make up the visible spectrum. The ultraviolet and infrared stop the first few centimeters of depth, then extinguished the red, orange, yellow, green and purple and blue that reaches greater depths.
When the light meets the surface of the sea a certain amount is reflected in the angle of incidence. Plus the angle of incidence approaches to 90º (ie perpendicular to the water surface) the higher the penetration and the less the reflected fraction. The angle of incidence varies with latitude with the hours of the day and with the seasons. In temperate areas at midday in August it arrives on the surface of a 150,000 LUX intensity lighting. Already in the midst of this intensity meter depth it has been halved. In the more transparent ocean waters 99% of the solar radiation is absorbed in the first 100-150 m.
“Everyone believes that the sea is blue”, below the surface his colors explodes into a thousand different forms of life. And the prerogative of the marine world, unlike the terrestrial animals, to communicate through the colors being the emission of sounds limited to very few species. In the seabed, with particular attention to the crystal clear waters of coral reefs, the color burst is at its best; the fish that live in these waters have a particular visual color type acuitŕ that allows them to perceive a considerable distance color signals. The fish colors represent a valuable contribution to their defense, in fact, a school of fish formats all from the same garish color prevents the predator to fix attention on a single in particular.
The Mediterranean is not, however, be less, thanks to the corals: white, yellow, red; red coral, the age-old blacks corals. With fish like redfish, monkfish, moray eel, amberjack, the sunfish, the giant grouper, black damselfish from fry are a deep electric blue; and crustaceans such as lobster depth, multiple types of sponges, cnidarians and echinoderms, “Mare Nostrum “is a kaleidoscope of colors and nuances even in the most inaccessible depths where it dominates the blue.
Author: Andrea Cirivasi