How deep do bioluminescent creatures live underwater?
Captain Nelson answers: Most of the common occurrences of bioluminescence in the ocean are observed right at the surface or in the surface layers (several meters to tens of meters, within the euphotic zone). In its most familiar form, bioluminescence, which is a biochemical reaction in certain marine organisms, appears as a bluish-green fluorescent glow in the water as the surface is disturbed by the bow wave or wake from a ship or by cresting or breaking waves. Bioluminescence is quite often observed on a ship itself, as most ships are equipped with a salt-water system for flushing toilets. If a toilet is flushed in a dark bathroom (called a “head” on ships) the toilet bowl will often glow because of the bioluminescent microscopic organisms in the sea water used for flushing. Bioluminescent displays may occasionally take on more spectacular forms, such as appearing as parallel lines or like spiraling spokes of wheels, of pulsating light that extend to the horizon. In the surface layer
