though beautiful, these fluorescent blue patches of water are an indicator of a harmful algal bloom created by noctiluca scintillans, single celled organisms which become abundant when levels nitrogen and phosphorous from farm run off increase, and which proves toxic to the marine life that consumes it. the noctiluca also serve to deprive the water of oxygen, creating dead zones that are difficult for oceans to recover from.
while the evolutionary reason for their bioluminescence is still debated, varying from defensive purposes to communication to predatory strategy, the cause of this so called sea sparkle is better known; as the noctiluca float, movement in the water sends electrical impulses around a proton filled compartment inside the microorganisms, triggering a series of chemical reactions which ultimately activates luciferase, a protein that produces the neon blue light.
most marine bioluminescence is in the blue and green light spectrum, as these wavelengths pass furthest through seawater. interestingly, no known fresh water dinoflagellates have ever evolved bioluminescent abilities.