Nice article, to be clear though, corals do not actually glow in the dark. Florescence is when light is absorbed at one wavelength, and remitted at another, in the beautiful photo you showed the corals appear to be glowing due to the use of special UV lights and yellow filters. Some marine organisms, such as dinoflagellate algae, are able to glow and this is known as bioluminescence. We use the special UV lights and filters on night dives to observe minute changes in coral health, but also just because it is so amazing to see all the different neon colors from so many of the animals on the reef which fluoresce. One of my personal favorites are the scorpion fish, which blend perfectly into the reef in the day time, but appear a bright red under the UV light.