Posted by admin | 02.01.2013 | Marine Science

Ocean of Light

Bioluminescence is defined as the production and emission of light by living organisms. It is often referred to as “cold light” as the reaction will produce a visual light but rarely generates any thermal radiation. The light is a form of natural energy released by chemical reactions within the organism. This ability to produce light without producing heat protects the organisms from literally burning u (ever touched a light bulb?!). This phenomenon is exhibited in marine vertebrates, invertebrates,fungi, microorganisms, and terrestrial animals. A terrestrial example that we are all probably familiar with is the firefly or lightening bug.

Fireflies contain specialized cell in their abdomen that contain a chemical called luciferin – this is also where an enzyme know as luciferase originates. Both of these are essential to light production.

The luciferin will coalesce with adenosine triphosphate (aka the ATP which is found in all cells) to form luciferyl adenylate and pyrophosphate (PP_i) on the surface of the luciferase enzyme.

luciferin + ATP ————-> luciferyl adenylate + PP_i

Oxygen than interacts with the luciferyl adenylate to produce oxyluciferin and adenosine monophosphate (AMP).

uciferyl adenylate + O₂ ————-> oxyluciferin +AMP + light

Light results from the oxyluciferin and AMP being released from the enzyme’s exterior surface. Fireflies typically give off wavelengths of light between 510 and 670 nanometers which produces a soft yellow to reddish green color.

Bioluminescence is uncommon in terrestrial animals, conversely ninety percent of known deep-sea marine life bioluminesce. The majority of marine organisms that bioluminesce emit blue or green because those particular wavelengths transmit throughseawater more clearly than other colors.

Bioluminescence has several functions depending on the species. Mimicry, mating, distraction, repulsion, communication, and illumination are the most common ways bioluminescence is utilized in the animal kingdom. The deep sea angler fish uses a glowing lure to attract prey, fireflies and ostracods (small crustaceans that resemble shrimp) depend on it to initiate mating, while some squid species can expel a cloud of bioluminescent material to confuse potential predators long enough to escape.

There are numerous and varied marine species that employ the use of bioluminescence to survive, but for most of us on dry land running across these glowing creatures of the deep in unlikely. Fortunately for those interested in experiencing an ocean alight (and aren’t necessarily willing dive into the deep) there is one tiny organism that is known for putting on a pretty grand display.

Marine plankton known as dinoflagellates sometimes give off an eerie dull glow and often a flash of green light when they are disturbed. Dinoflagellates are commonly found in surface waters, but rarely in the high concentrations as displayed in Bahia Fosforescente, Puerto Rico where a single paddle stroke can set off an underwater fireworks show. Though scientists aren’t exactly sure why dinoflagellates glow, most suspect it has to do with predation and it iscertainly a sight to behold.

So remember, the next time you are walking along a peaceful beach at night and the entire ocean seems to be romantically aglow it all because of some slightly agitated microorganisms.