A Blue View is a weekly perspective on the life aquatic, hosted by National Aquarium CEO John Racanelli.
From the smallest plants and animals invisible to the human eye to entire ecosystems, every living thing depends on and is intricately linked by water.
Tune in to 88.1 WYPR every Tuesday at 5:45 p.m. as John brings to the surface important issues and fascinating discoveries making waves in the world today.
January 2, 2014: Inside Bioluminescence
In the ocean’s deepest reaches, sunlight cannot penetrate, and yet, there is light. From softly glowing to dazzlingly brilliant, it is not the light of humans and their machines. It is called bioluminescence—literally, “living light”—and it provides a bewildering variety of species the means to seek prey and elude predators in a world as alien to us as space.
Check out our infographic on this fascinating phenomenon:
Bioluminescence occurs when living creatures convert chemical energy to light energy, resulting in the production and emission of light. Here in the mid-Atlantic, we experience bioluminescence in our own backyards on many a summer evening. Fireflies are among the few terrestrial species that glow, joined by certain species of bacteria, insects, and fungi. Beyond these, there are few other bioluminescent animals found on land.
Under the sea, however, it is a remarkably different story. An estimated 90 percent of deep-sea marine creatures are able to produce bioluminescence in some way. Most emit blue or green hued light, though some creatures employ a red-light strategy—taking advantage of the fact that red is the first color in the spectrum to be refracted.
In the deep, where food is scarce and conditions unforgiving, bioluminescence is critical to the survival of countless aquatic species.
For those defending themselves against predators, bioluminescence can be used to distract or even divert attention. Bomber worms actually eject glowing green masses that redirect a predator’s attention!
Other marine animals use the light as a lure to find food. Consider the anglerfish, which has a light rod protruding from its head. This light coaxes prey to come closer, at which point the anglerfish snaps its impressive jaws around its meal. Certain squids flash light to stun their prey.
In one of the most fascinating uses of bioluminescence, counter-illumination, the light pattern on the bottom of a fish replicates the appearance of faint sunlight from above, so the fish is invisible to predators looking for food from below.
For all we’ve learned, we still known very little about how these mysterious creatures use their bioluminescent capabilities, and access to these incredible animals is a challenge for researchers. The very qualities that make them so fascinating also make them almost impossible to study.
Scientists from the National Oceanic and Atmospheric Administration and other organizations are researching this deep frontier in an effort to better understand the 90 percent of the ocean yet unexplored.