Have you ever noticed those magical twinkling lights that comes off the ocean on a mid-summer night? Believe it or not, this lovely display it is the product of one organisms defense mechanisms.
Hi, this is Iain MacLeod from New Hampshire Audubon, bringing you Something Wild.
When you visit one of New Hampshire's ocean beaches at night at this time of year, you can often observe magical displays of tiny, twinkling, living lights in the water.
This natural phenomenon is most often created by several types of bioluminescent, or light-creating, plankton. These microscopic organisms are everywhere in the oceans. Warm weather can trigger dense outbreaks of plankton, resulting in as many as two million cells per half gallon of water. That's when we are most likely to notice them.
These organisms use a chemical reaction to create light when they are disturbed. But why would an otherwise nearly invisible creature give away its location by generating light? It turns out that they use bioluminescence as an effective defense against predators. When a plankton cell is disturbed by a predator, it creates a flash of light. The flash might attract the attention of an even larger animal, such as a small fish. The fish is more likely to find and eat the predator instead of the wee plankton. So anything that tries to eat these creatures may end up as someone else's dinner! It's enough to make you lose your appetite, which is exactly its purpose.
Even animals not interested in eating bioluminescent plankton must take care with their own movements, because the ocean is like a minefield. Any inadvertent motion may set off an explosion of light which exposes the unlucky animal to hungry predators.
To see these organisms in action, visit a beach on a dark summer night. Watch for them flashing in the breaking waves. Or go for a midnight swim and watch the sparkles of living light you create in the water.
For Something Wild, I'm Iain MacLeod.
Something Wild is a joint production of New Hampshire Audubon, New Hampshire Public Radio, and the Society for the Protection of New Hampshire Forests.
If you have a natural history question that you would like answered on Something Wild, email us at somethingwild@nhpr.org
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For more information on bioluminescent plankton, including instructions on how to raise them in your own home or classroom, visit: http://siobiolum.ucsd.edu
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