Posted by: tpsciencefun | September 15, 2011

RED TIDE Alert!!

* What is a red tide and where does it come from??

* Have you seen the red tide in the ocean?

* Have you ventured down to the beach after dark to see the red tide light show?

I HIGHLY recommend you go ASAP as the red tide is causing the night waves to “light-up” when the microscopic organisms that make up the red tide are disturbed by ocean wave activity.  “When jostled, each organism will give off a flash of blue light created by a chemical reaction within the cell. When billions and billions of cells are jostled – say, by a breaking wave – you get a seriously spectacular flash of light. So please take the opportunity to go down to the beach tonight or tomorrow night to see one of nature’s most impressive light shows.

Or, if you’re too tired to go down after the sun goes down, get a clear drink bottle and take some of it home. Put it in a cool, dark place – a closet or a bathroom without windows. Then, after the sun goes down go in there and let your eyes adjust to the darkness. Then give the bottle a shake – you’ll see blue sparks from the dinoflagellate’s bioluminescence. Then start experimenting:  pour some on your arm, or on the countertop. Let some get sucked up into a towel. Or (this is the best) try adding vinegar. The acid makes the dinoflagellates release their bioluminescence chemicals all at once, giving a show similar to the finale of a 4th of July fireworks display. Unfortunately, like the 4th of July fireworks display, it’s terminal. That’ll be the end of the fun…. until you go and get more red tide water.” (Peter Franks, SIO)

To learn even more about the red tide check out the SIO’s Voyager question and answer given by Peter Franks, professor of biological oceanography and former TPES parent!!

Voyager: Why are there Red Tides?
(Question submitted by Maddy K., 16, June 20, 2011, from Manhattan Beach, Calif.)

(Answer by – Peter Franks, professor of biological oceanography, Integrative Oceanography Division
Scripps Institute Of Oceanography)

This is a surprisingly difficult question to answer. A “red tide” is an accumulation of plankton so concentrated that it colors the water. Many different types of plankton can create red tides, and they can have little in common with each other. Some of these organisms are relatively big, some are tiny. Some are photosynthetic, some are not. Some swim, some can’t. Some produce toxins, some don’t.

To form a red tide, plankton either has to grow to very high concentrations or somehow accumulate at a location – by swimming, for example. There are two ways of growing to high concentrations: grow faster or die slower.

Some red tide organisms can reduce their death rate by exuding toxins that repel predators or by forming groups so concentrated that predators avoid them. They may also use chemicals to inhibit the growth of other plankton, leaving more resources for themselves.

Plenty of nutrients are required to support the growth and high concentration of red tide organisms. Some red tide areas contain more nutrients than the waters the plankton originally grew in, which implies that they had to get their nutrients from somewhere else. This usually involves the organisms swimming into deeper, nutrient-rich water to take up nourishment and then swimming back up toward the surface. For these tiny organisms, this trip would be like us walking from San Diego to Los Angeles each night for dinner and then back again in the morning.

Many red tide organisms can swim. If they all swim to the same depth (such as the surface of the ocean), the concentration of organisms will increase to the point that they color the water. This is why red tides are often most apparent at midday – the organisms all swim up to the surface to photosynthesize, or get energy from the sun. Many red tides begin forming in thin, dense layers below the ocean’s surface where they are invisible to humans. Suddenly one day the plankton can appear at the surface even though most of their growth probably happened during the previous weeks.

Have your own question? Submit it by going to the link below.



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