29 Jun 2012

No Ocean Necessary: Hands-on Science Activities for Beach Lovers

I grew up on the Eastern seaboard, so for me, summer means sand, surf, and soggy french fries from a red-striped paper box. It also means a long walk along the shore, picking up this and that, discovering something new every time. Last week, on New York's fabulous Jones Beach (an my old stomping grounds), we came across some sea lice on the beach - something I'd never seen in countless visits there.

Sea louse

Seeing this critter made me think about how you believe you know something, and then, much much later on, discover that what you thought you knew, about a person, a place, a fact, is incomplete or just plain wrong. Up until last week, my mental picture of Jones Beach did not include sea lice.  I now have had to modify that inner vision to include this new piece of data.

This is of course not the first time in my life I've had to revise my thinking on a subject. This past winter, while researching The Big Green Book of the Big Blue Sea,  I discovered that everything I thought I knew about pearls was wrong. No, they are not made by oysters when a bit of grit gets into their shell and irritates the lining.


You, like me, probably learned this fact aeons ago. How could it - we -  be wrong?

Even worse, the true cause of pearl formation has been known since 1856. People have been repeating incorrect information and spreading it for well over a hundred years. Jeesh.

So what does cause a pearl to form, if not a bit of grit? "The most beautiful pearl is only the brilliant sarcophagus of a worm," said Raphael Dubois in 1901. And in fact, the pearl is a method for entombing a parasite that has invaded the mollusk's shell. Slap it with a liquidy goo that soon hardens, and voila, the pest is neutralized.

One of the fun hands-on activities in The Big Green Book of the Big Blue Sea is making a real pearl of your own. Since finding and working with parasites is kind of yucky, I suggest you start the pearl the way I did - with a fake parasite/piece of grit. I used a tiny balled-up wad of paper. Over a period of several weeks, I coated the wad with layers of pearly white nail polish, letting the pearl dry between coats. Turn it over and repeat until you have a pearl like this one - pretty enough to wear, and not at all yukky.

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