June 20th, 2005

glowy things

(no subject)

We're having another "red tide". Bioluminescent dinoflagellates for everybody! This happens once or twice a year, in the spring and/or fall, so I've seen it a handful of times, but what I saw this weekend was the most spectacular yet. The dinoflagellates emit a bright aqua blue light when they're disturbed, so the crests of incoming waves flash blue. The glowing starts as a point, and then blooms across the whole wave in a flash. Gorgeous.

On Friday night, Ken and I stopped at the beach on our way home from the fair, and stayed for perhaps half an hour to watch the waves. It was cloudy, a bit pinkish with city skyglow but at least the moonlight was blocked. The waves were stunning, electric blue as bright as Ken's indiglo watch face. I waded in and filled a water bottle to take home; later, when we turned the lights out and shook it, it nearly lit the room (though only for the first instant it was being shaken). With that small a source, the light was more clear to yellowish than blue, but it was still spectacular. What I liked best was that after I'd shake the bottle and put it back down, individual critters would keep flashing for a moment, here and there, like twinkling stars. The dinoflagellates themselves are invisible to the eye -- I've read that the little light specks are a hundred times the size of the creatures making them. I got up a few times during the night, just to tap the bottle gently and get a little flare of light, then watch those flickering stars slowly dying back down into darkness. It's like having a galaxy in a jar.

On Saturday night, after we did a local night cache (more on that in another entry), we went back to the beach with my camera.

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