I recently (like two weeks ago) stated surfing and ended up swallowing a lot of "red tide" water... not that it will keep me from the surf, is it very harmful? I'm fine today with the exception of a few battle wounds and a sore throat/runny nose. Is that from the red tide stuff? And what's with the bioluminescence... the green, glowy amoeba things? How does that work?
-- Aimee, the net
If the only thing you'd swallowed was red tide critters, you'd be okey-dokey. This particular plankton (Lingulodinium polyedrum) is not toxic to humans and is suitable for swallowing, though not all of them are. And red tides can be deadly to fish and shellfish, and those infected edibles can in turn make you sick. But your gunky nose and throat sounds like typical Surfer's Crud, caused by other stuff you ingested with the planktoni-- human pollution from runoff into the in-shore waters. Anybody who's been surfing for a while will likely tell you they're sick more these days than they've ever been. Will that keep you out of the water? No, didn't think so.
The green glowy things are the same Lingulodinium. When they're peacefully spiraling along through the ocean, propeiled by their little whip tails, no light. If something like a surf board cuts through the group and causes a thousand-plankton pileup, they get all agitated and emit a greenish light. A chemical change inside the organisms disrupts electron paths and eventually photons are released. Why? Gee. Hard to figure a motive for a one-celled organism. Let's just say it has something to do with food, sex, or self-defense-- universal motivators, no matter how many cells you have.