Saturday, September 12, 2009

There's always room for jellyfish

Last weekend, we heard of jellyfish on Daytona's beaches. On Labor Day, Margie reported: The jellyfish that invaded Daytona last week seem to have found their way down here to Cocoa Beach. There were a lot of moon jellies washed up. I didn't see anything that looked like a box jelly, but I didn't poke anything unidentified with my foot either. Those things are nasty. On the other hand, there were people in the water and I heard no screaming, as was the case the last time we had box jellies out there. I saw quite a few blue buttons along with the jellyfish, and one sea pansy. (Margie's photo shows a moon jellyfish.)

Apparently the winds were blowing the critters south - on Wednesday, Ann sent photos from her early morning sea turtle nest monitoring walk on Satellite Beach - love how the sunrise colors are reflected by this in the moon jellyfish and the sand.

So I got to wondering how long a beached jellyfish will live, can they survive long enough to wash back out to sea in the next tide, what happens if you step on a dead one, etc. etc. etc. I put those questions out to friends and beach experts Blair and Dawn Witherington, and of course got a an excellent explanation from Blair, as follows:
Medusae (bell-and-tentacle form of jellyfish) are pretty fragile animals. When bad luck brings them to a beach, they are done for. However, their nematocysts (stinging cells) can fire after death. This is why one can still receive a sting from a jelly blob on the beach. Few should be troubled by this prospect. Foot bottoms are thick enough to defend us from this assault, and only a few of our local jellies have a significantly painful sting. One of these was in your photos, a sea nettle, identified by reddish-brown radiating rays. Might want to step around that one. (Shown below in Ann's photo)

Blair goes on to say: Not many animals eat jellyfish. The short list includes leatherback sea turtles, molas (ocean sunfish), some sea birds, and humans. Yes, the group of jellyfish containing the cannonball jelly is edible. I’ve tried it. Not bad with the right seasoning. Animals that specialize on a diet of jelly (like leatherbacks) have to eat a lot of them. Most jellyfish are about 95% water. By contrast, we are about 65% water.
Blair and Dawn's book, Florida's Living Beaches - a Guide for the Curious Beachcomber, has a good section on jellyfish. If you don't have their book (you should), you'll be able to get an autographed copy at the Sea-Bean Symposium, October16 and 17 (see Reference Link below for symposium information).
David McRee has an excellent post about jellyfish on his BeachHunter site (see Reference Links). David will be at the Sea-Bean Symposium with his book, Florida Beaches - Finding Your Paradise on the Lower Gulf Coast.
Blair and Dawn are experts on the "technical aspects" of Florida's beaches (critter identification, dunes, tides, etc), and David is a "destination" expert (lodging, can I bring my dog, what is the most romantic beach, where do I eat, etc.), so the symposium will offer a great opportunity to pick some excellent minds about all aspects of Florida beaches.
As always, thanks to Margie, Ann, Blair, Dawn, and David for sharing their expertise and photos. These are folks that are on the beach daily - it is "home" to them, and they see nuances and events that escape the casual beachgoer (like me). That's one of the things that makes the Sea-Bean Symposium such a neat experience - the presenters and exhibiters love what they do and what they study, and they get great delight in exchanging ideas and knowledge with others. It's a mellow time - make plans to attend.
Reference Links:
BeachHunter (David McRee's post on jellyfish)
Blog the Beach (David's post about jellyfish sting neutralizing gel)
Sea-Bean Site (Paul has updated the official sea-bean site with lots of symposium information)


Caroline said...

What a neat vicarious "beach walk"!
I love the thought of finding moon jellies, blue buttons and sea pansies on a walk. What ever they are, they are more interesting sounding than South Dakota grasshoppers at the moment! They are eating my flowers, then the turkeys are eating them, so I guess that is poetic justice.

Cactus Jack Splash said...

Poor little stinging critters, sad to die stranded on the sand.
Glad you warned about the brown one, if I was ever on the beach and saw that one I probably would have tried picking it up thinking it was a sea bean.