Thursday, January 21, 2010

Saudi Arabia: Parting the Waters of the Red Sea

Dr. Randi Rotjan, Saudi Arabia Expedition

For most of us, the Red Sea probably conjures a biblical image, if any image at all comes to mind. After all, how many of us have had the privilege of spending any time on or in this relatively tiny stretch of ocean?

Well, time to part the waters and reveal the mysteries that lie beneath. Diving the Red Sea as a scientist is a religious experience of sorts. It's pretty magical down here.

photo: R. Rotjan

To start with, it's beautiful. Relatively calm seas (despite our one day with 40+kt winds and rain... in the middle of a desert) mean clear waters with wonderful light penetration to the depths. These waters are teeming with Anthia spp. fishes, little damsels, clownfish, groupers, turtles, manta rays, dolphins... and of course, corals!!

photos: R. Rotjan

For me, the corals are always the star of the show. One of the most incredible coral experiences I've had here is my introduction to Xenia and Heteroxenia spp. soft corals that actually move (see the underwater movie posted below). Corals are animals that behave like plants and produce a hard calcareous skeleton. As a colleague of mine like to say, they are sea monsters: animal, vegetable and mineral all rolled into one. Corals are (usually) colonial, and have many polyps on a colony. Each polyp is a mouth (think of each polyp as an anemone--same idea, and corals and anemones are closely related). Many corals extend their polyps at night to feed, and keep them retracted during the day. But, these intriguing soft corals feed all day, pulsating to gather plankton and particulate matter from the water column wherever available. In other words, Xenia and Heteroxenia spp. showcase the animal side of corals--they visibly behave!

Speaking of animals, they are everywhere! In contrast to other reefs in the world that host a diverse and abundant flora, the Red Sea is all fauna. The benthos here is overwhelmingly invertebrate, which is stunning. But, how can I talk about animals without mentioning the fishes? Onboard, we've been studying parrotfishes, butterflyfishes, snappers, clownfish, surgeonfishes, pufferfishes and damselfishes, which is a very fishy cruise by my standards. This research agenda has kept us fish-focused for almost all of our science.

photos: M. Noble

However, we've also stolen a glance at some non-research related animal while we've been here--and we've avoided injury, too. Yup, there are lots of toxic animals here. Lionfish, scorpionfish, jellies--we've seen 'em all.

photos: R. Rotjan

The only person who has been stung so far is me. I got a small puncture wound by a crown-of-thorns seastar (shown below) because I was trying to pick it up to see what it was eating (I study organisms that eat coral, and this seastar is the ultimate corallivore). Yup, just another part of being in the water.

photo: R. Rotjan

We've also seen some big organisms--silky sharks, dolphins, manta rays, reef sharks, turtles, spotted eagle rays, coral groupers, giant bumpheaded parrotfish, tuna, and Spanish mackerel ... but they have been rare. In most parts of the world, these large organisms have been overfished, so it's comforting to see them here in the Red Sea.

photos: R. Rotjan

As for me, it's time to strap on my tank and literally part the waters again. There's more science to do, more critters to see, more questions to answer. All in order to do my part ... for the waters.

photos: R. Rotjan


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