The purpose of diving at Pulau Tenggol at this time of year is the chance to see whale sharks (the world's largest fish). Although they had seen whale sharks in the area during the previous week and we worked pretty hard to find one, we were not fortunate enough to see the big guys this trip. Luckily, there was plenty of other stuff to see underwater.
Going Diving
Gearing up.
Heading to the boat
The Diving
Coral Bleaching
Unfortnunately, the most obvious thing to me about the diving at Tenggol was the massive amount of coral bleaching that had occured. I had heard that bleaching was a problem on the east coast dive sites, but I didn't know how bad things were until I saw it for myself.
What is coral bleaching? To understand this you need to know just a little bit of biology. Corals are an amazing symbiosis of two organisms, and animal and a plant. the animals are from the Phylum Cnidaria (also contains the jelly fish). Each individual Cnidarian polyp is quite small, but thousand and thousands of individual polyps live together to form large corals. The corals secrete calcium carbonate to make the exoskeleton that over time builds up to form the coral reef. The coral polyps feed by filtering small particles and organisms out of the water. Living inside of the coral polyps are little photosynthetic algae known as zoozanthellae. The coral polyps and zoozanthellae live together in a mutualistic relationship; the coral polyps benefit because they get energy from the algae and the algae benefit because the polyp provides a safe place to live and also supplies other needed resources. Coral polyps are colorless, so corals are naturally colorless (white). It is the zoozanthellae that provide color to the corals.
When corals are stressed by pollution, high temperatures, sedimentation etc., then the mutualism between the polyps and the zooxanthellae breaks down and the algae leave the polyps. Without the zooxanthellae living inside them the corals now appear white (coral bleaching). The coral polyps are still alive, but without the energy they gained from the symbiotic algae they are not able to grow as well. In some cases, the corals will eventually regain their zooxanthellae and things pretty much return to normal. In other cases, the corals do not regain their zooxanthellae and the coral eventually dies. I hope the latter scenario does not occur in Malaysia.
If you want to learn more about corals and coral bleaching check out a presentation I made for a class I taught last fall (OK, this presentation has 123 slides in it, but it is pure Dr. McG brilliance, so I know that you will want to savor every slide). This presentation talks about corals and discusses some of the theories about the causes of coral bleaching.
http://www.slideshare.net/secret/MXAjnaF502X8PL
You can also look at an Environment in Focus presentation on coral bleaching from the Encyclopedia of Earth.
http://www.earthportal.org/?p=1019
Here is a link to an article in today's Star Newspaper about coral bleaching in Malaysia entitled "Corals on the brink"
http://thestar.com.my/news/story.asp?file=/2010/7/29/nation/6746036&sec=nation
Still Lots of Cool Things to See
(all of these underwater photos were taken by Yati Ahmad)
Nudibranchs
Gorgonians
Stingray
Anemone fish
Dog-faced pufferfish
Shrimp
Enjoying The Surface Interval
This photo is taken from almost the exact spot where the sea turtle dug its second nest later on that night.
Ready to Dive Again Tomorrow
Anyone who has ever been diving with me should be able to spot my gear!
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