16 June 2010

Bleaching at Cyrene

Today, we are very lucky to have a most sporting team from URA and NParks visit Cyrene Reef!
Here's some of the happy team, glad to have made the amphibious landing safely.

As soon as we land, we encounter Cake sand dollars (Arachnoides placenta) and Common sea stars (Archaster typicus) in the clean sand that forms a bar down the centre of this huge submerged reef. We are also fascinated by the very many large Fan shell clams (Family Pinnidae) that dot the sand.
When we hit the coral rubble area, the team shares a baby Cushion star (Culcita noveaguineae) that Chay Hoon has found! As we head out to the reef, alas, we notice the shore is dotted with many white and flourescent yellow soft corals, and a few white hard corals.
Under the gloomy sky, the bright white bleached corals are very obvious.
Among the bleached corals were many Flowery disk corals (Turbinaria sp.) and Cauliflower corals (Pocillopora sp.). The most obviously bleached were the many flowery soft corals (Family Nephtheidae) and the leathery soft corals (Family Alcyoniidae) which can take many different shapes that resemble fried eggs to surgical gloves.
Many of the leathery soft corals were 'peeling' with thin layers of their skin peeling off.
Here's a closer look at a 'peeling' leathery soft coral. I'm not really sure what this means.
Another view of bleaching soft and hard corals with Pulau Bukom on the horizon. Corals, hard and soft, as well as other related animals turn white when they lose the symbiotic algae that usually live within their bodies and produce nutrients through photosynthesis which is shared with the host. The algae also give the host their colours. When the animals are stressed, they may lose their algae and thus turn colourless, showing the white skeleton or common tissue.
Only two weeks ago on our last visit to Cyrene, the hard and soft corals were alright (see photo below). Coral bleaching has been happening around the world since May, hitting reefs in Maldives, Thailand, Malaysia and Australia. These places are experiencing the worst bleaching in many years. This global bleaching event is due to the higher than usual sea surface temperatures. More about coral bleaching on Bleach Watch Singapore with the prognosis for reefs in our part of the world.
Fortunately, unlike some of the other shores we recently visited, only a few of the big hard corals were completely white.
Here's some hard corals that haven't turned completely white. A Flowery disk coral (Turbinaria sp.) that, however, doesn't look too happy. And a brown Pore coral (Porites sp.) that seems fine.
The hard corals on Cyrene can be quite large! This one still looks unbleached.
Many of the big hard coral colonies were still brown, which is their usual colour.
Despite the bleaching, the reefs here are still very much alive. Marcus finds us a Jorunna nudibranch (Jorunna funebris)! It's quite commonly seen on our reefs. Singapore has lots of fascinating nudibranchs in all kinds of shapes and colours!
Wei Ling has found a cute hairy crab (Pilumnus sp.)! After getting the search image, the rest of us start to see more of this common creature of our reefs.
No matter how many times we visit Cyrene, we always encounter things we have not seen before. This is a strange blob that I've not seen before. Possibly a sea anemone? Chay Hoon also found a special sea star - see Kok Sheng's blog about it. The presence of so much interesting marine life is one reason why Cyrene is a great destination for world-class scientists who visit Singapore.
Wow, my first time seeing a heart urchin on Cyrene. Although it is very dead, it is only recently dead as its spines are still stuck on the skeleton. It looks like an Oval maretia heart urchin (Marieta ovata). If so, it will be the first we've seen on our Southern shores! Indeed, in many ways, Cyrene is like the Chek Jawa of the South, sharing many creatures from the more famous northern shore. Heart urchins are related to sea stars (see the five-part star-shaped thing?) and are burrowing creatures that are seldom seen alive above ground.
More good news! Tsen Yang has found a Fluted giant clam (Tridacna squamosa)! This is hopefully the same one that I saw in Oct 08 (below) that we since have failed to relocate despite many trips. Wonderful!
Besides the reefs, Cyrene is special because it has one of the best seagrass meadows in Singapore. Wei Ling kindly briefs the group about Cyrene's seagrasses. She is one of the coordinators of TeamSeagrass, a team of volunteers monitoring seagrasses in various locations including Cyrene. From the work of TeamSeagrass, it seems Cyrene has the most variety of seagrasses in good health in Singapore. Including some rare ones like the Noodle seagrass (Syringodium isoetifolium). Meanwhile, as the weather starts to really turn nasty, I hurry off to find where the Knobbly sea stars are hiding.
I looked for them where they were seen on our last trip. And no Knobblies! Panic! Fortunately, Jim found out where they were all hiding! Yay! Thank you Jim!
Jim has found lots and lots of the Knobbly sea stars (Protoreaster nodosus) that Cyrene is so famous for. Big ones, small ones and really tiny ones. Cyrene not only has probably the largest population of these sea stars, but also the most number of baby Knobbly sea stars in Singapore! On other shores, while we may see large Knobblies, we don't see small ones. Or only a few small ones. The presence of so many babies led the Star Trackers, who are studying the Knobblies on Cyrene as well as our other shores, to believe that Cyrene may be the only sustainable population of Knobblies left in Singapore.
Gianormous black clouds seriously gather above us and we sense rumbles building up in the sky. It's time to go leave!! Sadly, Cyrene is too huge to see everything during one brief low tide window.
It's tricky doing an amphibious trip with high waves and high wind.
Fortunately, as usual, Jumari gets us all back safely to the big boat.
The trip home was rough as the weather really built up and we got hit by big waves. Fortunately, no one was hurt as the boat tossed about. It was only later that I heard that the fierce downpour caused flash floods on the mainland! Wow, we are very lucky that the weather held long enough for us to have a quick look at Cyrene.

Today, I am happy to launch the new "I've Been to Cyrene" badge, mainly because I've run out of stocks of the old badge. Mei Lin says it's the 'pre-dawn' version! Indeed, this badge features one part of the 'industrial triangle' around Cyrene: our world-class container terminals and the city skyline during our dawn trip a few weeks ago. With the spectacular Pentaceraster sea star (Pentaceraster mammilatus) that was first recorded for Singapore from Cyrene Reef! It also features Cyrene Reef Exposed! the new blog focusing only on Cyrene.
And I'm glad that everyone who started on the trip got a badge. Only survivors get one!

I had a great time thanks to a very obliging and sporting team. Who put up with my droll and lame jokes and found many interesting things and asked many thoughtful questions. I hope they had a memorable experience on Cyrene, as many others who have been to Cyrene.

More good news: Alex and Jumari have agreed to take us to Cyrene at night! So we are looking forward to visiting our most favourite reef when things are the liveliest!

More about Cyrene Reef on Cyrene Reef Exposed!

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