Mega Marine Survey Day 2: Pulau Ubin

I've just returned from my first field session with the Northern Expedition of the Comprehensive Marine Biodiversity Survey; Ria has a post on the preparations that took place before the field trips commenced today.



Our base of operations is at Outward Bound Singapore (OBS), on the western side of Pulau Ubin.

Saturday Seringat-Kias

A small group headed out to visit Lazarus Island on one of the last early morning low tides of the year. While the rest headed towards the rocky shores of Lazarus Island, Kok Sheng and I decided to explore a lagoon located in the north of Seringat-Kias; James and I had previously checked out this area in April 2010. On that occasion, we visited that lagoon during the day, and it was raining, so we might have missed out on a lot of the marine life that lived in that lagoon. Hopefully, we would find a more interesting variety of critters this morning.

Sharing Singapore with visiting scientists

Several marine scientists from all over the Asia-Pacific are in town for a workshop on marine biodiversity in the South China Sea. I was able to spend a day helping out with the Raffles Museum of Biodiversity Research (RMBR) as a guide, sharing about Singapore's natural heritage to specialists from the region. (Edit: Mei Lin was a participant as well, and shares more about the workshop in this post)

World Oceans Day @ Tanah Merah

Yesterday was World Oceans Day, and in recognition of this day in which we are supposed to "celebrate and honour the body of water which links us all, for what it provides humans and what it represents", the International Coastal Cleanup Singapore (ICCS) team conducted cleanups of 2 stretches of coastline. I had signed up for Tanah Merah Site 7, the same place I had volunteered for earlier in April as part of a series of year-round coastal cleanup efforts. I have visited this shore infrequently every year, and it really is gratifying to see how the efforts of small groups of individuals have truly helped make a difference in reducing the amount of trash accumulating here.

Earth Day Coastal Cleanup @ Tanah Merah

For those of us who visit and explore the shores of Singapore to document the marine life that can be found on our coasts, Tanah Merah stands out as a unique and special place. Although the original shore here is long gone due to land reclamation, a rich community of marine organisms has managed to colonise and reestablish itself. We find habitats as diverse as rocky shores, seagrass beds, sandy beaches, coastal forests, and even a coral reef on the outer edge of the seawall.


(Photo by Ria)

Unfortunately, this shore, despite its beauty and diversity, suffers from pollution. Much of the marine life is slowly recovering from the devastation of the oil spill that struck 2 years ago, although some crude oil still lingers in the environment. Another insidious threat comes from the vast quantities of garbage that wash up and get trapped behind the seawall. Because this area is not under the purview of the armies of cleaners that work tirelessly every morning to remove litter and other trash from our public beaches, the rubbish simply accumulates, forming massive piles of plastic, broken glass, and other debris.


Litter on Tanah Merah shore, July 2011;
(Photo by Ria)


Dig deep enough, and you'll find out where much of the oil has gone, April 2012;
(Photo by Ria)

In response, the International Coastal Cleanup Singapore (ICCS) team has decided to conduct a series of year-round cleanups on this shore.



And so, keen to do my part on a shore that I am personally very fond of, I signed up for the latest session, which was held on the morning of 28th April.

Year of the Dragon: Dragon Slugs

Beting Bronok;
(Photo by Ria)

Yes, even soft, spineless creatures can be named after dragons.

Giant jellyfish seen at Pasir Ris

Monday Morgue: 21st February 2011

Mass of button zoanthids (Zoanthus sp.)
Pulau Ubin, 18th October 2008

Wild Fact Sheets
Advanced Aquarist
WetWebMedia.com
Sea Mat: An Ocean Of Color For The Aquarium

Raffles Museum Treasures: Blue lion's mane jellyfish

Blue lion's mane jellyfish (Cyanea lamarcki)
Collected from West Coast, May 1987
Visitor

The Marine Life Information Network
British Marine Life Study Society: British Jellyfish
British Marine Life


(Photo by Danygraig)

Raffles Museum Treasures: Stinging hydroid

Stinging hydroid (Gymnangium hians)
Collected from Jurong
Native to Singapore

Wild Fact Sheets


(Photo by Ria)

Raffles Museum Treasures: Cauliflower coral

Cauliflower coral (Pocillopora damicornis)
Collected from Singapore Straits
Native to Singapore

Wild Fact Sheets
IUCN Red List
ARKive
Reefs.org


(Photo by KaylaS)

Raffles Museum Treasures: Torch coral

Torch coral (Euphyllia glaberescens)
Collected from Pulau Seringat reef flat, December 1997
Native to Singapore

Wild Fact Sheets
IUCN Red List
ARKive
Reefs.org


(Photo by Ria)

Raffles Museum Treasures: Flowery disc coral

Flowery disc coral (Turbinaria peltata)
Collected from Cyrene Reefs, April 1984
Native to Singapore

Wild Fact Sheets
IUCN Red List
ARKive
Atypical morphology of Turbinaria peltata from a Singapore non-reefal environment


(Photo by RemyOmar)

Raffles Museum Treasures: Lettuce coral

Lettuce coral (Pavona cactus)
Collected from reef off Pulau Hantu, October 1979
Native to Singapore

Wild Fact Sheets
IUCN Red List
ARKive
Reefs.org


(Photo by Boogies with Fish)

Raffles Museum Treasures: Fire coral

Fire coral (Millepora sp.)
Collected from Pulau Seringat Besar reef flat, April 1998
Native to Singapore

ARKive
The Right Blue
Wet Web Media
Reefs.org


(Photo by Razvan Marescu)

Raffles Museum Treasures: Cabbage coral

Cabbage coral (Trachyphyllia geoffroyi)
Collected from reef off Sentosa, November 1979
Native to Singapore

Wild Fact Sheets
IUCN Red List
ARKive
Wet Web Media


(Photo by Ria)

Raffles Museum Treasures: Zebra coral

Zebra coral (Oulastrea crispata)
Native to Singapore

Wild Fact Sheets


(Photo by Jeff)

Raffles Museum Treasures: Staghorn coral

Staghorn coral (Acropora valida)
Collected from Cyrene Reefs, August 1992
Native to Singapore

Wild Fact Sheets
IUCN Red List
ARKive


(Photo by Ria)

Raffles Museum Treasures: Blue coral

Blue coral (Heliopora coerulea)
Collected from Pulau Seringat Besar reef flat, December 1997
Native to Singapore

Wild Fact Sheets
IUCN Red List
IUCN Species of the Day
ARKive


(Photo by Ria)

Special Sentosa

Today was one of my last low tide trips for the year, and because I had not explored the shores of Sentosa for almost 6 months, I decided to check out Tanjung Rimau, a place with a great deal of sentimental value for me.

This time was a little different though, since I was joined by my good friend Valerie, who also happens to be this year's winner for the Miss Earth Singapore pageant.


Here's a photo of Valerie on her virgin shore trip.

We made our way down to the shore at dusk, and as we waited for the tide to recede, we wandered amongst the rocks, looking at the various snails that lived on the high shore.


Such as these spotted top shells (Trochus maculatus).


And these lightning dove snails (Pictocolumbella ocellata). Other snails that we looked at included toothed top shell (Monodonta labio), chameleon nerite (Nerita chamaeleon), spiny drill (Thais bitubercularis), dwarf turban snail (Turbo bruneus), and ribbed turban snail (Turbo intercostalis).


We also spotted several big pimply onch slugs (F. Onchidiidae) crawling about on the rocks.

A while later, we ventured into the shallows, where we encountered large numbers of crabs.


Blue swimming crabs (Thalamita danae) and blue-spined swimming crabs (Thalamita prymna) were extremely common, but as usual, they were so shy and skittish that most of them refused to stay still long enough to be photographed. This particular crab was stranded in a small pool.


Strangely enough, we saw only a single common hairy crab (Pilumnus vespertilio). Either we were not alert enough to see more, or they were all in hiding.

As you can see from the photo, the common hairy crab was perched near a mass of sea mat zoanthids (Palythoa tuberculosa). Was it about to feed on them? The common hairy crab is a generalist omnivore, and is known to feed on zoanthids, which apparently render the crab mildly poisonous and unappetising to potential predators.


A crab that we kept seeing today was the red egg crab (Atergatis integerrimus). We saw at least 6 of them! This species is highly poisonous.


Somewhat less common was the floral egg crab (Atergatis floridus); we found 2 over the course of the visit. Like the red egg crab, it too is highly poisonous.


A very special crab find for me was this red-eyed reef crab (Eriphia ferox). If I'm not wrong, this is my first ever sighting of this species.

Other crustaceans that we encountered included plenty of sea slaters (Ligia sp.) on the high shore, as well as glass shrimp (Palaeomon sp.) and red-nose shrimp (Periclemenes sp.) in the shallows. Of course, it was impossible to miss the loud clicking of the snapping shrimps (F. Alpheidae), even though they remained hidden in their burrows.


These shores are also very good for spotting two-spot reef octopus (F. Octopodidae). Both Valerie and I were extremely thrilled when we encountered a pair that seemed to be mating! Another first sighting for me.


In male cephalopods, one of the arms, known as the hectocotylus, is modified to storm sperm packets, which he then transfers to the female by inserting this arm into her mantle cavity. You can see how the male in this photo is literally being dragged all over the place as the female moves around.


Later on, we saw a second mating pair of octopus. The smaller male spent quite a bit of time riding on top of the female's head. If octopus could talk, I can imagine the female exclaiming, "Get off! I can't see!"


Another special find was this giant top shell (Tectus niloticus).

We didn't have much luck finding black long sea cucumber (Holothuria leucospilota), and only managed to find a small one hiding beneath a rock.


We were however lucky enough to find another long (and disgusting) creature hiding amongst the coral rubble, the giant reef worm (Eunice aphroditois). I saw these worms on 3 separate occasions, but only managed to take 1 photo of the face. Despite their size, these worms are extremely shy and will immediately dart back into their burrows upon the slightest disturbance.


We spotted quite a lot of fish such as young mullet (F. Mugilidae) and tropical silversides (Atherinomorphus duodecimalis), but these usually swam off instantly. This false scorpionfish (Centrogenys vaigiensis) stayed still long enough for us to snap a few shots.


We didn't really have much time to walk around looking at corals, but we did find quite a few colonies of soft corals, such as this pinwheel leathery coral (F. Alcyoniidae).


As well as several omelette leathery corals (F. Alcyoniidae).


I think this is a big o-ring favid coral (F. Faviidae).


The tide rose, but just before we went back to wash up, we spent some time looking at the land hermit crabs (Coenobita cavipes) crawling about on the seawall.


Valerie had to go off first, and as I was washing my booties, I came upon a few of these terrestrial snails.

I decided to spend just a bit of time exploring one of the islets off Siloso Beach, which are another very special place for me. The tide was steadily rising, and I was too lazy to dig out my net and container from my bag, but I could still walk around in the shallows and see what I could find.


As usual, the bridge is festooned with all sorts of soft corals, zoanthids, sponges, ascidians, bivalves, and other sessile organisms.


There were plenty of fish in the lagoons, the usual cast of characters that I'd seen on virtually all of my previous visits; tropical silverside, larger adult mullet, sand whiting (F. Sillaginidae), Kops' glass perchlet (Ambassis kopsii), all sorts of halfbeaks (F. Hemirhamphidae), orbicular cardinalfish (Sphaeraemia orbicularis), and shadow goby (Acentrogobius nebulosus). I caught a glimpse of a medium-sized striped eeltail catfish (Plotosus lineatus) as it swam around close to the surface, then darted out of sight.


However, this was the first time I had seen banded needlefish (Strongylura leiura) in these lagoons.


Another fascinating find was this peacock sole (Pardachirus pavoninus) which I spotted from the bridge, hiding on the sand at Siloso Beach itself. I tried to get closer to take more photos, but it slipped beneath the bridge. I wish I had taken out my net and container, then I might have been able to ambush it and take a bunch of clear and decent (if somewhat unnatural-looking) shots. So we'll have to content ourselves with this horrible picture.


There were plenty of crustaceans here as well, such as this spotted moon crabs. There were also quite a few blue-spined swimming crabs, flower crabs (Portunus pelagicus), and blue-tailed prawns (F. Penaeidae).


Purple climber crabs (Metopograpsus sp.) were common on the rocks and the bridge.


There were quite a few pearl conch (Laevistrombus turturella) and black-lipped conch (Canarium urceus) half-buried in the silt. Other snails seen included spiral melongena (Pugilina cochlidium), as well as the usual hordes of zoned horn snails (Batillaria zonalis).


Here was a very surprising and special find, a live wandering cowrie (Cypraea errones).


It was quite a nice coincidence, as I had just learnt that this species has a dark spot close to the front end of the shell, unlike the very similar ovum cowrie (Cypraea ovum).


It is always nice to find the common sea stars (Archaster typicus). I was unable to find the colony of adults that I'd found on previous occasions; I suspect that the entire group was already well submerged by the rising tide by the time I arrived. However, I did find a small group of juveniles, which is a good sign. This either means that this population of sea stars is reproducing, or that larvae are drifting in from elsewhere and settling on this shore.


Just before I was about to call it a night and head for home, I found this tiny polyclad flatworm (Polycladida). I have no idea what it is, although my hunch is that it is a species of Pseudobiceros.

Is this another unknown species? It reminds me of the large unidentified flatworm I had found at Siloso Beach earlier this year, just that it lacks the orange margin possessed by the latter. What other secrets lay hidden in the murky depths of these lagoons?

It was getting late, so I headed back towards the Beach Station to take the bus.


Much of Siloso Beach is being set up for ZoukOut 2009, which takes place next Saturday. Hopefully, the marine life will not be too badly affected. But then again, the creatures living in this lagoon must be very tough indeed. They already receive a daily auditory and visual assault from Café del Mar and Songs of the Sea, have survived the annual ZoukOut and Siloso Beach Party, and it seems that they have survived the construction of the MegaZip, in addition to 2 new clubs along the beach, Azzura and Wave House Sentosa.


It was nice to walk past the pond and see this sign. Now I know why the pond exists in the first place.


All around the pond, I could hear the calls of common Asian toad (Duttaphrynus melanostictus) and dark-sided chorus frog (Microhyla heymonsi), although they remained out of sight.


This millipede wasn't so shy though.

I didn't really get to explore the shores to my heart's content, but I was definitely very thrilled to see that these familiar shores at Sentosa still appeared to be doing quite well. No matter how many times I visit, it seems that there is always something new and surprising.

Such is the magic and beauty of the shores, that compels one to visit repeatedly, not quite knowing what to expect. You can never visit a place too often.