Tuesday, June 24, 2008

Discover the not-so-oftenly seen part of Singapore

Sixty Fourth Discovery Posting:

Today, as I was doing the job of hunter seeking at St. John's island, I was thinking about how to blog about this trip and it came to me that I have always been focusing more on the flora and fauna of the places I've been visiting rather than of things from a larger angle. Thus came the idea of this blog entry.

Why do I like to visit Singapore’s shores? Is it special?
"Singapore's shores are easy to get to! Uniquely Singapore! Where else in the world can a visitor quickly go from a high-level business meeting at a world class hotel to visit a living reef or mangrove? In under half an hour? The reefs of the Southern Islands are just 15 minutes away from the mainland by fast boat." (extract from Wildfilm's blog entry)

Look (picture below), this was taken at St John's Island this morning without me using any optical zoom with my camera, so you can see how near you can be from our natural shores!
Now let's turn our attention to the Great Barrier Reef a while for some figures. Studies has concluded that there are about 400 species of hard corals there. You might wonder why am I bringing up the Great Barrier Reef when knowing that the amount of reef area we have in Singapore is not even 0.1% compared to the Great Barrier Reef.

Well. Below's a figure which might capture your attention.

"The reefs in Singapore harbour close to 200 species of hard corals, which given the size of the reefs and conditions present here, compare favourably with coral species richness in the more extensive reefs of the region" (extract from the Coral Reefs of Singapore website, Reef Ecology Study Team, NUS)

Some photos of corals from St. John's Island below

Now, you might be thinking, Wow! Two hundred species compared to four hundred! This should be make known to all (the idea behind this discovery blog entry)! One might even say this is a neglected heritage of Singapore, as written by Liana recently on the Straits Times.

Click here to read the article online on the wildsingapore's news blog.

So now, you might wonder,
Can I experience Singapore’s marine heritage without much hassle?
In fact, the answer to this question is a YES!
“No need to swim, no need to dive! Many volunteer groups provide guided walks on boardwalks and low tide walks for ordinary people. An ideal trip for the family, bring grandma and the little kids!. " (extract from Wildfilm's blog entry)

Of course, do bear in mind that you will get your feet wet for low-tide walks. Well. But isn't that part of the fun of visiting a shore? =)

What can I see at these place? Just corals?
Well, not just corals. For this part, i would say pictures are worth a thousand words =)
Below are a peek of some things which I saw during my trips to St. John recently...

A flatworm (picture below)
Brittle star (picture below)A sea snail with a beautiful shell (picture below).And if you read my other discovery blog entries, you will discover many other things one can find on our shores.

a) Free photos of flora and fauna one can find on Singapore's shores. Download them to be your desktop picture. Click here to get them!
b) Click here to find out more about our reefs on the blog for International Year of the Reefs 2008!

By now, you might be very tempted to pay a visit to our shores, so here's some information (below) to help you to discover our wonderful shores!

Raffles Museum of Biodiversity Research (NUS)
Conducts guided walks at Pulau Semakau and workshops for schools on our shores.

Chek Jawa (NParks)
Conducts guided walks on the shores of Chek Jawa.

Blue Water Volunteers
Conducts guided walks at Kusu Island, underwater reef surveys and guided dives at Singapore’s reefs, as well as outreach through talks and exhibitions.

TeamSeagrass (with NParks)
Monitors the seagrass meadows at 6 locations as well as outreach through talks and exhibitions.

Naked Hermit Crabs
Conducts guided walks at the Chek Jawa boardwalk every month, and family walks at Sentosa’s natural shores during the school holidays as well as outreach through talks and exhibitions.

Sungei Buloh Wetland Reserve (NParks) about 40 volunteers
Conducts guided walks at the Reserve

Hantu Bloggers
Conducts guided dives at Pulau Hantu as well as outreach through talks and exhibitions.

Sunday, June 22, 2008

Semakau Inter-Tidal walk on 21 June 2008

Sixty Third Discovery Posting:

Besides stunning sunsets, sometimes if we go to Semakau early enough, we get to watch the wonderful sunrise too (pictures below).

In this discovery posting, I'm going to write about a particular thing which might not get as much attention from visitors as compared to the seastars and nudibranches. Some reasons why this is so might be because it isn't colourful, it doesn't move around, one can almost certainly see it every time when they visit Semakau's inter-tidal area.

So what am I going to write about? Well, seagrasses (picture below)!
Discovery Note (Seagrasses in a glance):
1. They are called seagrasses because like grasses, they have roots, leaves and rhizomes (horizontal underground stems that form extensive networks below the surface).
2. But they are not true grasses and actually they are more closely related to water lilies and terrestrial plants (plants which live on the ground) such as lilies.
3. Since they are named, 'seagrasses', so it isn't strange that they can live underwater.
4. They are also the only marine flowering plants.

Discovery Note (More detailed information about seagrasses):
1. Seagrasses are commonly found on tidal mudflats in estuaries, on shallow sandy areas close to the coast, in coral reef lagoons and around sand cays.
2. They can also grow up to depths of more than 10 meters but this is limited by water clarity because they require light for photosynthesis (The process by which plants use light to 'make food' from carbon dioxide and water).
3. Seagrass can reproduce through sexual or asexual methods.
4. In sexual reproduction, the plants produce flowers and transfer pollen from the male flower to the ovary of the female flower. Most seagrass species produce flowers of a single sex on each individual, so there are separate male and female plants.
5. For asexual (or vegetative) reproduction. New ‘plants’ arise without flowering or setting seed. Seagrasses grow vegetatively by extending and branching their rhizomes in the same way that grass in a lawn grows. This allows significant areas of seagrass meadow to form from only a few

At this point, you might start to see a bit of 'stars' from all this information or even ask, "So what? Why talk about seagrasses?" Here's why...

Discovery Note (The GOOD things about having seagrasses) :
1. They help maintain water clarity by trapping fine sediments and particles with their leaves.
2. They can stabilize the bottom with their roots and rhizomes in much the same way that land grasses retard soil erosion.
3. Seagrasses and the organisms that grow on them are food for many marine animals like the dugong (sea cow) and turtles.
4. Seagrasses which dies and have been broken down into smaller pieces also forms a part of the food chain in a marine ecosystem.
5. They are homes and nursery areas for for a vast variety of organisms including molluscs, crustaceans (prawns, shrimp and crabs) and fishes (both the kind you eat (commercial species) and the kind you like looking at (reef fishes)).
6. And so one can find lots of marine creatures amongst seagrasses if you look carefully...

Here are some of them which we saw during this trip.

A ocellated sea cucumber (picture below)
A synaptid sea cucumber (picture below)
And seahorses also like to hide amongst seagrasses , here's one of them (picture below)Well, we did see many more things in this trip, to find out, you can read about
a) KS's wonderful creation on his first time guiding alone at Semakau
b) RY's pictures of two seahorses
c) ST's galore of pictures
d) SY's first time as a hunter seeker at Semakau

Enjoy! =)

For discoverer's information, there is a team in Singapore whom monitors seagrasses, they are known as 'Team Seagrass', keen to learn more or go out in the field to look at seagrasses. Visit their blog @ http://teamseagrass.blogspot.com/

a) http://www.reef.crc.org.au/publications/brochures/CRC_Reef_seagrass_web.pdf
b) Singapore's Team Seagrass blog

Sunday, June 8, 2008

Semakau Inter-Tidal Walk on 7 June 2008

Sixty Second Discovery Posting:

Back at Semakau again, this time we were guiding a group of students from Jurongville Secondary and 'Octopus ' was the group of people I was guiding.

Side note:
I finally saw dolphins in our waters, actually SY spotted them as we were on the boat towards Semakau, I saw 3 dolphins while others spotted a total of 5! Wow! Too bad none of us managed to get a picture of them in action.

Here are the octopus-es or octopi on the move towards the forest trail which we had to go through before reaching the Inter-tidal area (picture below)
Upon reaching the Inter-tidal area, we headed straight out to escape from the mozzies, as we were literally 'food' for them. =P

After an explanation of the many things one can find if you look closely, seagrass and sponges, we proceed to cross the seagrass lagoon and with the a group photo (picture below).
After crossing the lagoon, we saw the first 'discovery' of the day, the ocellated sea cucumber (picture below).
Discovery Note:
1. Do you know they belong to the same phylum as the sea stars? This family is called echinoderms, or in simple terms, spiny skinned animals.
2. Sea cucumbers has a water vascular system compared to the blood vascular system for us (humans).
3. Therefore they will feel 'stressed' if removed from water, and when that happens, they may eject water, sticky threads or even their internal organs.
4. For this species of sea cucumber, this is said that they may eject their internal organs, and it's not hard to guess that if this goes on for too long, they will eventually die.

And the second 'discovery' is something related to the sea cucumber, the common sea star (picture below).
Discovery Note:
1. Yes, they belong to the same phylum of animals as the sea cucumber, the spiny skinned animals or echinoderms.
2. An interesting thing about some sea stars is that, when they feed, they actually push out their stomachs to engulf and digest food. They might also use their limbs to help engulf their food.
3. Some species take advantage of the great endurance of their water vascular systems to open the shells of molluscs (clams, mussels and the like), and inject their stomachs into the shells. Once the stomach is inserted inside the shell it digests the mollusk in place. Because of this ability to digest food outside of its body, the sea star is able to hunt prey that are much larger than its mouth would otherwise allow (including mollusks, arthropods, and even small fish)

Reference for point 3: http://www.planetarios.com/Handbook-paleozoic/archastertypicusseastars.html

The octopus-es also spotted a number of hairy crabs as we explored the inter-tidal area. Third 'discovery' is one of them(picture below).
Discovery Note:
1. They are NOT the same hairy crab which some people eat.
2. They are actually poisonous due to what they eat, zoanthids or colonial anemones which scientists have found one of the most toxic poison in a type of colonial anemone.

Fourth 'discovery' is a cowrie, something which I have not taken a good photo for some time (picture below).
Discovery Note:
1. They have shells but it is usually covered completely by their mantle.
2. This mantle prevents algae and encrusting animals from settling on their shell.
3. The mantles of cowries have historically been used as currency in several parts of the world, as well as being used, in the past and present, very extensively in jewelry and for other decorative and ceremonial purposes, therefore the fate of over-collection for them.
4. They feed on algae and seaweed.

And for fifth 'discovery', we saw a puffer fish (picture below)!
Discovery note:
1. They are named for their ability to inflate themselves to several times their normal size by swallowing water or air when threatened.
2. They have four large teeth, fused into an upper and lower plate, which are used for crushing the shells of crustaceans and mollusks, their natural prey. They also enjoy the occasional bloodworm
3. The eyes and internal organs of most puffer fish are highly toxic, but nevertheless the meat is considered a delicacy in Japan and Korea.

We were really lucky today, as this is the first time I have seen a seahorse today (picture below)! Sixth 'discovery'.
Discovery Note:
1. Seahorses are poor swimmers, thus they are most likely to be found resting in sea grasses or coral reefs with their prehensile tails wound around a stationary object.
2. They have long snouts, which they use to suck up food, and eyes that can move independently of each other. Seahorses eat small shrimp, tiny fish and plankton.
3. An interesting fact about them is that the male seahorses actually carries the fertilized eggs into its pouch.
4. Depending on the species, a male seahorse can give birth to as many as 2,000 babies at a time and pregnancies last anywhere from 40 to 50 days.

The seventh 'discovery' is a marginated glossodoris nudibranch (picture below).Discovery Note:
1. 'Nudibranch' means 'naked gills'. The name comes from the flower-like gills found on the back of many nudibranchs. These nudibranchs use the gills to breathe.
2. Nudibranchs are related to snails. Little baby nudibranchs are born with shells, but they lose them when they become adults.
3. Most nudibranchs are carnivores, they eat immobile or small, slow-moving prey. Examples are sponges, ascidians, hard corals, soft corals, sea anemones etc.

And Octopus-es also got the chance to meet themselves, an octopus!

Here's another group shot of all Octopus-es at the southern most point of Semakau (picture below).
Thanks everyone for being attentive and fun, you were a great lot! =)

a) Read Tidechaser's blog entry on what his group saw.
b) Check out Manta's blog to see what he found as a hunter seeker.

Friday, June 6, 2008

Sentosa Walk with NHC on 6 June 2008

Sixty Second Discovery Posting:

Today is the first anniversary walk for the Naked Hermit Crabs and we were back at the place where we conducted our first guided walk, the natural shores of Sentosa!

I always enjoyed the view of the natural shore of Sentosa (picture below). Today's tide was also really low that I could see parts of the shore which I've never seen exposed before. Wow!
Anyway, my role was a guide today and two fathers, David and Edwin (if i remembered your names correctly) with their kids (Daniel, John and Madeline) was in my group.

Here are the kids with a 'wave constructed' cave around the area (picture below).
We were really lucky today to see a pair of coastal horseshoe crabs which were most probably washed up by the waves (picture below). First 'discovery'!
Discovery Note:
Horseshoe crabs have known to 'roam' the earth since days even before the dinosaurs was around, so scientists calls them 'living fossils'.
Although they are called horseshoe crabs, they are not related to crabs. They are actually more related to spiders and scorpions.
There are two types of horseshoes crabs which we can find in Singapore, the mangrove one (circular tail) and the coastal one (the trianglar tail)
The tail is not venomous and is not used as a weapon. It is merely used as a lever to right itself if it is overturned. If you see an upside down horseshoe crab struggling with its tail waving around, do give it a helping hand. It will not hurt you.

The blood of the horseshoe crab is blue, as it is copper-based.
Their blood is able to clot easily when it detects bacteria, so their blood was harvested for these purposes until a team from NUS's department of Zoology has cloned a substance to replace using horseshoe crab's blood. Read more about it here.

Second 'discovery' was a find by our hunter seekers. A flat worm (picture below).
Discovery Note:
Flatworms are hermaphrodite, which means a flatworm has both the male and female sex organs.
And certain species of flatworms engage in penis fencing, in which two individuals fight, trying to pierce the skin of the other with their penises; the first to succeed inseminates the other, which must then carry and nourish the eggs.

And we also saw lots of turban shells. Here's one of them, third 'discovery' (picture below).
Discovery Note:
1. The door to the shell opening (operculum) is thick and rounded.
2. The hemi-spherical operculum is called a 'cat's eye'.
3. These ‘cat’s eyes’ are sometimes used as buttons.

During our walk, we also spotted lots of hairy crabs, red, green egg crabs
and a mosaic crab which are all poisonous! We also saw a few black sea cucumbers and of course barnacles! But I forgot to take photos of those. =P

Anyway, here a group shot of everyone, inclusive of guide (picture below)And as our walk came to an end, the tide was also rising. Wow, look at the difference compared to the first photo (picture below).Finally, it's thanks to David, Edwin and the kids of course for making this trip another interesting and fun outing. And of course, everyone who turned up! =)