Pulau Jong (Resembling a 'Bao' )
While i must say, there are still many islands yet to visit, (i think i'm one of the few in the group who has not visited St. John's or Kusu yet) the focus here is to familiarise ourselves with the procedures of our guiding trip and it's great that Luan Keng actually began with Q&A session with us right from the start. [I know i really should be "kok-ed"at- to think that i didn't know (i really didn't know) the two VIPs that actually spearheaded the reafforestation project.]
I am surprised too as i learnt that 13 hectares of land with 400,000 mangrove trees are replanted in the project.
You might be wondering why mangrove trees are replanted in Semakau Landfill. The reason mentioned is because as a number of mangroves are previously destroyed, they wanted to restore them back and so one way of doing this is replanting. How then can we distinguish which among the trees are replanted? Look for those similar in height, compacted to one another and lighter in colour like the one below taken in one of my trips. As you can see in the pictures below, the replanted mangroves are those of the Rhizophora.
Replanted mangrove trees
Talking about mangrove trees, I've learnt a new fact today courtesy of Luan Keng. Mangrove trees are in fact very good filtering systems that they can detect minute amounts of heavy pollutants like Boron. This characteristic is especially useful because in a landfill area like Semakau, the authorities can detect if there are any chemicals being introduced in the waters by looking at the condition of the mangroves. Of course, in Semakau Landfill, there are also monitoring wells found along the cells. These wells test leachate and there is even a Leachate Treatment Plant in the island.
1)A monitoring well 2)Geofabric with layer of geomembrane to keep off chemicals
We had a quick tour of the Marine Transfer Station where we saw the barges which are used to contain the incinerated waste from mainland Singapore to Semakau Landfill. There are 2 barges coming in from the Tuas Marine Transfer Station everyday carrying thousands of tonnes of waste. This spells a lot about the amount of waste we throw down our rubbish chute. At the rate we're throwing our waste, Semakau Landfill would probably be filled up by the year 2040. Shouldn't we start to reduce, reuse and recycle?
1) Map of Semakau Landfill 2) Marine Transfer Station
Stockpile of incinerated waste where long-arm excavators dig up and later transfer them to trucks for tipping.
Tipping site where tipping cells are found for compacting & levelling of incinerated waste by bulldozers.
As we headed towards our southern most point of Singapore that can be accessed by the public, we spotted the great billed heron on the lagoon. This is in fact the tallest bird in Semakau and like the grey heron, it is a resident bird. Its unique name came from its long bill.
Once we are out of the mangroves, we are greeted by thousands of creeper snails and of course, it is thus important to drive the message that as much as we want to discover the marine life, we should rightfully create minimal impact as much as possible on the shores.
A creeper shell
As much as Semakau Landfill is a restricted area, it is a shame to find a poacher setting a number of such nets to trap marine animals along the way. Perhaps what we could do collectively is to petition that such acts should be strictly prohibited even implement some FINES system?
Net with some chicken feet to lure crabs
Ok depressing as it may be, here are some interesting finds from this trip which i hope to explain the uses/functions, whether they can be eaten and their sexual reproduction:
Baby mangrove horseshoe crab
Probably one of the living fossils on earth, the horseshoe crab has been around since the pre-historic age. Although it appears "aggressive" with its shield-like body and sharp tail, it is actually quite harmless. In fact, the tail is used to right itself when overturned.
Onchidium
Onchidiums are more closely related to land snails. They have simple lungs to breathe air. If you pick up an onch, try to place it back close to the spot where it had been previously. Can you see that their skin seem to match the colour of rocks and sands they're in?
Heart-shaped cockle
This is a good find as common heart cockles are not red. Heart cockles are bivalves, can you see that both sides are symmetrical to the other forming the heart shape? Unlike clams that open their mouths vertically, heart cockles open up horizontally.
Gigantic carpet anemone
Carpet anemones are cnidarians. have tentacles with stinging cells so do not touch it with your bare hands! This is a useful feature because the animals trapped in it will be entangled and paralysed thus serving as food for the anemone. However, not all animals will be trapped. Certain animals like the clownfish actually has a symbiotic relationship with the anemone. The anemone provides food and shelter for the clownfish away from predators while the clownfish attracts potential prey for the anemone.
Sea cucumber
The name goes because of its shape similar to a cucumber. Sea cucumbers are related to sea stars. They have a water-vascular system. This is why we should not take them out of the water for too long. What do they feed then? Sea cucumbers feed on decaying organic matter and plankton.
1)Ocellated sea cucumber 2)Sandfish sea cucumber
Synaptid sea cucumber is a little different in that it does not have tube feet. If you touch it, it seems sticky. Like the picture seen below, synaptids coils around sponges. Can you spot the "feeding tentacles"?
Flower crab is a type of swimming crab which we often find on our dinner table. For me, this is the only crab that i can eat due to my allergy. Flower crabs have legs that are flat so this enables them to paddle. Notice also the long pincers with sharp spikes. These pincers are used to snatch fishes and other fast-moving prey. Flower crabs move sideways but they can move back and forth too. As you can see from this picture, flower crabs often 'hang out' in waters because they cannot live out of waters for long periods unlike other crabs.
Mushroom corals
1)Mushroom coral 2)Sunflower mushroom coral
Mushroom corals do not form colonies unlike other soft corals. Usually, there is only a single polyp. They are called mushroom because when young, they attach themselves like mushrooms do to the reef. However, when they mature, they usually detach themselves and live on the seafloor.
Zoanthids
They also have stinging cells. They are in fact, colonial anemones. Like the picture seen here, the zoanthids actually form mounds on the rock. Caution, some zoanthids are poisonous.
Nudibranchs
They are a type of sea slugs because they are snails without shells. Most species have their gills displayed prominently. There is a reason why nudibranchs are very attractive. This is actually to ward off potential predators about how toxic they are. Often enough, we can find nudibranchs on sponges. What do nudibranchs feed on? Some species feed on on fellow nudibranchs while others feed on sponges and anemones. Which is why it is not advisable to keep nudibranch in a marine aquarium as it preys on others.
Can you spot the tentacles on the polka-dotted nudibranch? These are called rhinophores and it is believed to be used as a sensory organ to locate food and to find a mate.
Can you spot the exposed gills? 1) gymnodoris"orange spotted" 2)polka-dotted"oreo-cookie")
Knobbly sea star
Notice the tube feet on the underside of the knobbly.
So that's it for this session. I am looking forward to my OJT :)
