There is a secret lagoon on Seringat-Kias opposite the Business District on mainland Singapore. This small opening in the seawall connects the lagoon to the sea.
We came to see the tiny box jellyfish that have been noted to thrive here. Thanks to guidance from Mathias Luk, we were not disappointed! We also checked up on the super rare mangroves thriving here, and had a quick look at Eagle Bay. Sadly, seagrasses there are still not doing well.
We had a close look at lots and lots of box jellyfish and absolutely no one got the littlest sting. Thanks to Loh Kok Sheng for photos and ID of the Mangrove box jellyfish (
Tripedalia cystophora) "which is not known to inflict significant venom on humans. This species can be observed in abundance, among half-submerged roots, in shallow, muddy waters of mangrove swamps." From
Iffa Iesa's Singapore Biodiversity Record.
Rant ahead: Yes, it's true that some box jellies can be very dangerous. But as our survey shows, it is possible to see them without being harmed. Exploring our shores and enjoying water sports is like crossing the road. If you keep a watch out and are properly prepared, it is quite safe and you can easily AVOID getting hit by a bus.
NParks has comprehensive advice on how to avoid getting stung by box jellyfish and what to do in a stinging situation.
Imagine a post about crossing the road that screams: "Buses can kill you! Here's more facts about buses and the incidents when they killed people!" Most rational thinking people will realise this is ridiculous. A bus does not normally intend to hurt people. If we pay attention when we cross or use the road, we will not be hurt by a bus. Most reasonable people will wonder why the post doesn't outline road safety protocols.
 |
Image by sonmez karakurt
|
It is the same with marine life. Yes, many can harm people. But we can safely explore our shores if we do it mindfully. We will not only avoid being hurt (and hurting animals) but also better observe the wonders of the sea. So please DO visit our shores, with proper preparations. Posters who only highlight 'dangerous' animals without also sharing how to avoid getting hurt. Such click-bait only want your fear, disgust, outrage. They don't really care about helping you make safe, positive connection with our shores. End Rant.
The team had a closer look at the narrow break in the seawall which joins the Mangrove Lagoon to the sea. They found many corals of various kinds. As well as large cowries, sea anemones, flatworm, fanworms. Seringat Kias lagoons is proof that marine life can return to artificial shores quite rapidly. From mangroves to seagrasses, to corals and reef life. On its own, without planting. Imagine how much more beautiful it can be if we build it so marine life can settle more quickly!
 |
| Collage of photos by the team. |
Besides patiently waiting for box jellyfish to emerge from the darkness, the rest of the team also saw lots interesting marine life in the Mangrove Lagoon. Super tiny swimming anemones with very few arms floated by photo-bombing the jellyfish hunt. There were also tiny Pygmy squids, many juvenile fishes, common swimming crabs. At dawn, lots of Fiddler crabs emerged while mudskippers of all kinds frolicked by the water's edge. There were also Common sea stars! And possibly Hairy spoon seagrass (which I saw on my last survey on
Nov 2020).
 |
| Collage of photos by the team. |
Today, I had a quick look at the eastern arm of the Secret Seringat Mangrove Lagoon. I saw many
Api-api jambu (Critically Endangered) from small shrubs to about 2m tall trees almost every 5 steps. As on my last survey on
Nov 2020, all were blooming and producing propagules. But almost all of them had curled up or chewed up leaves. While the other mangrove trees were crammed against the steep edges of the lagoon, most of the Api-api jambu grew further into the water. During my survey of the entire Mangrove Lagoon on
Nov 2020, I saw probably 50 Api-api jambu including about 10 very tall trees (8-10m tall) on the western arm which I didn't visit today. I first saw these rare trees in
Nov 2014 but there were not that many at that time.
In the brief survey of the eastern arm, I also saw several other kinds of rare mangroves:
Tengar merah (Endangered),
Bakau pasir (Vulnerable). And also common ones like
Perepat,
Tumu,
Api-api bulu as well as a wall of
Bakau putih on the high shore, where they usually thrive. All the trees were healthy and robust looking.
It was great to see seagrasses on the low water mark. Spoon seagrass with tiny leaves, Needle seagrass with broad leaves, and in deeper water Tape seagrass with long leaf blades!
The team also came across an abandoned fishing net in the Mangrove Lagoon. With the remains of a trapped crab entangled in it.
 |
Photos by Tommy Tan
|
I had a quick look at the northern arm of the large artificial Seringat-Kias lagoon (also called Eagle Bay by boaters). There were dense sprinkles of
Needle seagrass (narrow leaves) and
Spoon seagrass (tiny leaves) at the mid-water mark. Also lots of large
Oval moon snails, I saw one Common sea star, one tiny
Margined conch and one tiny
Pink moon snail. There were several common ghost crabs and hermit crabs, as well as many tiny gobies. On our last survey of Eagle Bay in
Oct 2024, there were still signs of oil slick 4 months after the oil spill. Today, I am relieved not to see any and the sand 'processed' by the
Acorn worms seemed nice and clean.
Today, I only saw cropped
Tape seagrass growing on the shore. And lots of long leaf blades washed up on the high shore, together with broken of blades of other kinds of seagrasses. I couldn't see any seagrasses growing in deeper water, but the tide wasn't very low and the water was murky. It seems the seagrass situation has not improved since our last survey in
Oct 2024, four months after the 400tonne
Pasir Panjang oil spill. At that time, about 50% of seagrasses seemed to have disappeared. It was mostly bare sand on the mid-water mark where there used to be dense growths of seagrasses. In deeper water, also appears to be bare of seagrasses. Tape seagrass was also cropped.
Kelvin checked out the northern arm of Eagle Bay and it seems the seagrasses are still there, although he saw Tape seagrasses that were cropped. In the sand, the usual crabs and moon snails, plus a sign of the rare thick-edged sand dollar. On the seawalls he saw hard and soft corals, also Long spined black sea urchins and common reef fishes.
 |
| Collage of photos by Kelvin Yong |
On the way back, we had a closer look at a set up that was part of
SiReNT (Singapore Satellite Positioning Reference Network). This is an ultra-precise satellite navigation network that can be used, among others, to study coastal erosion and natural habitats. The information panel explains how it measures sea level rise. How marvelous!
Massive reclamation created Seringat-Kias, which buried the submerged reefs of Seringat and Kias and connected it to the natural Lazarus Island. A causeway bridge joins these with St. John's Island.
Seringat-Kias was created by reclaiming two submerged reef flats: Pulau Seringat and Terumbu Kias. The old boat operators still call the place Renget. More about the reclamation and development in this
old blog post which highlighted how lots of money and effort was made to make the artificial Seringat-Kias lagoon look natural: "In 2006, massive landscaping was reported of the 1km reclaimed beach on Lazarus to simulate a natural environment so that it would look 'natural and wild'. 5,000 lorry-loads of soil measuring two storeys high when piled up were brought in by barges, an entire coconut plantation in Malaysia was bought, about 1, 000 trees was trucked and shipped to the island." Meanwhile, the neglected secret 'mangrove lagoon' became lush naturally, without any additional cost.
 |
| from the Southern Islands Development Guide Plan (DGP) 1996 |
Lazarus Island in the Singapore Blue PlanThe cluster of Kusu, Lazarus and St. John's Islands has been recommended by the Singapore Blue Plan 2018 for elevated protection status.
 |
Kusu Island and Lazarus Island
from Seringat Kias today |
The Blue Plan highlights that Lazarus, St. John’s, and Kusu Islands are established sites for coral nurseries as their shoreline offers ideal sheltered areas for growth of corals. Designating these islands as No-fishing Areas can bolster their rehabilitation. Protecting a larger cluster of islands means zonation plans for use can be implemented to manage tourism and human impacts.
DOWNLOAD the Plan, SUPPORT the Plan! More on the
Singapore Blue Plan 2018 site.
Photos by others on this survey
Loh Kok Sheng Kelvin YongTommy TanAdriane LeeRichard KuahIsaac OngLon Voon OngMathias Luk
