Mass coral bleaching at Tanah Merah Ferry Terminal

Today, a small team returns to survey the amazing coral reef that has settled naturally on the seawalls of Tanah Merah Ferry Terminal. There were lush seagrasses on the shore next to the Ferry terminal. 

Sadly, we saw signs of oil on the shores and also extensive mass coral bleaching (about 30%) and coral deaths (about 20%). But otters were seen and the seagrasses seem alright.

Our shores are currently being impacted by mass coral bleaching. So it was not surprising to see this happening on the corals that have settled naturally on this artificial shore. I do not know how to distinguish whether bleaching is due to the stress of higher water temperature or impact of the 400tonne Pasir Panjang oil spill on 14 Jun 2024. I estimate about 30% of corals were bleaching outright.

It was sad to see about 20% of the corals recently dead or with dead portions. Some were dying now (greyish blue), some died recently (thin fuzz of encrustations). Hopefully, the bleaching event will pass and our corals can recover.

Not all the corals were bleaching or dying. I estimate about 50% were still alright. Many were completely okay without any portions bleaching or dying. These included corals of all forms - branching, boulder, plate-forming.

Sand has started to fill up the seawall area, and this now covered a larger area than before. It makes it easier to survey, but has also meant fewer corals.

Many corals have also settled on the seawall that forms the lagoon next to the Ferry Terminal. Most are boulder shaped species, but there were also many branch and plate-forming species. Small to medium-sized colonies, many are well formed. Unlike the outside of the seawall and next to the Ferry Terminal, most of the corals here seemed alright. There were a few that were bleaching, and some with signs of recent death.

Other cnidarians can also bleach. So it was a relief to see that most of the anemones were alright. Only one Fire anemone was a little bleachy. We saw two Snaky anemones, one Giant carpet anemone, Frilly anemone. They were alright.

It seems, right now, according to the NOAA prediction for the Singapore Strait, the bleaching situation for Singapore is at "Watch". And expected to stay that way for the next 12 weeks.

During our last survey in Jun 2023, most of the Tape seagrass had long or very long leaf blades. Today, most of the Tape seagrass I saw had cropped leaf blades. The longest leaf blades I saw was about 30cm. A few had female flowers that appear to be about to bloom. But it was good that there were still many clumps well distributed throughout the shore.

The big patch of Smooth ribbon seagrass is still huge. Similar to what I saw in Jun 2023, it is now about 15m wide and grows from the low water mark to the seawall. But the few small patches of this seagrass nearer the ferry terminal seem to have disappeared. There are now many large patches of Sickle seagrass with fresh leaves. One patch had very cropped leaves, but the others seem alright. I failed to see any Spoon seagrass, which in the past was the most abundant species, growing almost throughout the shore.

The otters appeared at dawn and only Tommy saw them. Other special sightings include the clown anemonefish (separated from the host anemone at low tide), spotted by Lon Ong. Tommy also saw a Knobbly sea star, the little green goby that lives among branching hard corals and other colourful reef animals.

All photos by Tommy Tan.
Links to his album below.

There are still a lot of large Fan shell clams in a large area. I saw a few Common sea stars scattered in sparse groups. There were many Cake sand dollars and Oval moon snails. The sandy areas remain alive with signs of living worms and crab burrows. Also seen: Spider conch, and several Spotted orange hermit crabs.

There are some signs of the 400tonne Pasir Panjang oil spill on 14 Jun 2024, about a month ago. On the reefy seawall at the Ferry Terminal, there was a sheen of oil on the water. In the lagoon next to the Ferry terminal, there were large thin slicks on the water, with brown stains on the sand and small slicks among seagrasses. But I didn't see any oil on the seawalls.

On the high shore, a narrow line of litter is accumulating - quite 'good' for a shore that is not cleaned daily. Oil-coated marine litter means oil stays in the system for a longer time. Fortunately, not many of the plastic litter was coated in oil. But there were many single-use water cups, which commonly wash up on beaches along the ferry routes. These are not commonly used by beach goers or the local boating or fishing community. But these single-use water cups are apparently given out to passengers on ferries. It seems no facilities are provided at any of the piers/terminals under MPA's charge for vessels to responsibly dispose of trash generated during their operation. More in this post.

Where did all these corals come from?

The babies of these corals are from Singapore reefs! This chart shared in the Long-Term Plan Review shows coral larvae (babies) dispersal in our waters from mass coral spawning. This highlights the importance of protecting our 'mother reefs' so that they can continue to produce babies that settle all along our shoreline.

What is the fate of this shore?

Massive reclamation is planned near the area we surveyed today as outlined recently in the Long-Term Plan Review.

We restarted surveying this shore in Jun 2022 after a break of nearly ten years. This shore is now strictly off limits without a permit. We surveyed with permission from agencies kindly arranged by NParks and support from the Ferry Terminal.

Photos by others on the survey

Tommy Tan



Others on this survey: Ian Mun, Lon Ong