Mass coral bleaching starting in Singapore in 2013?

There were signs of mass coral bleaching at Terumbu Hantu when we visited on 28 Jun 2013.

Karenne Tun and Debby Ng also shared signs of bleaching on other shores. What is coral bleaching and what can an ordinary person do?


At Terumbu Hantu, about 10% of the leathery soft corals (Family Alcyoniidae) I saw were bleached or partially bleaching. I saw two Asparagus flowery soft corals (Family Nephtheidae) that were still purple. Other bleaching animals I saw were on small patch of Sea mat zoanthids (Palythoa tuberculosa) and a few Frilly sea anemones (Phymanthus sp.). But most of these animals were not bleaching.

These Circular mushroom corals (Fungia sp.) were all bleaching.

Kok Sheng also blogged about these bleaching animals at Terumbu Hantu. Like this Carnation coral (Pectinia sp.).

Photo by Loh Kok Sheng.

A rarely seen Cabbage coral (Trachyphyllia geoffroyi).

Photo by Loh Kok Sheng.

Also a bleaching Bubble tip sea anemone (Entacmea quadricolor).

Photo by Loh Kok Sheng.

In May 2013, we came across some corals that were partially bleaching at Pulau Hantu. I was hoping it was a localised issue as I had already observed a similar situation our Nov 2012 trip there. They were of various species. All the Asparagus flowery soft corals (Family Nephtheidae) were still purplish but many had yellowish tips. Most of the bleaching corals were seen at the mouth of the lagoon facing Pulau Bukom, although I saw a few on the reef flats too.

I've started a slide show of bleaching animals that I come across in 2013.

Created with Admarket's flickrSLiDR.

On 29 Jun 2013, Karenne Tun shared on facebook this photo with the following comments:

Photo by Karenne Tun

"Sea surface temperatures in the region are edging up to uncomfortable levels. Although not at the point of trigging mass bleaching, initial signs of thermal stress have been observed on Singapore reefs.

Last Wed (19/6), some initial signs of coral bleaching was observed at Kusu Island N. Nothing major at that point in time, just paler coloured corals affecting around 10-20% of the reef community.

ne week later on Thu 27/6, signs of intensified bleaching was observed at Pulau Hantu, where an estimated 30% of the reef community showing signs of partial bleaching.

Again, at this point, no wide spread bleaching was observed. The NOAA Coral Bleaching alert have put most the region at Bleaching Watch, and this has been confirmed by local SST monitoring. A check with colleagues in the region indicate that some initial bleaching have been observed in Malaysia and Philippines.

This is a call out to all divers and concerned individuals to keep an eye out for our corals. Please post sightings and photos if you have them."

On 4 July, Debby Ng of the Hantu Bloggers reported bleaching at Terumbu Raya on 5 Jun 2013 and shared this photo.

Photo by Debby Ng

I usually check with the NOAA’s Coral Reef Watch which gives predictions of global coral bleaching. 26 Jun 2013 mapping shows the area in Singapore's vicinity is under watch for bleaching (green).

Today, it looks like this.

You CAN make a difference!

• Learn about mass coral bleaching: In this blog and check out Karenne Tun's presentation done for the 1988 bleaching event.
• Report sightings of coral bleaching at the resources listed below. Share photos and any observations you have.

Keep up with the situation in Singapore through the Bleach Watch Singapore facebook page.

And in Asia through the Bleach Watch Asia facebook page.