15 December 2016

How are the corals at Cyrene?

We saw Cyrene suffer from full blown mass coral bleaching in Jun 2016. Bleaching was still seen here in Aug 2016.
Today, a small team return to survey the situation. While I didn't come across any corals that were full on bleaching, some of the large corals had pale patches and I saw many signs of recent death.

Ironically, it's difficult to spot the corals when they are not bleaching! I feel that I saw fewer corals today than on our Aug 2016 trip and much fewer than on our Jun 2016 trip. The bloom of seaweeds that covered the reef flat in Aug 2016 is gone.
Many of the large coral colonies were not totally bleaching, but had patches that were pale or yellowish, and portions that look recently dead.
Pale patches (white arrow) shows the coral is still alive but probably stressed. Coloured portion (blue arrow) show healthier coral. Recently dead portion (red) has algae growing on coral skeleton.
Others had small dead patches.
Another coral that is nice and brown, but the bottom layer of the colony appears to have died recently.
I saw a few Anemone corals and Small goniopora corals, they seemed alright.
I saw one small Sandpaper coral and one small Cauliflower coral. They were not bleaching.
I saw a few Flowery disk corals that were mostly alright, and one small Thin disk coral. Most of the Boulder pore corals I saw were alright. I didn't see any Brain corals.
Most of the corals I saw were Merulinid corals (formerly Favid corals). There were many small colonies that look alright. Some had small pale patches or small dead patches.
Some of the bigger colonies also had pale patches and dead portions. I also saw some that were mostly recently dead or mostly pale or completely recently dead.
I saw some Leathery soft corals and most of them were not bleaching.
Most of the leathery soft corals were nice and brown.
I only saw one Asparagus flowery soft coral, it was not bleaching. I saw a variety of Leathery soft corals, all not bleaching.
When leathery soft corals are stressed, they appear to 'melt'. Perhaps to avoid 'putting all the eggs in one basket', by breaking up into smaller colonies? So hopefully, some of the smaller colonies would survive.
I saw two Giant carpet anemones, one Haddon's carpet anemone and one Frilly anemone. None of them were bleaching. We didn't see any Snaky anemones.
Cyrene also has lovely natural sand bars teeming with Common sea stars and other burrowing animals.
Cyrene is not just a reef. It also has vast seagrass meadows, probably among the best in Singapore. There were good growths of seagrasses in the small area I surveyed. I saw a few Knobbly sea stars; the team says these sea stars have now congregated on another part of the shore.
Although there were many large patches of 'burnt' grass.
A quick look at the seagrass area before sunset. There were many Fan shell clams, a few White sea urchins, some small colonies of Montipora coral (not bleaching), a Vermillion flatworm and lots and lots of Ornate leaf slugs.
This looks different and might be a Wooly leaf slug.
This looks like a boat strike. A deep gouge in the reef flat with a row of ploughed up rubble, probably caused by a boat striking the reef at lowish tide. But it looks like seagrasses are starting to colonise the bare areas of the gouge.
Juria came across an abandoned net.

Sam also came across a large fish trap on the reef.

Cyrene lies in the middle of the industrial triangle made up of the massive industries on Jurong Island, huge refineries on Pulau Bukom and the world-class container terminals at Pasir Panjang. And yet it has rich marine life.
The last time I saw the corals on Cyrene bleaching was in 2010. They since recovered from that. I do hope that the corals will recover from mass bleaching again this time.
We landed in the late afternoon thanks as usual to Alex and James who bring us to strange shores all year round. What makes up for some of the sad sightings on our shore surveys is the happy companionship of the team. I miss them this time of the year as there are fewer low spring tides.

Photos by others on this trip
Others on this trip: Nicholas Yap, Jianlin Liu, Jacqueline Lau, Sam Yeo, Dayna Cheah.


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