05 November 2017

Chek Jawa survey with scum on the water

On our way to Pulau Ubin, I saw wide swathes of floating scum. Others reported seeing similar scum in the area since 4 Nov. Is it some kind of pollution?
Pollution in the East Johor Strait?
At Chek Jawa, I saw oil spill booms laid out on the boardwalk and small patches of lightly bleaching seagrasses. Alas, the team also came across an abandoned net in the middle of the Chek Jawa lagoon. But otherwise, the seagrass meadows were fine.

I saw some patches of lightly bleaching Spoon seagrasses on both northern and southern Chek Jawa.
Bleaching Spoon seagrass (Halophila ovalis), Nov 2017
The water on the southern side of Chek Jawa facing the Johor River was the colour of teh susu (milk tea). Which is not unexpected given the recent rainfall.
Needle seagrass (Halodule uninervis)
Some booms were laid out on the Chek Jawa boardwalk.
Oil spill booms laid out on Chek Jawa Boardwalk, 5 Nov 2017
I saw this fish trap in the middle of the Chek Jawa lagoon. It was already disabled.
Disabled fish trap on Chek Jawa
The rest of the team also saw an abandoned net in the middle of the Chek Jawa lagoon. Estimated to be about 30m long.

The net continues to trap a lot of fishes.

More photos by Rene Ong on her page.

Despite these pressures, Chek Jawa is still very much alive!
Living seagrass meadows of Chek Jawa, Nov 2017
There were a lot of Garlic bread sea cucumbers of all sizes. Also many Pink warty sea cucumbers and some Thorny sea cucumbers. I saw one Smooth sea cucumber and one Beige sea cucumber. We came across one Knobbly sea star, but the rest of the team saw lots more. There were also lots of brittle stars.
It was nice to see many Cake sand dollars. And their predator, the Grey bonnet snail, which we saw for the first time on Chek Jawa in Dec 2016. I also saw one Tiger moon snail and many many sand collars. And Gong gong snails as well as hermit crabs. There were also many Cerianthids. Seagrasses are also great for egg masses and animals to settle on.
On the Southern sandbar, lots of Straw tubeworms. But alas, I couldn't find any living Button snails.
Straw tubeworm (Family Chaetopteridae)
The seagrass meadows were lush. Mostly Spoon seagrass and Needle seagrass, with some patches of Fern seagrass. Closer to the boardwalk, Smooth ribbon seagrasses are still lush. We saw dugong feeding trails!
Dugong feeding trail in seagrass meadows, Chek Jawa Nov 2017
There were lots and lots of Haddon's carpet anemones!  In 2007, there was mass deaths of Haddon's carpet anemones and other animals at Chek Jawa. This is believed to be due to heavy rainfall as marine life can't cope well with too much freshwater.
Fern seagrass (Halophila spinulosa)
The mangroves looked well.
Mangroves at Chek Jawa
The very rare Critically Endangered Mentigi (Pemphis acidula) is still there and looking alright. We saw under a fallen tree on our last survey in Jan 2016.
Mentigi (Pemphis acidula)
Thanks to NParks for permission to survey this shore and keep tabs on how it is doing.
Seagrass meadows of Chek Jawa

Posts by others on this trip

Others on this trip: Faiq, Koh Jie Min.

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