08 January 2012

Signs of dugongs at Chek Jawa

Today, I saw many signs of what seems to be dugong feeding trails on Chek Jawa!
I was out with determined TeamSeagrass volunteers who monitored despite the rain. I also did a quick check to see if Chek Jawa has been affected by recent flooding in Johor.

After the monitoring, I had a quick look around to see if there were any signs of ill health due to the recent flooding in Johor and heavy rains in Singapore. In 2007, Chek Jawa suffered mass deaths following heavy flooding in Johor. In fact, we observed mass deaths during the first ever TeamSeagrass monitoring which was held at Chek Jawa in Jan 2007!
Lots of Carpet anemones (Stichodactyla haddoni) both in the water and on the sand bar. Most of them looked normal, although some were 'squished' up probably due to the rain. I didn't come across any that were 'bleaching' or bloated, which is what happened in 2007.
I came across the usual assortment of creatures. Lots of Striped hermit crabs (Clibanarius infraspinatus), many sand collars which are the egg mass of moon snails (Family Naticidae), one lovely egg case of the Noble volutes (Cymbiola nobilis) although I didn't see any of these snails. I also saw several sponges growing in the seagrass meadows, as well as many orange ascidians. I also saw a few cerianthid aka peacock anemone.
There were many swimming crabs (Family Portunidae) among the seagrasses. They can be quite fierce!
There were also many other egg strings among the seagrasses. I think the one on the left are laid by some kind of slug (though I didn't see any today), and the one on the right is laid by Gong-gong snails (Strombus turturella).
I only saw a few Thorny sea cucumbers (Colochirus quadrangularis), there are usually a lot more of these.  I was glad to see several Garlic sea cucumbers (Holothuria scabra) which is believed to play an important role in seagrass health. I didn't come across any Ball sea cucumbers (Phyllophorus sp.) today.
There were also many Cake sand dollars (Arachnoides placenta). But I didn't see any sea stars.
I also came across a thick swarm of what looks like slender shrimps. They were very hard for Small Sneaky Cam to photograph.
There were many different kinds of shorebirds feeding on the seagrass meadows today. These migratory birds need to feed on mudflats and shores like Chek Jawa to fuel their long distance flights.
In the distance at the surf, were the usual cluster of Terns which are seabirds that feed at sea but rest on the shore. Among them, two large Great billed herons.
It was heartening to see several long narrow furrows in the seagrass meadows which are probably dugong feeding trails!
Here's another series of dugong feeding trails.
These trails are at the same area where Dr Dan first spotted what seems to be a dugong at high tide from the Jejawi Tower. I do hope these are signs that dugongs have recently visited Chek Jawa!
The seagrasses meadows seem to be doing well. Here's a glimpse of the wide variety of seagrass species that can be found at Chek Jawa.
I am particularly impressed by the extensive growths of Smooth ribbon seagrass (Cymodocea rotundata). As far as I've seen, this is the largest patch of this kind of seagrass in Singapore. Smaller patches have so far only been seen at Cyrene Reef and at Tanah Merah.
Seagrasses commonly seen at Chek Jawa include Spoon seagrass (Halophila ovalis), Needle seagrass (Halodule sp.), Fern seagrass (Halophila spinulosa) and I was glad to see some small patches of the rare Beccari's seagrass (Halophila beccarii). There's an article about Singapore and this rare seagrass in the latest issue of Seagrass Watch.
The Goh family who are joining TeamSeagrass for the first time spotted this jellyfish. They suspect it's a box jellyfish which can give painful stings and can be a danger to swimmers. Alas, this is the best photo that feebly Sneaky Cam can take.
As usual, I am on the look out for abandoned driftnets. The only ones I came across have been on the shore for such a long time that animals such as sponges are growing on them. We leave these on the shore as they are no longer a serious threat to marine life.
On the way back, I have a quick look and the Critically Endangered Delek air (Memecylon edule), a rare coastal tree, is fruiting!
The mangroves look fine too. Chek Jawa is now easy to explore from the boardwalk. The mangroves are particularly fascinating. For a fun time, join the monthly Naked Hermit Crabs free public walks aimed especially at families.
As we were rushing back to avoid the incoming storm, I bumped into this group who were very keen to learn more about Chek Jawa. They had Andy take a group photo of them. Sadly we spoke only briefly as the storm caught up with us.
I'm glad to see that Chek Jawa so far seems to have escaped another mass death situation this monsoon season.

3 comments:

  1. Great story and photos as always Ria. Good news about the Dugong trails. Wishing you and your sea grass and reef companions many similar happy days in 2012!

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  2. Thanks for dropping by the blog Russell and Happy 2012 to you too! You are doing awesome work on your shore!

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  3. Thanks Ria If I could do half as much as you I would be thrilled mate! Your photos always inspire me!

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