Mandai mangroves (10 Apr 2011)

Early Sunday morning, a group of enthusiastic volunteers gather to survey a sandy stream at Mandai mangroves.

It's a lovely cool morning, with lots of big mangrove trees around us, and NO soft mud! Hurray!

To get to the mangroves, we plough through a lallang field, walk a little way along the railway tracks, hop through some mud before getting to the lovely stream for our survey.

Here's the team of volunteers all ready to do the survey!

Compared to our most recent trips with super soft mud, this survey was a breeze! The large lovely Sungei Mandai Besar with a nice firm sandy bed allows us to easily do our work.

Here's a little clip of the team getting started on the survey.

In the mangroves, this is our 'locker' for mud-free storage of our bags.

This mangrove has the railway on one side, and a heavy industry area on the other. So what kind of creatures can we find here?

As usual, the mud is teeming with worms! In the harder mud, there are lots and lots of crabs! We find several different kinds.

And this looks like a Mound crab (Sarmatium germaini), which is listed as Endangered in the Red List of Singapore plants and animals. Wow!

A lot of flatworms have also been found!

The sandy stream is full of tiny little snails!

And lots and LOTS of big juicy looking clams. These are Geloina clams (Geloina sp.) also called Lokan, which Dr Tan first explained to us at the Admiralty Park survey.

We also found two little gobies. This is one of them.

We also come across many Mangrove horseshoe crabs (Carcinoscorpius rotundicauda). Most of them were males (in which the first pair of legs have bulbous pincers which are used to hang onto the female). We only saw two females (which lack the bulbous pincers). More photos of the male and female legs of horseshoe crabs.

We release the horseshoe crabs after Shufen takes photos of them. The transect tape comes in handy to show their size.

Volunteers also take photos with the horseshoe crabs before they are released.

The much awaited highlight of any survey is the final debrief by Dr Tan Koh Siang from the Tropical Marine Science Institute as he explains more about what we have found.

It's also a chance for everyone to take a closer look at the many fascinating creatures we have found!

The most exciting find was little yellow spheres which might be horseshoe crab eggs! These were found in the sandy areas which as Dr Tan explains is not that common in mangroves. Wow, we are discovering all kinds of fascinating things about our mangroves by taking a closer look at the mudflats! More about horseshoe crabs at Mandai and Kranji on the wild shores of singapore blog.

Sean took a video clip showing movement inside the egg!

Here's some excerpts of Dr Tan's briefing where he explains the special features of the mangroves at Mandai, and highlights two special finds: a 'Miso-clam' which he hasn't seen in Singapore for many years, and the horseshoe crab eggs!

And here's the team of volunteers at the end of another satisfying survey!

The video clips were taken with the awesome FLIP video camera kindly supplied by Shaun Quek of Cisco through the introduction of fellow volunteer Sam Yeo.

Other posts about this trip

• Sean on facebook with horseshoe crabs, their eggs and more. Also a video clip of something moving inside the horseshoe crab egg.

There's more work to be done after the field session, to process, sort and identify all these fascinating creatures. Look out for more news on how you can help out in this as well.

Upcoming trips for the rest of the year have been announced on the mailing list for registered volunteers. Exciting destinations include Lim Chu Kang mangroves.

To join us, register your interest in this form and you'll be invited to join the mailing list to receive updates on the Survey and sign up for Survey activities.

Also check out our FAQs for more about the Survey.

To find out more about our common mangrove wildlife, check out the online Guide to the Mangroves of Singapore and the wildsingapore wild fact sheets.