Monday, November 24, 2008

Bug hunting in Singapore Polytechnic (SP) (19 Nov 2008)

This time, I turned my attention to my very own campus to find out just how well established are the bug populations in our ponds.

The first pond is a relatively long one (~ 20m) well stocked with Koi and other large fishes. It stretches along the boundary of the campus along Commonwealth Avenue West. This is a really cool idea as it acts as a fence without installing a fence. With Esther's help, we combed through the bed at a few spots for bugs with the now familiar net. Besides lots of floating green algae, the whole place is a desert devoid of bugs. Oh, did I mention that the bed is made of an artificial stone? This, plus few aquatic plants and the presence of swarms of hungry fishes probably account for the bug free environment.

We next checked out the pond at the Eco-garden. "Eco-garden" sounds like an nice place to find a balance ecology. This is a smaller pond with nice landscaped waterfalls. Apparently, the name can be deceptive. With feet stamping on the bed of big rocks and net vigorously sweeping through the water, nothing turned up. (Is this a surprise or what?) The only "bug" we found was a snail shell (sans the snail) attached to an underwater rock.

Overall, SP has been a disappointment in its bug population. I guess that is what comes from making everything artificial.

Wednesday, November 19, 2008

Water Quality Monitoring in Bukit Timah Area: Ngee Ann Stream (18 Sep 2008)

We headed to this nice natural looking stream (affectionately termed "Ngee Ann Stream" due to its proximity to Ngee Ann Polytechnic) right after checking out Binjai Stream (see post below). But do not be mistaken about its naturalness... this stream will soon flow through a concrete tunnel before ending up in Ulu Pandan Canal.

At the first sampling point, we managed to net a big (~ 3cm length) damselfly nymph hidden in a bunch of waterside grasses and it is ALIVE! (We found a discarded exoskeleton earlier.) Regrettably, my camera is not good at capturing small objects so the pic is not posted here. However, other than the clearly irritated damselfly, no other macroinvert was netted though there were lots of hydrilla crowding one another out.
We tried our luck at bagging some macroinvertebrates at the second sampling point. No luck! We only found some gastropods (snails) firmly attached to underwater rocks. The other bug of interest is a cute looking, whitish Collembola (Springtail) inching its way across a rock surface.

It appears that our waters in Singapore are not exactly teeming with macroinverts. Do we have a problem here?
Figures (L - R): The scenic and natural open country freshwater stream that is Ngee Ann Stream; searching for bugs at the second sampling point; the naturalness giving way to stone and concrete; a surprising find - belukar (secondary forest) hidden next to the stream

Thursday, November 13, 2008

Water Quality Monitoring in Bukit Timah Area: Binjai Stream (18 Sep 2008)

I had the honour of being attached to the Marine Biology Lab in NUS for a week. During this period, I learned more about the use of macroinvertebrates in water quality monitoring. The attachment was made more interesting with a field trip to one of my favourite haunts for recreation and water quality monitoring.

Binjai Stream is located in the Binjai area of Bukit Timah. Casual trekkers are not likely to stumber upon the entrance to this stream as it involves wading through a long, dark tunnel under an expressway. The occasional inhabitants of the tunnels, swifts of some kind, fiercely demonstrated their displeasure at our intrusion by playing touch-and-go near our faces.

This can qualify as one of the cleanest streams we have monitored. Forests surround the stream and the clear waters are occupied by numerous pond skaters. Unfortunately, the area further upstream is subject to land slides, especially after heavy rains. This really messes up the water quality as the stream water quickly becomes "kopi susu" with high levels of suspended sediments.

Yet despite the clear and clean (indicated by water quality tests) water, the benthic macroinvertebrate population was surprisingly disappointing. Kick sampling with a net yielded little macroinverts. Most were surface insects such as pond skaters.

Is this a normal trend in our waters? Or could this imply something unpleasant festering in the background? We do not have the answer at this point.

Figures (L - R): A freshwater crab deftly scoped up; numerous pond skaters; Esther working on the net to score some macroinverts; typical habitat of Binjai Stream

Monday, November 10, 2008

Water Quality Monitoring at Nee Soon Freshwater Swamp (6 Oct 08)

(Updated on 20/2/13: Nee Soon Swamp Forest is a highly sensitive area that is off limits to the general public as the biodiversity may not be able to handle the visitor load. Special permission from Nparks must be obtained prior to entering the area.)

What is a freshwater swamp? I have always imagined what it would be like since I heard of this term many years ago.

Though I already have the answer a few years back when I explored the Nee Soon Freshwater Swamp some years back, I only get to know this place better in 2007 when I started my water quality monitoring programme there.

True to most accounts, the swamp water is really acidic, hovering around a pH of 3 - 4. Contrary to popular belief, many fishes can be observed in this acidic water. Whether they are acid stressed or truly adapted to the waters, I do not know. But most textbooks (from Western countries) will tell you that waters of such acidity will kill a fish really fast. Perhaps, the authors have yet to visit a freshwater swamp.

Other than the acidity, the water is really clean (visually, physicallly and chemically), as to be expected of a forest reserve with little human activity. Despite occurences of high colifom count (in 2007) and high chloride content (Oct 2008), these by themselves do not indicate pollution as natural factors could also have given rise to such occurences.

If you have not been to this place, I strongly urge you to give it a try as it is the "only" freshwater swamp in Singapore. (Please take note of the update at the head of this post. I am an advocate of natural conservation so in no way should you act irresponsibly towards the environment and the biodiversity there.)  (I believe the highly restricted Western Catchment has some more.) It is definitely a welcome change from the conventional primary and secondary forests that you may have gone before.

Figures: Water pipelines. As the name "swamp" implies, part of the forest is always flooded. The water level may reach up to your knees or higher so please be prepared physically, if not at least mentally.

World Water Monitoring Day (WWMD) 2008 in Singapore Polytechnic

There really is a day for everything in this world, or so they say. Perhaps I should not be so surprised when I learned that there is such a day for water quality monitoring. It is organised by International Water Association (IWA) and Water Environment Federation (WEF) n USA. The coordinators in Singapore are Public Utilities Board (PUB) and Waterways Watch, Singapore (WWS). The main participants here are schools and polytechnics.

You can check them out here:


The actual day is supposed to be 18 Sep but the monitoring can be done anytime from 18 Sep to 18 Oct. This year, I have decided to submit my water quality data as part of our national effort.

As WWMD is more about raising awareness on the importance of water quality, its requirements are very basic. Simply perform your water quality monitoring in the stipulated period based on 4 parameters - temperature, pH, turbidity, dissolved oxygen (DO), in any water body of your choice. However, you may want to check with PUB or WWS to "reserve" your favourite site.

My data were collected from Sungei Buloh Wetland Reserve (SBWR), Sungei Mandai Besar and Nee Soon Freshwater Swamp. However, my data also include E. coli count, chemical oxygen demand (COD), nitrate, phosphate, ammonia, electrical conductivity since these are part of my normal water quality monitoring programme.

Parties interested in future WWMD activities may contact PUB or WWD or email me for the contact.

Thursday, November 06, 2008

The future of water quality monitoring in Singapore: bugs, macroinvertebrates and biotic indices

Bugs... If you think bugs are yucky, think again as Singapore will be incorporating bug sorting and counting as a tool in water quality monitoring in the future. Lots of developed countries are already doing it e.g. USA, UK, Australia. Even Malaysia, Thailand and Vietnam have gone ahead much further than us in this area. These countries have established biotic indices and protocols (to various extents) relevant to their environments.

And what are we doing?

We have employed a handful of expatriates researching on our very own local aquatic bugs. There is a group working on streams and canals while another group is working on our reservoirs.

As expected, lots of work has to be done in the identification and quatitation of local bugs before any useful index or protocol can be created. Of course, this also means that there is much potential in the study of aquatic macroinvertebrates (insects, worms, crustaceans, molluscs, zooplankton etc.).

Ultimately, our current physical, chemical and microbiological monitoring will be coupled to biological monitoring to provide a complete picture of our waters' health. Meanwhile, you can start to love bugs more or better still, learn about them and how they serve as useful environmental indicators.

Our beautiful bugs (L-R): Dragonfly nymph (O. Odonata, S.O. Anisoptera, F. Libelluidae), Non-biting midge larva (O. Diptera, F. Chironomidae), Mayfly nymph (O. Ephemeroptera, F. Caenidae)