Category Archives: Mangrove Projects

3,500 International Coastal Cleanup volunteers hit the beach in Singapore today!


Since 1992, Raffles Museum Toddycats! has been organising International Coastal Cleanup Singapore. Since the beginning, there has been  3,000 volunteers by more than 50 organisations and schools!

“This year, more than 3,500 volunteers from some 80 schools, corporate groups and agencies went to beach and mangroves of Singapore early on 13th September morning to collect, categorise and remove trash from our shores – for the 22nd year!

We chose to work the low tide this week before the rest of the world conduct their cleanups on the third Saturday of September as identified by Ocean Conservancy, the international coordinator”

Read more on their work on

Also, International Coastal Cleanup Singapore also has a Year-Round Coastal Cleanups (YRCC) programme. Organisers from schools, institutions, corporate or other groups are always welcome to organise cleanups at any other time of the year on their own with some advise from us, after reading ICCS’ Guidelines for Organisers. More information on


2014 08 09 10 08 05 ndcc kpinto attendance


Are Singapore’s mangroves to remain ecologically-sustainable over the long-term?

In conjunction with the World Migratory Bird Day on 12 May 2012, Sungei Buloh Wetland Reserve (SBWR) organized several talks and an exhibition to celebrate the World Migratory Bird Day and   its role as  a roosting ground for migratory birds.

Although migratory birds were made the main focus of the event, mangroves and its mudflats that provide habitats for the birds were not neglected during the celebration.

Mangrove Maestro a.k.a. Dr. Dan Friess held an educational talk to SBWR’s visitors on the state of Singapore’s mangroves and how the public volunteers can assist NParks in their investigation of the current state the mangroves.

Title of Dan’s talk

Dan introducing title of his talk to his attentive audience

Highlights of the talk

Dan talked about mangrove loss around the world and in Singapore itself.

Evidence statements of mangrove loss worldwide

A substantial decline of Singapore mangroves was recorded since  the 1950s.

Singapore has lost a lot  of mangroves over the past 50 years. In addition, our mangroves  have been and are currently facing threats to their survival. To illustrate the threats faced by Singapore mangroves, Dan has used Mandai mangrove as a case-study to exemplify the threats.

List of threats faced by mangroves of Singapore

Sea level rise  (SLR) threat: mangrove  would survive and expand when the increase in surface elevation > increase in SLR.

Otherwise,  mangrove degradation and erosion, as seen in Mandai and Sg Buloh is  due to surface elevation < increase in SLR.

Sea level rise is dependent on surface elevation and sea level ; these factors affect life and death of a mangrove patch.

Damming of Kranji River has caused  a major loss of sediment input for Northwest Singapore mangroves including Mandai and Sg. Buloh-therefore leading to erosion i.e. reduced sediment input vs. sediment output

Dan also talked about the impacts on coastal reclamation which have led to disconnection of mangroves i.e. fragmentation  mangrove areas. For example, Mandai mangrove and SBWR are no longer connected as a Northwestern mangrove patch.

Another threat to survivability of mangroves: fragmentation!

So why mangrove  fragmentation is bad?

Mangrove fragmentation would eventually  lead to disturbance of  flora and fauna species near the edges of a mangrove patch. Sensitive animals would not be able to cross over to another mangrove patch to search for food, mating partners, etc and therefore may not survive.

Plant wise, some mangrove tree species disperse their young i.e. propagules to different places via water dispersal. Therefore, if  mangrove patches are disconnected, mangrove trees cannot disperse their propagules to neighbouring mangrove patches.

Different mangrove propagules of different mangrove species found in Singapore. Picture courtesy of Ria Tan from Wild Singapore

Rhizophora propagules disperse via water currents

Dan channeling his ‘wit’ by placing a Sonneratia propagule over his nose!

Illustration on how fragmented mangroves will influence the dispersal properties of mangrove plants

The disconnection often leads to short-term sustainability of mangroves i.e. mangroves will eventually die! Noooooooo….

Therefore, NUS and NParks are collaborating on several projects to investigate the scale of mangrove fragmentation  in Singapore by predicting  the sustainability of  Singapore’s mangrove.

Effects of mangrove fragmentation on mangrove dispersal

How  do we investigate the fragmentation status of Singapore’s mangroves?

Fruiting  and flowering seasons of our mangroves will be studied. Meanwhile, NUS PhD student Alison Wee is currently conducting research on gene flow of our mangroves.

Combined with data from a hydrodynamic model, the extent of the fragmentation in Singapore’s mangrove will be better understood in order to mitigate plans to save and conserve our mangroves from further loss.

Studying fragmentation of Singapore’s mangrove from several aspects


You CAN play a role in the project! How? NParks is looking for public volunteers who are interested to help collect, count and sort propagules of mangrove trees in SBWR.

Volunteers can assist this project by several ways

Please contact Dr. Friess at  if you are interested to help out with the project.

Andy has been kind enough to record the whole-length of the talk (thanks Andy!), feel free to watch the talk below:

Results of Rick’s Project for His Honour’s Project

Hi all,

Rick here. After eight month’s of  work on my final year project, I’m proud to announce some of the findings of the project. They are summarized in the poster below.

However, it is not the end of my project, I’ve got more trees to map and I need help from you! Refer to the end of the page for sign-up links to help me out with my project!

Here’s an overview of my project (for both new and old readers)


(1)Map the surface  elevation of Mandai mangrove

  • I am curious to know surface elevation of Mandai i.e. if the elevations in the mangrove are relatively the same at different mangroves?
  • What types of topography can be seen in Mandai?
  • Surface elevations will consolidated into a  digital elevation model (DEM)

(2)Map the vegetation of the mangrove, specifically mangrove trees

  • What types of mangroves tree species are found in Mandai
  • Are these trees clustered together? Is there  a difference in spatial distribution of trees according to species? and etc.

(3)Investigate if there’s a relationship between mangrove trees and surface elevation

  • Mangrove trees may be distributed according to species at different surface elevations
    • this could be due to adaptation of a specific species with the physical environment it lives in
    • different species have different strategies of dispersing their seeds; some mangrove fruits are able to propagate with floating propagules by wave action
  • Is there “mangrove zonation” in Mandai? i.e. distribution of  mangrove species found  at different distances from the shoreline

    Is zonation found in Mandai mangrove similar to the figure above?

Is zonation found in Mandai mangrove similiar to the figure above?


Where is Mandai mangrove?

It is located just next to Woodlands Checkpoint and the causeway. Here’s the location on Google Maps.

Q: How did I map my trees and surface elevation?

A: I used a total station

Trees and surface elevation were mapped using a total station which comprises of the optical machine(theodolite operated by JK), survey prism (held by Rachel) and target prism(not seen here).


Q: Did I managed to map every single tree in Mandai?A: No, however the tally so far  is 1490 trees. Mapped trees were focused at Mandai Kechil (near Mandai Kechil River) and in transects across the mangrove.

Q: How many species of trees did I mapped?A: 13 species, I only focused true mangrove species and those with tree girth of  5cm and above. They are

Species Species Code Family
Avicennia alba Blume


Avicennia officinalis L.


Avicennia rumphiana Hallier f.


Bruguiera cylindrica (L.) Bl.


Bruguiera gymnorrhiza (L.) Lamk


Ceriops tagal (Perr.) C. B. Robinson


Ceriops zippeliana Blume


Excoecaria agallocha L.


Heritiera littoralis Dryand. In Aiton


Lumnitzera racemosa Wouldd


Rhizophora apiculata Bl.


Rhizophora mucronata Lamk.


Sonneratia alba J. Smith


Xylocarpus gratanum Koenig



Q: What are some of the  endangered mangrove species that I have mapped?A: These species are known to be endangered or vunerable according to Singapore Red Data Book

Heritiera littoralis (dungun)

Picture courtesy of Ria Tan from Wild Singapore

Ceriops tagal (tengar putih)

Picture courtesy of Ria Tan from Wild Singapore

Ceriops zippelana (tengar merah)

Picture courtesy of Ria Tan from Wild Singapore

Q: How about mapping the surface elevation? 90% completed.A: Here’s the DEM with the location of trees mapped overlaid on the DEM. 4754 elevation points were taken to produce the DEM.

DEM of Mandai mangroves and the locations of mapped trees in and outside transects

Q: How about distribution of tree species vs. surface elevation gradient?

Certain tree species were found at lower elevations e.g. Sonneratia alba and Rhizophora apiculata. At highest elevations, Excoecaria agallocha and Lumnitzera racemosa were foundThere was alot overlapping of distributions across the surface elevation gradient for many species.

Grouping of species according to pair-wise distribution of surface elevation range tests. Four groups (in blue box groupings) are distributed across an surface elevation gradient. Alternatively, overlapping Bruguiera gymnorrhiza would provide a standalone Avicennia alba grouping and a larger group consisting of A. rumphiana, A. officinalis and B. cylindrica.


Q: So what can I conclude about my results?

“Mangrove zonation” most probably does not exist in Mandai. Such observation could be explained by its history of human and natural disturbances. Perhaps,  non-pristine mangrove sites such as Mandai (any site outside Mandai) may not show any form of mangrove zonation.

Q: So, what now?

More mapping is needed to certify the preliminary results since there is  an estimated 70% of mangroves trees left to mapped in Mandai!


For those who are interested to help me with my project, please click  on the following weblink and fill up the form! Thanks!



New Record of Mangrove Crab From Singapore

Hoo-ray! NUS Honours Student in Life Sciences,  Lee Bee Yan and Director of Raffles Museum of Biodiversity Research, Prof. Peter Ng have identified a new record of a pilumnid (hairy crab) mangrove crab  (Heteropilumnus  sasekumari) found in the mangroves of Singapore! Another concrete reason to conserve mangroves of Singapore-there maybe more new species of mangrove animals and plants!

Read more about this discovery in Nature of Singapore

Ecological Mangrove Rehabilitation Seminar by Ben Brown

On Friday (2nd February 2012), mangrove enthusiasts in Singapore gathered in Earth Lab, Department of Geography, National University of Singapore to attend Benjamin “Ben” Brown’s talk titled “Ecological mangrove rehabilitation – principles and case studies from Florida and Indonesia”.  The talk was hosted by Prof. Dan Friess a.k.a. Mangrove Man himself.

Introducing Dr. Ben Brown!

The audience (full house, by the way!) enthralled by Ben's seminar

Who is Ben Brown? Here is a brief introduction of Ben- he is  the Director of Mangrove Action Project (MAP) Indonesia. Hailing from Ann Arbor,Michigan,  Brown has been involved in coastal environmental education and community awareness for almost 20 years. Read more about  Ben here.

What is Mangrove Action Project (MAP)? It is a non-governmental organization which focuses on  conservation  and restoration of  mangrove forest (and other coastal ecoystems) worldwide while promoting community-based sustainable management of mangroves. MAP has several  regional offices in the U.S. and in some Asian countries, of which Ben is heading its regional office in Indonesia.

Ben telling the audience about programmes carried out of MAP Indonesia

The overall message of Ben’s seminar was to highlight the importance of understanding the ecology of mangrove establishment and mangrove geomorphology prior to mangrove restoration for  successful and cost-effective restoration of mangroves.

Here below are some highlights of the seminar:

Mangroves are losing out to human kind

They are being destroyed for multiple purposes mainly unsustainable developments including shrimp aquaculture (shrimp ponds), charcoal production and logging, oil exploration and extraction, tourism and urbanization and urban expansion. Shrimp aquaculture is the biggest threat to mangroves of Indonesia.

Blocking water bodies = mangrove death!

Mangrove death may occur when nearby mangrove areas are altered without the knowledge of hydrology, especially modification of tidal creeks or water bodies that support the vegetation area. From various case studies  pointed out in the talk, the blockage or damming of creek (e.g. dykes to prevent influx of saltwater into coconut plantations or isolation of shrimp ponds) have resulted in mangrove death by exposure of  hypersaline water (no input of freshwater) or erosion (loss of sedimentation input). MAP reinstates the flow of water i.e. the connectivity of freshwater and saltwater inputs in mangroves by drilling holes through the man-made dykes. Hydrology reinstalled!

Natural regeneration of mangroves seen after solving hydrological issues of a mangrove

Mangroves can be uplifted by the tsunami, if not destroyed!

Even mangroves may not survive from after-effects of a tsunami. Indian Ocean Tsunami in Year 2004 raised up elevation of coral reefs and mangrove areas in Acheh. This has lead to massive coral death (and bleaching) due to prolonged emersion/exposure to air and drying out of mangroves. Mangroves at higher elevations are now competing with terrestrial forests for space and survival. Even if the mangroves survive, their propagules will not be dispersed (due to little the no-longer existence of sea flooding for dispersal) nor established (due to the change in soil properties for e.g. soil type, temperature and soil moisture).

Mangrove survival depends on its flooding properties

-Mangroves establishment is highly dependent on frequency of its  inundation/flooding and inundation range, which in turn dependent on surface elevation (high, medium and low elevations).

Ben showing the inundation frequencies play a vital role in determining a mangrove survivability

-The knowledge of the surface elevation allow distinction of inundation zones within a mangrove, of which, mangrove species are selective towards specific inundation zones which they thrive in. For e.g., Avicennia spp. are pioneer species in Southeast Asian mangroves and would normally be found on low surface elevation/more frequently inundated zones.

Hmmh,  where I shall plant mangroves?

Ben also highlighted another mistake of other mangrove restoration projects. Most mangroves do not grow at low elevation i.e. below mean sea level. Although mangroves have the ability to tolerate lack of oxygen, prolonged lengths of water immersion (which may lead to accumulation of hydrogen sulfide toxicity) does not bode well for them, particular that of seedlings (young plants). Hence mangrove replanting  by other parties are often not successful as seedlings are planted at low elevation mangrove sites.

Planting Grass for Mangrove Restoration?

-Mangrove restoration at certain areas can be carried out with grass on bare grounds to assist natural mangrove recruitment when mangrove propagules are trapped by the grass. The grass will be removed eventually after the seedlings have grown.

Mangrove Restoration without replanting them. How?

-MAP approaches  mangrove restoration through  basic natural processes i.e. termed ecological mangrove restoration (EMR). Therefore,  contrary  to other mangrove restoration organizations, MAP does not implement nor advocate mangrove planting; the organization believes in natural establishment of mangroves from existing mangrove plants in a degraded site.

Therefore, it focuses to revert the modified topography and hydrology of a site to its natural conditions (prior to the modification) which in turn allows natural regrowth or succession of mangrove plants. This approach is more cost-saving (because mangrove propagules do not come cheap!) and  growth rate of planted mangroves  is slower than natural growth itself.

-A more detailed step-wise approach on EMR are simplified as below :-

    1. Understand the biology i.e. characteristics of  individual mangrove (tree or shrub) species and  their communities, especially that of reproduction patterns, distribution ranges and  seedling establishment;
    2. Understand the normal hydrology that controls the distribution and successful establishment and growth of targeted mangrove species;
    3. Assess the severity of the modified of the mangrove and  the causes that currently prevent natural regrowth of mangrove species i.e. natural secondary succession;
    4. Select appropriate restoration areas through application of Steps 1-3, that are both likely to succeed in rehabilitating a forest ecosystem and are cost effective. This includes recruitment of  labor to carry out the projects, including adequate monitoring of their progress and resolving land ownership/use issues necessary for ensuring long-term access to and conservation of the site;
    5. Design the restoration program and utilize natural volunteer mangrove recruitment for natural plant establishment and long-term assessment for the mangrove site.

    Read in more detail about EMR here.

Communities awareness and involvement in mangrove restoration and conservation

Ben ended his talk with by mentioning several approaches that have been conducted by MAP to raise awareness within the local community and get them involved in mangrove restoration, monitoring and conservation projects . In Indonesia, there is a need to convince locals to stop conversion of mangroves into shrimp ponds since they are regarded as short-term cash cows. Therefore, incentives are given to locals to convince them on keeping mangroves for the more valuable profits gained from its ecosystem services. Mangrove-based products and recipes are being introduced to locals.

Several examples of mangrove products made from mangrove plants

Woman groups are also  involved in monitoring mangrove restoration sites.

....including Acanthus (sea holly) tea!!!

After the talk, there were multiple discussions/chatter on-going among the mangrove enthusiasts from different walks of life-all hyped for future mangrove plans in Singapore!

Ria Tan (Wild Singapore & Intertidal Queen) engaging in a conservation with two NParks mangrove officers

Jeffrey Low(NParks), Huiying (Nparks), Wei Kit the Mangrove Warrior and Dr. Jean Yong having a great discussion on mangroves!

Sivasothi a.k.a. Otterman talking to Dr. Ben Brown after the inspiring talk!

Kudos to Mangrove Man for being a great host!

In summary, the seminar was very informative and the multiple case studies in the seminar highlighted the efforts made by Ben, Iona and his MAP team. Kudos to MAP Indonesia! Terima Kasih (Thank you in Indonesian and Malay) Ben for the your inspiring talk and best wishes for MAP Indonesia from Mangrove Action Squad!

Preliminary result of Mandai mapping project

After a few months of hard work in Mandai mangroves, Mangrove Action Squad is glad to report some preliminary of Mangrove Apprentice a.k.a. Rick’s project. After having mapped about 600 trees,  the distribution of tree species near Sungei Mandai Kechil can be seen in the figure below! That’s quite awesome, isn’t?

Perhaps this is a sign of species zonation in Mandai? There needs to be more work done to conclude the observation?

Well, there’s still a long way more to complete the vegetation survey. The ultimate goal: to map every SINGLE tree in Mandai. Perhaps another 10,000 more trees to be mapped?  For now, Rick will be mapping trees within specific 10-metre wide transects perpendicular  to the shoreline in Mandai to  accommodate the timeline for his thesis.

The transects are 200m apart, namely denoted A1 to A4. The fifth transect (orange transect line but not labelled in the figured above) is the first transect to be completed, as shown the earlier figure.  The yellow color pins denote the benchmarks for total station.

Estimated date to complete mapping the vegetation in transects : End of February 2012.

Will he be able to complete this in time?….. We’ll see and we are looking forward to see the outcome of this cool project!

Keep up your good work, Rick!

Current Research Project: Mapping Vegetation of Mandai Mangroves

On 24th September 2011, MAS was lucky to be part of Biodiversity of Singapore Symposium III (2011) and Mangrove Surveyor a.k.a Rick was given the golden opportunity to conduct a poster presentation of his ongoing Honours project titled ‘Investigation of Elevation-Vegetation Processes in Mandai Mangroves’. Ria Tan has his project all figured out, check this out!

Q: So what is  his project about?

A: He is mapping the soil elevation of the  Mandai mangrove (i.e. slope of soil surface of the mangrove) and vegetation i.e. trees of the mangrove.

Q: where is  this Mandai  mangrove?

A:Well, it’s located near  Woodlands Checkpoint. However, public may not access the mangrove freely as it is a restricted site only bound for researchers with permit!

Q: So how does he map the mangrove’s elevation and vegetation?

A: He uses a surveying equipment called the total station (similiar to that of a camera) on a tripod which shoots lasers towards the prism head of a surveying pole held vertically to the ground.Each survey point that is measures the location and elevation of the point!

Total Station used for surveying

Overall setup for the total station

Q: Ahh…sounds ‘cheem’! (difficult in Singlish) So does every survey point measure the elevation of the soil? How about tree mapping?

A: Nah, not at all. The principle behind the surveying equipment is quite easy. He shall explain to you in more detail when you choose to join him for his surveys

Q: How about mapping trees? How does he do it?

A:Mapping trees consist of :-

(1)Measuring diameters of trees

Ria Tan of Wild Singapore fame helping Rick with his surveys.

3)Getting coordinates of trees

Wei 'Win-Win' Kit holds the pole with prism where it is grounded to the approximate location of the a measured tree

Dr. Balaji using the total station to capture the location of tree

Q: So how many trees will Rick map?

A:  At least 3000 trees and he has to identify each of them. Thankfully Dr. Jean Yong’s Comparative Guide to the SIngapore Mangroves helps him alot!

Q:So why should I volunteer to help in this project?

A: Many reasons actually but Rick gives three main reasons!

(1) Fun in the mud! If it is your first time stepping into a mangrove, it’s quite surreal!

Muddy fun time at Mandai Besar River!

2) Amazing fauna to look out for in Mandai

Some fauna found in Mandai mangrove

3) View of  Johor from way up here (Nope, you don’t to climb trees, just kidding) The view from Mandai is breath-taking; you have to be there to see it for yourself

Rick climbing a Rhizophora tree!

View of Johor Bahru and Johor Straits from Mandai Mangrove

Kindly email Rick at if you’re interested to know more about this project and help him with his project.