SINGAPORE — Work to restore the shoreline of Pulau Ubin - announced as part of the Ubin Project in 2014 - is set to begin next year, with completion slated for early 2020.
As part of shoreline restoration efforts, a coastal boardwalk, which will span about 500m in length and partly extend into the sea, will also be built. From the boardwalk, visitors will have views of the island's coastal mangroves and hills.
Providing an update on Sunday (May 22), the National Parks Board (NParks) said feasibility studies for shoreline restoration efforts on the island, which began in the middle of last year, wrapped up earlier this month.
Pulau Ubin's shoreline, particularly at Noordin Beach in the island's north, had been observed to be eroding, threatening coastal and mangrove habitats and exposing the foundations of old buildings, among other things.
Changes in wave conditions, due in part to ship wakes, as well as land-use change, NParks said, were found to be among the principal causes of the erosion.
Following modelling studies by external consultants, the possible measures identified to tackle the erosion include constructing headlands with armour rocks.
The headlands, to be spaced 200m apart and with sand nourishment between them, will serve as control points, enabling a crenulated-shaped beach to develop.
Noordin Beach, a popular camping site forced to shut in 2013 because of severe erosion, will reopen to the public for outdoor recreation when the restoration works are completed.
Also unveiled on Sunday was a design for new otter dens, or "holts", as part of species recovery efforts for the oriental small-clawed otter - the first time such spaces are being built for the critically endangered species endemic to Pulau Ubin and Pulau Tekong.
Two such otter holts will be erected at Noordin Beach and near the Sensory Trail ponds on the island by year-end to monitor and study the behaviour of the mammals.
Species recovery efforts are also underway for bats on the island, with a bat house established near Noordin Beach earlier in the year and 30 bat boxes being installed progressively across the island.
Senior Minister of State (Home Affairs and National Development) Desmond Lee, who joined the community in planting mangrove saplings on Sunday morning at the island's mangrove arboretum, said more must be done to protect the rich biodiversity on Pulau Ubin.
But the authorities cannot do this alone, he noted. "There will certainly be more avenues for community participation with initiatives such as the orchid conservation project and mangrove restoration programme.
"I hope that many more Singaporeans will join us in our endeavour to conserve the many living organisms that exist alongside us," he said.
Pulau Ubin to have coastal boardwalk after shoreline restored
There have also been efforts to protect critically endangered species unique to the island, like the Oriental Small-clawed Otter.
Alice Chia Channel NewsAsia 22 May 16;
SINGAPORE: Pulau Ubin will boast a new coastal boardwalk for the public once shoreline restoration works - set to begin in 2017 - are complete, said Senior Minister of State for National Development Desmond Lee on the island on Sunday (May 22).
About 100 members of the public gathered at Pulau Ubin on Sunday morning to plant mangrove saplings. When the mangroves mature, the public can get to view them from the boardwalk that will be built as part of efforts to restore the island's shoreline.
Said Mr Lee: "In the past year, NParks has worked hard to restore Ubin's shoreline. We started feasibility studies in mid-2015 and shoreline restoration work will commence soon. It will be a major project.
“At the same time, we will provide a coastal boardwalk which will extend into the sea in the north of Ubin, so that visitors can enjoy vistas of the sea and coastal forests.”
The shoreline on two beaches - Noordin and Mamam Beach - will be extended from 2017. In time to come, Noordin Beach will be reopened for outdoor recreational use, Mr Lee added.
There have also been efforts to protect critically endangered species unique to the island, like the Oriental Small-clawed Otter. New otter holds or dens have been designed to monitor and study their behaviour.
About 800 orchids of 15 different species are also being propagated and reintroduced across the island, as part of the NParks Orchid Conservation Programme.
More activities that showcase the biodiversity on Pulau Ubin's shores will be held on Ubin Day on Jun 4.
- CNA/xk
Plans to protect Pulau Ubin’s rich biodiversity in the works
KENNETH CHENG Today Online 23 May 16;
SINGAPORE — A rejuvenated shoreline, a new coastal boardwalk and spaces for critically endangered animal species — such as otter dens — are in the works for Pulau Ubin, in an effort to protect the island’s rich biodiversity.
Works to restore the island’s shoreline — in particular the northern shoreline — are expected to begin next year and conclude by early 2020, the National Parks Board (NParks) announced on Sunday (May 22). A tender will be called soon for this purpose.
Plans to restore the shoreline were announced in 2014 as part of the Ubin Project, an ongoing effort to gather suggestions on enhancing its natural environment and protecting its rustic charm. Pulau Ubin’s shoreline, particularly at Noordin Beach in the island’s north, had been observed to be eroding, threatening coastal and mangrove habitats and exposing the foundations of old buildings, among other things. Erosion was also behind the closure of Noordin Beach, a popular camping site, in 2013.
Feasibility studies on shoreline restoration work, which took place over a year and wrapped earlier this month, found that changes in wave conditions, due in part to wakes generated by the movement of ships, as well as land-use change, were among the key causes of the erosion.
Following modelling studies by external consultants, the construction of headlands with armour rocks has been identified as a possible measure to restore the island’s northern shoreline, particularly at the Noordin and Mamam beaches. The headlands, spaced 200m apart from one another and with sand nourishment between them, will serve as control points, allowing for a curved beach to form.
In addition, mangrove restoration measures will be deployed in tandem by filling undercuts chiselled by waves with substrate in biodegradable sacks — such as soil — alongside rocks at the toe, to shield the shoreline from further erosion by the waves. Wooden poles will also be erected to break up the energy of the waves, creating an environment conducive to the growth of mangroves.
These measures, NParks said, have been “assessed to be most suitable in protecting and rehabilitating the northern shoreline with minimal impact to the surrounding”.
A coastal boardwalk, which will span about 500m in length and partly extend into the sea, will also be built as part of shoreline restoration efforts. From the boardwalk, visitors will have views of the island’s coastal mangroves and hills. Noordin Beach will reopen to the public for outdoor recreation when the restoration works are completed.
Also unveiled on Sunday was a design for new otter dens, or “holts”, as part of species-recovery efforts for the oriental small-clawed otter.
It is the first time such spaces are being built for the critically endangered species endemic to Pulau Ubin and Pulau Tekong.
Two such otter holts will be erected at Noordin Beach and near the Sensory Trail ponds on the island by year-end to monitor and study the behaviour of the mammals. Species-recovery efforts are also underway for bats on the island, with two bat houses set up near Noordin Beach and at Bukit Belukar earlier this year and 30 bat boxes being installed progressively across the island.
Senior Minister of State (Home Affairs and National Development) Desmond Lee, who joined the community in planting mangrove saplings at the Ubin Living Lab’s mangrove arboretum on Sunday, said more must be done to protect Pulau Ubin’s rich biodiversity.
But the authorities cannot do this alone, he noted. “There will certainly be more avenues for community participation … I hope that many more Singaporeans will join us in our endeavour to conserve the many living organisms that exist alongside us,” he said.
Conservation expert Ho Hua Chew, vice-chair of the Nature Society (Singapore)’s conservation committee, said the shoreline restoration works were “necessary”.
Dr Ho pointed to the importance of breaking up wave action in preventing further erosion, and was confident that NParks had studied the shoreline and wave movements and considered its course of action carefully.
On the other hand, Mr Ben Lee, founder of nature conservation group Nature Trekker, thought the plan to erect a boardwalk unnecessary. A boardwalk will attract scores to the island’s north, disturbing the tranquility of the area, he said, adding that its development would also have an impact on the environment. “To me, Ubin is to be left as natural as possible — (that) is the best,” Mr Lee said.
Meanwhile, an upcoming community event to celebrate all things Ubin — Ubin Day on June 4 — will include guided walks and craft workshops showcasing the island’s biodiversity. Author Neil Humphreys will also be reading from his latest children’s book on Pulau Ubin, in a storytelling session for children below 12.
Pulau Ubin to get a coastal boardwalk
Melissa Lin, MyPaper AsiaOne 23 May 16;
MORE will be done to protect Pulau Ubin's flora and fauna, including plans to restore its northern shoreline, build a coastal boardwalk and support the recovery of endangered plants and animals.
Announcing these initiatives yesterday at Pulau Ubin, Senior Minister of State for Home Affairs and National Development Desmond Lee said more must be done to protect the rich biodiversity teeming on the island.
Noting that it has more than 720 native plant species and over 500 animal species, including some not found on mainland Singapore, he added: "This is remarkable but we must do more.
"We have plans to restore Ubin's eroding shoreline, which will serve as a base for more of Pulau Ubin's flora and fauna to be restored in the near future."
Shoreline restoration was one of the earliest priorities for The Ubin Project, announced in 2014 to generate ideas from the public on how to retain the island's rustic charm.
Erosion has badly affected about 40m of northern Ubin, threatening critically endangered species like the Eye of the Crocodile tree and leading to the closure of Noordin Beach - a popular camping site - in 2013 for public safety.
A year-long study, which was concluded this month by the National Parks Board (NParks), found that changes in wave conditions partly as a result of ship wakes, or waves generated by the movements of vessels, as well as changes in land use were among the key causes of erosion.
NParks has identified possible measures to restore the shoreline, such as using man-made rock structures and sand to widen the existing beaches, growing more mangroves and adding wooden poles along the shoreline to mitigate the impact of waves.
NParks will call a tender and works are expected to start next year and end by 2020.
An impact assessment will be done, said NParks' director for Pulau Ubin, Robert Teo.
"Until we call a tender, we won't be sure how much (the work) is going to cost. It depends on the magnitude of the designs and the amount of work that's going to be done," he added.
A coastal boardwalk of about 500m, part of which will extend into the sea, will be built at Noordin Beach, which will reopen when restoration works are completed. From the boardwalk, visitors can view coastal mangroves and hills.
Yesterday, NParks also unveiled a design for new otter holts - which are dens for the critically endangered Oriental Small-clawed Otter. By the end of this year, two holts will be installed on the island which will allow researchers to monitor and study their behaviour.
Other species' recovery efforts include installing 30 bat boxes across the island for bats to roost, and reintroducing endangered native orchids to parts of the island.
At the event to mark the International Day for Biological Diversity, which was yesterday, Mr Lee joined more than a hundred participants to plant 100 saplings at the mangrove arboretum in the Ubin Living Lab.
Among them were executive manager Sean Lam, 47, and his wife and son.
He said: "This is one of the last places in built-up Singapore where you can enjoy such nature. Without the mangroves, the soil will be eroded and the next generation, they won't have anything to see."
Rare animals and plants in Pulau Ubin you won't get to see in Singapore
AsiaOne 23 May 16;
The next time you visit Pulau Ubin, take a closer peek at your surroundings, as it might reveal treasures of nature that are more unique and interesting than a cursory glance of the coastal and old kampong charms of the island.
You might have spotted wild boars foraging for food near bicycles parked by visitors, aquatic flowers blooming in ponds and big spiders trapping their victims in gossamer webs.
But do you know that the island off the Changi coast is is home to more than 720 native plant species and over 300 species of animals? What makes Pulau Ubin more special is that some of these species are found only on the island and not on mainland Singapore.
If you're thinking of taking a boat trip to the island again, do look out for these fascinating animals, insects and plants that have been clinging on for survival on the most endangered list. Bring along a pair of binoculars and marvel at close range.
Ashy Roundleaf Bat (Hipposideros cineraceus)
Two colonies of this critically endangered bats have been made abandoned buildings in Pulau Ubin their homes. Although found in South Asia and Southeast Asia, it has never been spotted on the mainland.
Lesser False Vampire (Megaderma spasma)
In Singapore, this bat (above) is found only on Pulau Ubin and Pulau Tekong. Recently, Ubin has become popular with this species as several colonies have been found occupying disused structures. It feeds primarily on insects. No, it does not go after your blood.
Oriental Small-clawed Otter (Aonyx cinerea)
Nine sightings of this otter (below) on Pulau Ubin have been recorded over the past 16 years. No recent sightings on the mainland.
Dwarf Crow (Euploea tulliolus ledereri)
Believed to be extinct in Singapore but rediscovered on Pulau Ubin in 2002, this butterfly (below, left) flutters quite lazily, usually drawn to the hairy Indian Heliotrope plant (Heliotropium indicum).
Common Jay (Graphium doson evemonides)
Last spotted on the mainland in 2006, it was found again on Pulau Ubin in 2005. The Common Jay (below, right) is constantly on the move, flitting from one flower to another to feed on nectar.
Greater mouse-deer (Tragulus napu)
Thought to be extinct on the mainland, there is a sizable population on Ubin. It inhabits forested areas, and emerges at night to forage for fallen fruits, leaves, grasses and aquatic plants.
Rare trees and orchids
Collared fig (Ficus crassiramea)
This critically endangered tree can be found in Pulau Tekong and Pulau Ubin only. There are a few specimens of this 'killer' tree on Ubin, including one acknowledged officially as a Heritage Tree near Ketam Mountain Bike Park. The 'strangling fig' grows from a seed left by animals like birds at the top of a tree. From here, it fans out its roots downwards till it encircles the host tree's trunk. In many cases, the host tree is finally "strangled" to death after many years.
Eye of the Crocodile (Bruguiera hainesii)
Critically endangered, it is one of the rarest mangrove species in the world with only about 200 mature trees left. Eleven including two on Ubin are found in Singapore. One tree was found in the southern coast of Ubin, while another was discovered on Noordin Beach in 2005. National Parks (NParks) has started a programme to collect and plant young seedlings to increase the population.
Ficus stricta
Another rare species of the strangling fig, it was listed as native to Singapore only in 2012, after the first specimen was discovered in Changi. It is only known to thrive in Changi and Pulau Ubin. In the 19th century, British engineer and artist John Turnbull Thomson produced a drawing of a tree in 1850, which is thought to be the same one found near the mouth of Sungei Pulau Ubin, in 2002. Listed as a Heritage Tree, it is believed to be more than 160 years old. It bears fruit only after intervals of more than six years. Oriental Pied Hornbills and Green Imperial Pigeons have been spotted feeding on the figs.
Hybrid stilt mangrove-happy face (Rhizophora X lamarckii)
In 2011, an NParks staff chanced upon this naturally-occurring mangrove hybrid of of the Rhizophora apiculata and Rhizophora stylosa, creating a new record here. So far, five trees have been found at the Sungei Jelutong and Jalan Noordin mangrove.
Marsh Pulai (Alstonia pnuematophora)
It stands out from other Pulai trees because of its 'breathing' roots. Found mainly in the central forests on the mainland, a few trees flourish on Pulau Ubin.
Jamba (Neuwiedia veratrifolia)
Found in lowland forests, this critically endangered orchid (above) produces long clusters of yellow flowers. Grown on soil, the Jamba will see its population multiply as plantlets at one site have been transplanted to two other areas on Ubin.
Pterospermum diversifolium
This tree species was first collected by Henry Ridley, former director of the Singapore Botanic Gardens. It was thought to be extinct, but was found in Pulau Ubin in 2013. Currently, fewer than 50 mature trees are seen in Singapore.
Sheath-covered Spathe Robiquetia (Robiquetia spathulata)
This critically endangered orchid was recorded only once in Singapore by Henry Ridley, who collected it near the Botanic Gardens. It was only in 2006 that a single plant was rediscovered in Pulau Ubin. Through tissue culture, the species has been successfully propagated and reintroduced to other parts of Pulau Ubin, as well as mainland Singapore.
Thrixspermum amplexicaule
You would be lucky to catch a glimpse of this rare pale lilac orchid as its blooms last for only a day. The semi-aquatic orchid was found at one site on Ubin, but it has been successfully propagated and reintroduced to other sites on the island since 2010. Still regarded as critically endangered.
Utania nervosa
Discovered at Ubin's Chek Jawa in 1997, this small tree was named as a new species called Utania racemosa in 2014. A common tree on Pulau Ubin and Pulau Tekong, it is also found in south-east Johor. It has large, leathery leaves shading clusters of white flowers with very short stalks.
Community participates in efforts to enhance Pulau Ubin’s natural heritage as part of the International Day for Biological Diversity celebrations on island
NParks 22 May 16;
* New shoreline restoration measures to be carried out at Noordin Beach
* New coastal boardwalk for public to be built
Singapore, 22 May 2016 — Members of the community today gathered at Pulau Ubin to participate in reforestation and species recovery efforts as part of the International Day for Biological Diversity celebrations on the island. Senior Minister of State for Home Affairs and National Development, Desmond Lee, together with over 100 members of the community, planted mangrove saplings at the Ubin Living Lab’s new mangrove arboretum to help reforest the island’s mangroves. In addition, SMS Lee gave an update on the progress for some of species recovery efforts initiated by the Friends of Ubin Network (FUN) as part of The Ubin Project. SMS Lee also announced that the National Parks Board (NParks) will begin physical works for shoreline restoration at Noordin Beach in 2017. As part of restoration works, a new coastal boardwalk will be built for the public to appreciate views of the sea and coastal forests.
SMS Lee said, “Singapore may be small, but we are teeming with biodiversity. Just in Pulau Ubin alone, we have over 720 native plant species and over 500 animal species, including some not found on mainland Singapore. This is remarkable, but we must do more. We have plans to restore Ubin’s eroding shoreline, which will serve as a base for more of Pulau Ubin’s flora and fauna to be restored in the near future.
But we cannot do this alone. As we gather to mark the International Day for Biological Diversity on Pulau Ubin today, we also celebrate the strong partnership with the community that has allowed us to achieve progress in our species recovery efforts for the unique biodiversity on the island. There will certainly be more avenues for community participation with initiatives, such as the orchid conservation project and mangrove restoration programme. I hope that many more Singaporeans will join us in our endeavour to conserve the many living organisms that exist alongside us.”
International Day for Biological Diversity celebrations on Pulau Ubin
The International Day for Biological Diversity is held yearly worldwide on 22 May to increase global awareness of biodiversity issues. As part of the celebrations on Pulau Ubin, the public could attend talks and workshops about the island’s biodiversity. In addition, the community, including FUN members, planted 100 trees at the mangrove arboretum in the Ubin Living Lab. In the long run, these trees would supplement restoration efforts across the island. Mangrove forests are vital to the coastal zone in Pulau Ubin as they protect the shoreline from erosion. Restoring mangrove ecosystems would in turn conserve the habitats for native biodiversity like fiddler crabs and mudskippers. The activities organised today were part of NParks’ efforts to raise awareness and deepen public appreciation for native biodiversity on the island, as well as share how the public can play a part to sustain our natural heritage for future generations.
Shoreline restoration works at Noordin Beach – new boardwalk to be built for public
Shoreline restoration was one of the earliest priorities for The Ubin Project when it was first announced in 2014. The island’s shoreline was observed to be eroding, in particular the northern part of the island at Noordin Beach, along the mangroves and low cliff faces. This has led to a loss of coastal and mangrove habitats. Furthermore, the erosion exposed the foundations of old buildings and undermined the structural integrity of two shelters. The severity of the erosion led to the closure of Noordin Beach, a popular camping site, in 2013 for public safety.
Feasibility studies for shoreline restoration efforts began in mid-2015 and concluded in May 2016. Some of the key causes of erosion were identified to be changes in wave conditions partly due to ship wakes as well as changes in land use.
Consultants have carried out modelling studies to assess various measures. The use of headlands as well as the addition of sand to extend the shoreline seaward has been identified as a possible measure to restore the island’s northern shoreline in areas including Noordin Beach and Mamam Beach. This will be supplemented by mangrove restoration efforts. The headlands will also provide opportunities to restore beach vegetation in the area.
When works are completed, Noordin Beach will be reopened for visitors to engage in nature-based recreation. In addition, a coastal boardwalk of about 500 m long would be integrated into the restoration works, part of which will extend into the sea, affording visitors views of the island’s coastal mangroves and hills. Furthermore, restoration of Pulau Ubin’s shoreline will lay the foundations for future phases of habitat enhancement and species recovery projects. See Factsheet A for more details on shoreline restoration measures.
Species recovery efforts under The Ubin Project – design for otter holts unveiled
NParks unveiled a design for new otter holts or dens to be used in species recovery efforts for the Oriental Small-clawed Otter (Aonyx cinerea). As part of overall species recovery plans mapped out under The Ubin Project, these holts are being constructed for the critically endangered native otter for the first time in Singapore. By end-2016, two holts will be installed at Noordin Beach and near the Sensory Trail ponds to monitor and study otter behaviour.
Much of Pulau Ubin’s rustic charm lies in the unique native biodiversity which cannot be found on the mainland. The native Sheath-Covered Spathe Robiquetia (Robiquetia spathulata) orchid was previously thought to be extirpated until it was rediscovered in 2006 by NParks staff. Together with other endangered native orchids like the Jamba (Neuwiedia veratrifolia) and Thrixspermum amplexicaule, these are among some 800 orchids from 15 distinct species that are currently being propagated and reintroduced across Pulau Ubin as part of the NParks Orchid Conservation Programme.
Other species recovery efforts include installing 30 bat boxes of six different designs across Pulau Ubin for insectivorous bats to roost. One of these boxes has been installed at the Ubin Living Lab. The bat recovery programme aims to increase the diversity of bats on Pulau Ubin, and assist in the recovery of uncommon species. Part of this programme will complement the forthcoming shoreline restoration works as a bat house has been set up near Noordin Beach in early 2016.
Examples of biodiversity found on Pulau Ubin and not on mainland Singapore are in Factsheet B.
Restoring Ubin Mangroves (RUM)
Amongst those who planted at the mangrove arboretum today were RUM members. Conceived during one of the FUN sessions, the RUM initiative serves to restore mangrove forests through a science-based approach complemented by community outreach efforts. The Ecological Mangrove Restoration (EMR) approach will be applied based on science-informed methods, taking into consideration site characteristics and environmental factors to regenerate mangrove populations. Mangrove restoration measures are being considered for the mangroves along Sungei Besar, Sungei Mamam and Sungei Jelutong. Some of these mangrove restoration efforts may also be adapted to protect the island’s shorelines where they have been observed to be eroding. More details of the EMR can be found in Factsheet C.
RUM Members include the Marine Conservation Group of the Nature Society (Singapore), Gamefish and Aquatic Restoration Society (GARS), Eastern fish farmers at Pulau Ubin, the Mangrove Lab (Department of Geography, National University of Singapore) and founder of wildSingapore, Ms Ria Tan. This is coordinated as part of NParks' habitat restoration and reforestation programme on the island.
Members of the public who are interested to participate in RUM can sign up at http://rum-initiative.blogspot.sg/.
Public activities on Pulau Ubin
Members of the public who wish to learn more about Pulau Ubin’s cultural and natural legacy may sign up for activities under Pesta Ubin, organised by volunteers and FUN members, running from 14 May to 12 June. Details can be found on the Pesta Ubin website at http://pestaubin2016.blogspot.sg/.
The upcoming Ubin Day on 4 June offers more opportunities to participate in events centred on Pulau Ubin’s heritage. Activities include guided walks and craft workshops which showcase the biodiversity on Pulau Ubin’s shores. Children below the age of 12 can also join in a storytelling by bestselling author Neil Humphreys, who will be sharing from his latest children’s book on Pulau Ubin. Please visit www.nparks.gov.sg/ubin for more information and to register for activities.
Factsheet A - Details on shoreline restoration measures
Factsheet B - Examples of biodiversity found on Pulau Ubin and not on mainland Singapore
Factsheet C - Ecological Mangrove Restoration (EMR)
Factsheet D - Information of tree planted by Senior Minister of State, Desmond Lee
MEDIA FACTSHEET A
Shoreline Restoration Works at Noordin Beach
Pulau Ubin’s shoreline was observed to be eroding, in particular at the northern part of the island at Noordin Beach, along the mangroves and low cliff faces. This has led to a loss of coastal and mangrove habitats. The southern coastline was observed to be generally stable with the exception of a few areas.
Feasibility studies for shoreline restoration efforts began in mid-2015 and concluded in May 2016. These were the steps taken to determine the causes and explore possible mitigating measures to arrest the erosion.
1. Data Collection and Site Assessment: Existing information such as satellite images, hydrodynamics, ecological and land use data was reviewed. A series of topographical, hydrographical, mangroves, sediment and vessel traffic surveys was also conducted. These allowed us to understand the existing conditions at Pulau Ubin and determine the extent of erosion and impact on ecological habitats along the entire shoreline of the island.
2. Coastal Dynamic Assessment and Identification of Erosion: Hydrodynamic and wave modelling was conducted to assess causes and effects of erosion around the island. Based on the modelling results, critically eroded areas of importance were identified for protection/restoration. This included Noordin Beach in the north of the island.
3. Identification and Evaluation of Mitigating and Restoration Measures: Based on the identified causes of erosion and affected areas, potential restoration and mitigation measures were developed and tested via modelling to assess their effectiveness.
4. Shoreline Stabilisation Plan: Measures that have been developed will be consolidated in a holistic plan for the monitoring and management of the coastline in the long term. This plan encompasses monitoring and management measures for target areas and the rest of the coastline.
Some of the possible causes of erosion which were identified include:
• Changes in land use – Aquaculture ponds which are no longer in use have led to breaches in the surrounding bunds over time. The disuse of the ponds’ tidal gates has also resulted in uncontrolled inflow and outflow of water from the ponds. This has increased the volume of water leaving the ponds at ebb tide, causing erosion at the river mouths and mangrove habitats at Sungei Besar and Sungei Mamam.
• Impacts from waves and ship wakes – The average environmental wave condition at Pulau Ubin is mild. However, wakes generated by vessel movements at certain sections of the shoreline with high vessel traffic cause higher wave energy, removing sediment away from the foreshore, resulting in the shoreline retreating. Wave energy is greatest in the east (Chek Jawa Wetlands), with its force decreasing westward along the shoreline. Vessel wake energy appears to be most prevalent in the narrow strait between Pulau Ubin and Johor, especially at the northwestern end of the island.
Consultants have carried out modelling studies to assess which measures are likely to be effective. Based on the identified causes of erosion, possible measures which were considered to restore the island’s northern shoreline include man-made hard structures such as groynes, detached breakwaters or headlands as well as the addition of sand to widen the existing beach.
• Headlands coupled with Beach Nourishment
The headlands will be constructed with armour rocks and spaced 200 m apart with nourishing of sand at the shoreline in between. With the headlands acting as control points, a crenulated-shaped beach can thus be formed, creating a more advanced shoreline than the current position.
Based on model testing of the different hard engineering measures, this, coupled with mangrove protection measures, has been assessed to be most suitable in protecting and rehabilitating the northern shoreline with minimal impacts to the surrounding.
Layout of headlands (left), example of headlands at East Coast Park (right) Photo credit: Surbana Jurong
• Mangrove Restoration Measures
Mangrove restoration measures which consist of mangrove toe protection and rehabilitation were also considered for the eroded mangrove shorelines at Sungei Besar, Sungei Mamam and Sungei Jelutong to stabilise the shoreline and prevent further loss of mangrove habitats.
The placement of suitable substrate to fill the mangrove undercuts, as well as rocks along the toe, helps to protect the shoreline from further wave actions. The wooden poles form a semi-permeable wave barrier to attenuate the wave actions and
encourage sediment accumulation in front of the toe protection, creating a conducive environment for mangrove growth. Such mangrove restoration measures have been tested in Sungei Buloh Wetland Reserve and were found to be effective.
Filling in disused aquaculture ponds will help control the inflow and outflow of water through the tidal gates, thus regulating the volume of water exchanged during tidal cycles and reducing wave impact. This allows for more sediment accumulation,
which encourages mangrove growth. The new mangroves will in turn arrest erosion to prevent further loss of mangrove habitats.
Part of the works to restore Pulau Ubin’s northern shoreline will also incorporate a coastal boardwalk approximately 500 m long, part of which extends into the sea. This would allow visitors to view the island’s coastal mangroves and hills.
MEDIA FACTSHEET C
Ecological Mangrove Restoration (EMR)
Ecological mangrove restoration (EMR) is defined as “an approach to coastal wetland rehabilitation or restoration that seeks to facilitate natural regeneration in order to produce self-sustaining wetland ecosystems.”
This approach works with physical processes, especially elevation and hydrology, to improve restoration success by ensuring that the site conditions are right for the mangrove species selected. Some ways in which this can be achieved include increasing the elevation of the site and widening channels to improve hydrology, thus easing the flow of propagules from elsewhere. In allowing mangrove propagules to disperse within an area naturally, it reduces the need to manually plant propagules. This may result in a more sustainable EMR project in the long run as a steady supply of propagules from beyond the site replaces seedlings which
may be lost by waves or infestation.
The factors which will guide the selection of mangrove species for the EMR process are:
• Species-specific traits such as tolerance to flooding
• Site characteristics including elevation, height of tides etc.
• Availability of propagules in the vicinity to disperse to the target site
• Tidal flooding, which increases the landward reach of waves and currents
• Wave and current patterns
• Size of area
The steps for a successful EMR, as described by mangrove researcher, R.R. Lewis, are:
1. Understanding the species ecology (reproduction, dispersal, seedling establishment)
2. Understanding hydrological patterns determining seedling distribution and establishment
3. Assessing man-made modifications to the environment that may be preventing natural colonisation
4. Selecting the most appropriate restoration site possible, using information from Steps 1–3. Besides assessing physical and ecological parameters as above, this step also involves anticipating and resolving community issues such as land tenure and land
use, to allow long-term access to the site and the sustainability of conservation.
5. Designing the restoration site to restore appropriate hydrology and natural recruitment
6. Only actively plant propagules and seedlings if step 4 will not be successful or rapid vegetation cover is required
The EMR method has been widely adopted in many countries. Successful case studies include a community-based EMR in Tanakeke island in South Sulawesi, Indonesia. The reestablishment of the natural mangrove ecosystem yielded benefits to the local fishing
community such as greater storm protection and availability of non-timber forest products for local markets as well as subsistence use.
Found in “Ecological Mangrove Rehabilitation: A Field Manual for Practitioners” by Roy Robin Lewis II and Ben Brown, 2014.