Checking the mangroves on the Pulau Hantu seawall in Mar 2013 |
I first noticed the mangrove trees that had settled naturally on Pulau Hantu's artificial seawalls in Apr 2009. They were already well established and were probably growing there for sometime. I returned regularly since then to keep track on them.
The brown layer in the water outside the seawall are Sargassum seaweeds growing on the reefs there. |
A wide variety of mangrove trees have settled on the wall. |
Sealed wall (upper portion) versus open bouldery bottom wall. |
There are also little mangrove trees settling in the lush 'meadow' of Gelang laut (Sesuvium portulacastrum) that cover the high shore. It would be great to eventually have a little mangrove forest on Pulau Hantu!
With a mangrove forest, Pulau Hantu will then be one of the few places in Singapore where a nice range of shore ecosystems exist in a continuum as they are meant to be. Mangroves, seagrass meadows and coral reefs!
Corals growing near the seawall. |
Seagrasses growing near the seawall. |
Mangroves had also settled naturally on artificial shores near the Marina Barrage.
These photos were taken in Nov 2008. Shortly after, the area was off limits due to construction of the Marina Coastal Expressway, which ostensibly destroyed the mangroves. The different kinds of mangrove trees seen included common ones like Api-api putih (Avicennia alba) and Perepat (Sonneratia alba). This artificial shore also had seagrasses growing near the mangroves.
I've even seen mangrove trees settling on artificial seawalls on our northern coast. Like these little mangrove trees at Kranji near the Kranji Dam.
MORE photos of mangroves growing naturally on seawalls in Singapore in this wildsingapore flickr set.
Where do these mangroves come from? Where are the natural mangroves that produce the seedlings which settled on these artificial shores? What can we do to encourage similar natural regeneration on other stretches of artificial seawalls? These are indeed very interesting questions that hopefully can be explored in the future by people far more competent than I.
Why should we care about mangroves growing on our seawalls?
Mangroves and other natural ecosystems such as seagrasses and coral reefs can help maintain good water quality. They can be living 'barriers' that may help mitigate impacts of rising seas and climate change: such as flooding, saltwater intrusion into freshwater supplies, and impacts of more severe weather. Natural and wild ecosystems that are self-generating and self-sustaining are relatively inexpensive to maintain and provide a wider spectrum of experiences compared to manicured gardens. They can be beautiful and provide recreational enjoyment. Easy access will allow schools bountiful opportunities for nature-related learning. I am sure there are many more advantages that I have not thought of!
These details are part of City in a Reef: my feedback on the Draft Master Plan 2013.
Related links
Surveys to check up on the mangroves that settled naturally on Pulau Hantu's seawalls
- Mangroves on an artificial seawall at Pulau Hantu, Jan 2011
- Five islands in one trip! Jan 2011
- Sexy mangroves on the Hantu wall, May 2009
- Mangroves at Pulau Hantu, Apr 2009
Mangroves at the Marina Barrage
Other posts about mangroves in Singapore
More related posts