to 'build a reef' at Hantu: some issues
updated 3 Jun 06
"Singapore Underwater Federation ... aims to build
a coral reef in the lagoon enclosed by Pulau Hantu" media
Their publicised plans include the following, which raises some questions...
Census of Hantu and our reefs
SUF will "conduct the largest census of marine biodiversity undertaken
ST 31 Mar 06
How will the SUF census be different from the surveys of all our reefs
that are already ongoing and for which data is already available online?
How will this reef be 'built'?
"They are also planning to move corals from other reefs to the
CNA 30 Mar 06
Past coral relocation efforts in Singapore: have they worked? more
Where are these 'other' reefs from which corals will be taken?
"Plans are under way to create a simple sand filtration system
to eliminate most of the sediment from the water flowing into the
lagoon, creating a clear water habitat." ST 31 Mar 06
Does this mean the 'built reef' will be isolated from the surroundings?
(in effect, a giant aquarium). Filter-speak:
What does filtration involve? What are the risks to the habitat?
Where will this reef be located on Pulau Hantu?
Location of 'built reef' is as indicated below...
Pulau Hantu is made up of two smaller islands: Hantu Besar and Hantu
The map provided in the media
(above) suggests there these two islands are well separated and that
there are corals around each of the smaller islands.
In reality, there is a shallow lagoon between the two islands. At
low tide, this lagoon is exposed out of water. At high tide, the water
reaches about 1.5-2m in height on average. This allows comfortable
and safe swimming. While snorkelling is possible, diving is not practical
in the lagoon as it currently is.
Coral reefs have regenerated outside the man-made seawalls. There
are several submerged reefs near Pulau Hantu. These are called 'terumbus'.This
lagoon and the reef flats are already teeming with marine life.
What is the state of marine life on Pulau Hantu today?
Webpages with photos of what you can see
at Pulau Hantu right now.
To 'build' the reef in this lagoon will probably involve extensive
changes to the depth of the lagoon. What will impact be on existing
marine life there and in the surrounding reef flats and terumbus?
"The divers, however, face a difficult task because of poor visibility
caused by silt suspended in the water. It can be so bad that 'you
have to bump into coral to notice them', said Project Noah manager
Spencer Lewis." ST 31 Mar 06
Will SUF divers involved in the census be properly trained so as not
to damage our reefs as they do their census? See also Cashing
in on Corals about studies on the damage caused to reefs by divers
who touch corals.
(The visibility in our waters is not always that bad. In fact, the
vis at Hantu can be quite good and may be among the best of our Southern
islands, see chart below and discussion
of viz on the habitatnews blog thanks to Siva for the alert.
Professionals, scientists and regular divers in our waters generally
know how to manage underwater activities without damaging our reefs.
They would certainly not 'bump' into corals to find them).
Chew emphasised that 'the lagoon isn't just for divers', saying: 'It's
for anyone who wants to get wet and enjoy our marine life.'"
ST 31 Mar 06
How will the created reef be managed? In particular, will the impact
on the reef and surrounding habitats be well managed?
"Mr Lewis sees the likelihood of Project Noah developing into
a lucrative business" BT 31 Mar 06
What will the environmental impact be if the 'built reef' is run as
a commercial enterprise? Cashing in on corals:
impact of divers and boaters on reefs some extracts of studies
done on the issue.
Who are the project leads? What are their interests in the project?
More about why this is vague in the reports of
the SUF briefing. In the press release
(PDF file), Sydney Chew was identified as Managing Director of Aquos
Pte Ltd and SUF member. Here is the ACRA
printout (PDF file) about the company.
What are the issues in evaluating a proposal
to reef rehabilitation?
See this PDF document on the Reef Check website "Beware
Hype on Artificial Reef Rehabilitiation" a document of the
Coral Reef Initiative which in summary states, among others, that
"The most effective mechanism of rehabilitating coral reefs
is through mitigation of chronic human disturbances (e.g. sedimentation,
pollution and over-fishing), thereby facilitating natural recovery
mechanisms and building resilience, to any further disturbances, that
will be effective over large areas";
"In addition to effectiveness considerations, construction of
any engineered structure on a coral reef must be evaluated against
any potential environmental damage caused during construction or later
"Some innovative and new approaches to coral reef conservation
and management may have limited applications, there have been insufficient
peer-reviewed, long-term scientific studies of reef rehabilitation
using these techniques and few cost-benefit analyses to assess effectiveness
of the methods over natural recovery processes."
"Governments, international agencies, NGOs and other parties
[are advised] that they should carefully examine claims from commercial
and non-commercial groups selling or proposing ‘engineering’ solutions
for coral reef rehabilitation and to seek advice recognised scientific
bodies before investing in risky, unproven and expensive engineering
techniques which may exacerbate environmental damage and divert funds
away from more effective measures"