18 October 2008

Bryopsis bloom on Sentosa

Hairy green seaweeds (Bryopsis sp.) carpeted the Sentosa shores when we visited yesterday for TeamSeagrass monitoring.
What are Hairy green seaweeds and is a bloom a bad thing?

Bryopsis seaweeds comprise a clump of fine filaments (6-8cm long) attached to a hard surface, such as small stones and coral rubble.

In some, the filaments form long feather-like structures that taper at the tips.
In others, the filaments are long, single strands with only a little bit of branching. They come in various shades of green, from bluish green to olive green.According to AlgaeBase there are more than 60 current Bryopsis species. So it's probably beyond mere mortals to figure out what kind of Bryopsis are carpeting Sentosa.

During a bloom is when we look out for tiny creatures that live among the seaweeds.Sometimes, there are countless tiny amphipods among this fine seaweed. These animals are not shrimps. They belong to a different group, the Order Amphipoda. They are sometimes also called beachfleas, sand hoppers or sandfleas. They are often the most numerous and most diverse of bottom-dwelling crustaceans.Another creature that occurs in large numbers among Bryopsis are these unidentified slugs. They are probably sap-sucking slugs (Order Sacoglossa) that suck the nutrients out of the seaweeds. They are really hard to spot as they look very much like the seaweeds!Here's a closer look at the slug.

There are probably lots of other animals that feed on the seaweeds especially at high tide. And the tiny animals found the seaweeds are part of the food chain for bigger creatures. So a seaweed bloom is not necessarily a bad thing.

Bryopsis blooms are quite encountered regularly on our shores. At times, the seaweeds are plentiful, like yesterday. And at other times, they are very sparse. Blooms don't last very long, seldom more than a month.

This might be part of a natural cycle. Seaweed blooms can be triggered by fresh nutrient inflows. Could the rainy weather recently have washed more nutrients from the forested natural cliffs that border the shore?

Or could the blooms be the result of increased sedimentation from coastal works nearby? These works include
That is why regular monitoring work such as that done by TeamSeagrass is important in gaining a better long-term understanding of our shores.

17 October 2008

Cyrene Quickly

Seems nothing can keep us from Cyrene Reef! Another visit, albeit a short one, with lots of work done and interesting sightings as usual.
Our first evening trip to Cyrene was held up by rain and boat problems. As usual, the team found ways to amuse themselves with marine finds even at the jetty.

We were also joined by a film crew from threesixzero who were there to feature Sijie and Chee Kong of the Star Trackers.Here is Sijie explaining the programme.
While the paparazzi were taking photos of the event.

After some patient waiting and lots of hope, we were finally heading out to this amazing reef in the midst of our port and petrochemical plants.
By that time, we only had about 45minutes left of daylight and we had to work fast.In no time at all, the Star Trackers and friends had already marked out in yellow flags, the locations of many Knobbly sea stars (Protoreaster nodosus).

While Knobblies are found on many of our other reefs, Cyrene Reef is so far the only reef in Singapore where we've seen many juvenile Knobblies.These sea stars come in all kinds of colours and patterns. Chay Hoon even re-discovered the 'blonde' Knobbly. We're not sure if it's a different species or just a different form of our Knobbly. Chay Hoon and Marcus found all kinds of interesting stuff, and Andy filmed a strange beautiful anemone.

My special find was this Giant clam (Tridacnea squamosa), which is no longer very common on our shores.So it's most surprising to find one just opposite our world class container terminals!See the Giant clam on the lower edge and the port facilities on the horizon.
I was excited to see the snail shell because the Spider conch (Lambis lambis) is such an endearing animal. But the snail has died and its shell taken over by this special hermit crab that so far, I've only seen at reefs.I'm not sure what kind of hermit crab it is, possibly a Dardanus sp. It has such cute eyes on thick stalks.The colourful Mosaic crab (Lophozozymus pictor) is also another treat. And I saw two of them today, my first encounter on Cyrene Reef. I do notice that these crabs, which are on our Red List, are usually seen in some numbers and then not again for some time. These crabs are among the most poisonous on our shores and should not be eaten. Even cooking does not destroy their toxins.As dusk fell, the night shift started. And octopuses came out to play. A Master of Disguise, the octopus can change its colour and texture instantly. This octopus was smooth and sandy coloured as it moved across the sand.And instantly became more textured and mottled as it settled near a soft coral.

My job today was to take good sharp photos of the tiny features of the marvellous range of seagrasses found on Cyrene Reefs.There's the amazing Noodle seagrass (Syringodium isoestifolium) which is cylindrical and has a pointed tip. The seagrass has air channels inside it to help it float.And of course Needle seagrass (Halodule sp.) which is thin and flat. Halodule uninervis has a pair of tiny 'ears' at the tip. It also has a more prominent mid-vein.Then there is Cymodocea serrulata which has fine serrations on the tip (left photo). While our longest seagrass Tape seagrass (Enhalus acoroides) has a smooth tip (right photo).

Tape seagrass is also differentiated by the inrolled edges along the length of the leaf.And while taking a photo of the seagrass, I saw this tiny little slug!It appears to have two pairs of 'tentacles', one pair in front and another pair on top of the head. It's transparent (so much so that its guts can be seen) and has fine white lines that mimic the veins of the seagrass!
Here's another look at the slug. I have no idea what it is.

This beautiful reef is surrounded by massive reclamation as well as major dredging between Pulau Bukom and Jurong Island and on the mainland.The big dredger could be seen just off Cyrene Reef during our trip.
In addition, the Reefs are also the target of fishermen who leave large fish traps behind.
Alas, all too soon it was time to leave Cyrene. The petrochemical plants at Jurong Island start to twinkle in the falling light and rising tide.
There will not be many more suitable tides to visit the rest of this year. We hope Cyrene Reefs will keep well in the meanwhile.

Sammy the whale shark: some updates

A leading Dubai conservation group has put pressure on releasing the whale shark. According to recent media reports the Emirates Marine Environmental Group (EMEG) yesterday issued a statement “to pressure Atlantis into tagging and releasing this shark back into its natural habitat as soon as possible”.
EMEG was set up in 1996 under the patronage of Sheikha Manal bint Mohammed bin Rashid Al Maktoum, the wife of Sheikh Mansour Bin Zayed, minister for presidential affairs.

Until yesterday, EMEG, which works on some conservation projects with the developer Nakheel, had remained silent on the matter, although individual members had expressed their concerns privately. Yesterday’s statement, however, was unequivocal.

According to The National, the controversy over the whale shark has now reached the highest executive levels of Kerzner International and Nakheel, the joint-venture partners behind the Atlantis resort. A high-ranking official at the Ministry of Environment and Water is also believed to be looking into the matter.


Already cashing in on the whale shark
The National reports
There is little doubt that the creature has become a major attraction at the aquarium, which has been selling toy whale sharks in its shop for Dh99 (US$27) each.

Labels on the toys state that “Atlantis proudly supports the Kerzner Marine Foundation”, which on its website describes itself as “a private, non-profit foundation that fosters the preservation and enhancement of global marine ecosystems through scientific research, education, and community outreach”.

However, the foundation is not an entirely independent organisation; it was set up in 2004 by Kerzner International, the hotel group behind the Atlantis, and Mr Leibman is one of five directors on its board.

The foundation, which is based in Florida, failed to respond to repeated requests for a statement. Management at the Atlantis in Dubai and at the hotel chain’s global communications office in New York were also unavailable for comment.


Was Sammy purposely hunted for the aquarium?
Gulf News also reported that
Sammy was not rescued by the Atlantis hotel, Gulf News has learnt, after speaking to ex-Atlantis employees who say that plans to have a whale shark in the hotel's Ambassador aquarium were clear from the beginning.

According to several previous employees who spoke to Gulf News on condition of anonymity, there was never been any plan to release Sammy and the hunt to find a resident whale shark was relentless, with fishing boats heading out every night to find one.

An ex-employee from the Marine and Water Park department at Atlantis, who left the company this summer, said the hotel's plan to acquire a whale shark was known by all since the beginning.

"It was going to be part of the attraction. There was no mention of a release. We were always told it was coming," they said.

"When I joined the company the dolphins were already there but they were going fishing everyday to collect sharks and fish. They didn't catch many sharks though. A few bull sharks died from shock of being in a different environment," they said.

"They were looking everywhere for a whale shark. It has just become so annoying to read about this knowing they lied. It wasn't rescued."


Gulf news also reported the views of the fisherman who caught Sammy.
The fisherman who caught Sammy the Whale Shark said he would do it again if he came across another fish in the same distress. All that mattered to him was the well-being of the giant fish.

Whether Sammy stays in the Atlantis tank is not his immediate concern but the artificial environment could offer the world's biggest fish a good home, said Hamed Al Rahoomy, an Emirati fishermen and previously chairman of the Fishermen's Association.

Annually, one or two whale sharks are caught accidentally or found by fishermen dead from boat collisions, said Rahoomy, adding that having one in a tank is a good means of educating the public and fishermen on the gentle fish.

"I am working for Atlantis to collect all the fish for the aquarium," he said.


The facebook group on the issue now has more than 7,000 members.

16 October 2008

Tropical whales, in Singapore?

Sadly, a whale that got stranded in Pahang last week has died.An autopsy showed the female whale had swallowed a black plastic bag, a rope and a bottle cap, which clogged its intestine.

It's frustrating that just a few carelessly thrown items like these can kill such a magnificent creature. This is certainly something to highlight in the on-going efforts to educate about marine litter.

The whale was identified as Bryde's whale (pronounced "Bro-dess") aka the tropical whale (Balaenoptera edeni). Another Bryde's whale stranded and died in Sabah (East Malaysia) in 2006 (links to news on this on the Raffles Museum News blog).

What are tropical whales and were any encountered in Singapore?

Whales are like us
From the little that known about the tropical whale, they are much like us. The tropical whale can live up to 72 years and usually lives alone or in pairs, although several may gather at feeding sites.
They eat fish and krill and grow to 11.5-14.5m and weigh 12-20 tonnes. (from the BBC website)

Singapore whales?

Those of us old enough to remember the old Singapore National Museum when it still had its natural history component will surely recall the whale bones that hung at the entrance. This whale actually died in Malacca and its bones sent to Singapore.

This skeleton was of a 42 ft baleen whale from Sabatu, near Malacca, acquired on 19 June 1892. In the 1970s, when it was decided that the Museum should "concentrate on arts and anthropology" and give up its zoological collection, the skeleton was among the exhibits given up. This skeleton is now at the National Museum in Kuala Lumpur, Malaysia. (from the Raffles Museum of Biodiversity Research website).

Here's more details about the history of this whale skeleton from a news article carried on the Raffles Museum News blog.

"There is one certain record of the Blue whale from Malaysian waters. An immature 42ft was standed on beach at Kg Sa'Batu Malacca on June 19, 1892".
According to Hanitsh (1908: 13), a "pagar" was built around it to prevent it getting back to water at high tide and was left to die. "It lingered for a week making a bull-like noise for 3 days, no use was made of the blubber but DRR Harvey, then Resident Councillor of Malacca, had the skeleton cleaned and sent to the Raffles Museum.
"Nothing could be done with it at that time owing to lack of space in the existing galleries. In 1907, it was hung over the passage-way between the old and new building. At first it was identified as Humpback Whale.

"Actually though it might possibly occur here, there is no record of the Humpback from the Malaysian sub-region. "Later this Malacca specimen was re-examined and the designation changed to the Indian Fin Whale, a synonym of Blue Whale."
Here's another photo of the whale bones while they were in Singapore, on Okinawa Soba's flickr site.

Although the whale bones have left our shores, they remain part of our memories. The National Museum (which is now completely devoid of any natural history) in its 120th anniversary celebration of 120 voices had this among the many quotes of museum memories:

"I graduated from the University of Malaya and joined the museum in 1956 as the first local curator of zoology. The museum then was the biggest building along Stamford Road; there was nothing else like it. It was only shophouses all the way to the seafront. It was a stately awesome building, the visitors would walk through the main entrance, stand in the Rotunda and look up at the skylight. That was something worth looking at. You walked up the stairway and suspended above you was a huge skeleton. You thought it was a dinosaur but it was actually a whale. Not many people have seen such a sight before, it was a fantastic introduction to the museum." – Eric Alfreds, Curator/Director, Raffles/National Museum, 1950s - 70s
Members of the public still reminisce about the whale bones during the outreach efforts by the ToddyCats, volunteers of the Raffles Museum of Biodiversity Research.

Update 13 Jul 2015: From Google News of the New Straits Times 27 Jan 1994 about the False killer whale that was stuck in Singapore, Tuas Bay.

From the DNA of Singapore on the Lee Kong Chian Natural History Museum website:

"In 1994, a 3.75 m female False Killer Whale (Pseudorca crassidens), swam into Tuas Bay and stayed for a week. It was believed to have been trapped in the bay and unable to find its way out despite attempts being made to guide it out. It was later found dead off Tuas."

Creeping with the tides: how do marine snails keep up?

To stay alive, small intertidal creatures need get with the tides. At low tide, a vast area is exposed for these animals to feed, find mates and do other stuff without worrying too much about underwater predators. But at high tide, they need to get to a safe place in good time.
Periwinkle snails (Family Littorinidae)
For a marine snail, this usually means getting above the waterline at high tide to avoid hungry fishes. Since snails are not the speediest of creatures, they need to get started in good time and get high enough. And tides don't rise to the same height every day, nor do they occur at the same time. And snails don't carry a watch or handphone.

So how do they do it?

Tiny Tide Travelers May Sense Gravity
Erin Espelie, LiveScience.com Yahoo News 15 Oct 08;
Life is no beach for tidal creatures that must migrate in sync with the waterline.

Imagine trying to gauge the tides that sweep through a Kenyan mangrove forest: how far the water rises up a given tree depends on the season, the phase of the moon, and the tree's position. Yet a pinkie-toe-size snail, Cerithidea decollata, seems to predict the height of the incoming tide. It ascends a trunk just high enough to escape inundation, then descends when it's safe to forage in the mud below.

To find out how, Marco Vannini of the University of Florence and colleagues observed the snails on plastic pipes - imitation mangrove trunks - that they stuck into the mud.

The scientists tried obscuring any chemical markers left behind by the tide line or the snails themselves, and still, the snails climbed to the right height. Nor do the predictive gastropods seem to be using visual cues from overhead foliage. They aren't even counting the "steps" they must creep to beat the tide: when the scientists tilted the pipes, the snails readily climbed the extra length.

When lead weights were glued to the snails' shells, however, they adjusted their ascents; the heavier the weight, the shorter the climb. So it seems that the snails' are sensitive to their own energy output. Perhaps, Vannini suggests, they actually perceive the variations in gravity that drive the tides: before a low tide, the snails feel heavier and therefore don't climb very high.

The research was detailed in the journal Animal Behaviour.

15 October 2008

Raffles Lighthouse: Singapore's Southernmost point

Raffles Lighthouse is what Singapore's reefs might be if we don't mess with them.
A4 Poster: Raffles Lighthouse
It is located on the tiny island of Pulau Satumu, which is ringed by stupendously rich reefs.

There was a flurry of articles today about the very lucky (to us) people who work at the lighthouse on Pulau Satumu.

As part of Singapore Maritime Week, an exhibition “From Lighthouses to Electronic Charts: An Exhibition” will be held at VivoCity, Central Court A, from Friday to Sunday, 10am to 9.30pm. The exhibits include models of lighthouses and a life-size buoy used to mark sunken wrecks.

Here's some titbits about Raffles Lighthouse from the media articles

Singapore shipping industry: addressing environmental concerns

What do shipping and related industry leaders have to say about the environmental impact of shipping?

Business Times interviewed a panel including leaders of the Singapore Shipping Association, PSA Singapore Terminals, Shell, NTU Institute of Environmental Science and Intertanko Asia-Pacific.

There appears to be acceptance of impact of emissions of sulphur, nitrogen and carbon. As well as to references that "shipping is still the most efficient means of transport", with Shell saying that "on a per ton, per mile basis, shipping is usually the most environmentally friendly mode of transport". One lament is that shipping is "an easy target to blame".

The focus is on solutions that are "pragmatic". Shell mentions the need for efficiency: "only around 30 per cent of marine fuel is used to power the vessel, the rest is dissipated as heat", and others also pointed to ways to improve efficiency through design and operation of ships.

There is much reference to legislation and mention of the International Maritime Organisation (IMO)'s recent rulings on sulphur emissions.

There is also mention that the "industry also needs to improve our image more" and to "educate the public".

One suggestion: "We need to let people know how important shipping is to world trade. Shipowners have a purpose to serve world trade which could not have grown without shipping. We also need to engage people from outside the industry to help them understand what we are doing. For example, we can arrange visits to ships to see how modern they really are."

Why should we care about shipping?

In a separate article, NOL remarked that "shipping is not as obvious a factor in people's lives as aeroplanes or cars which they regularly experience at a personal level. Often the only time shipping comes into the public eye is when something bad happens".

"Prescriptive regulations are not the answer as they only tend to lead to loopholes". The shipping must want to improve and the drive to do so could come from customers who call for compliance with sustainable practices.

"Enlightenment is nice as long as you are not being driven out of business by competitors because they are not doing the same as you."

14 October 2008

Filling the fish gap: Gentler trawling and new aquaculture approaches

If we don’t do something about the over fishing, stocks of wild fish will be dealt a death blow. Some fascinating new ideas are explored, in a recent article about a huge gap between global demand and sustainable supply of fish.

“On a global basis today, we have an average annual consumption of 15-16 kilos of fish per person" And as the population grows, to meet the demand, "we need to double the production of farmed fish within the next 20 years"

And what are some the things that need to be done? Among some new ideas being explored, using bubbles to fish and a simple realignment of the trawl net by 90degrees to avoid wasteful bycatch.

Take only what we need, and use what we take
We need to develop technology for more selective and gentle capture of species in the sea to enable natural growth in the stocks and only capture the quality we actually want.

Increase the efficiency of the aquaculture sector. Among others, we must stop using fish as feed for farmed fish. Fish caught at sea must be human food. Feed alternatives considered include plant oils and proteins, or convert natural gas to bio proteins.

We need to succeed in finding some new species of farmed fish and develop technology that enables a smarter and more cost-effective production of the fish species we are already farming.

One idea being developed is a bubble trawler which uses air bubbles instead of a net to surface its prey: the 3 mm long, protein-rich Calanus finmarchicus. This tiny creature contains large amounts of proteins as well as marine fats. “Capturing just one percent of this biomass would cover the requirements for the Norwegian aquaculture industry.”

Another idea is to improve trawling, “which accounts for 40 percent of the world’s total fisheries production”. As such, improvements in trawling will have widespread benefits.

One simple, but extremely effective solution to make trawling gentler and make it possible to catch fish of the correct size without damaging the small fish, is to turn the trawl net 90 degrees. This resulted in less turbulence and the meshes remain open when the trawl is stretched so that the small fish escape and the fish that are large enough are damaged to a much lesser extent. Energy consumption was also reduced.

Batteries: rechargeable or disposable better?

I often feel like a walking battery shop when out exploring the shores. With batteries in the two cameras and two flashes and torch and spare torch. And of course, back-up batteries. And since I use rechargeables, and the trips are back-to-back, there's usually another set of rechargeables charging at home while I'm out.

My rechargeable batteries last for about a year, but I do go through quite a lot of them at the same time.

So which is better for the environment, using rechargeable batteries or one-time disposable ones? Here's a recent article discussing the issues:

Plus and Minus: Disposable vs. Rechargeable Batteries
Steve Uydess, LiveScience.com Yahoo News 12 Oct 08;
The dawn of the internet and the Information Age generated tremendous new demand for power, as companies built their own networks and shifted to computer-based operations. Additionally, as technology shrinks to more portable proportions, more and more of that power will come from batteries.

New batteries certainly look shiny and clean and easy to dispose; however, as anyone who has left a battery sitting around for too long can attest, most batteries contain toxic chemicals and heavy metals that are harmful to people and the environment.

Given the fact that Americans alone purchase nearly 3 billion dry-cell batteries per year (for laptops, toys, phones and tools) and another 100 million wet-cell batteries (for cars, motorcycles and boats), even trace amounts of heavy metals quickly add up to a serious environmental problem.

As American dependency on battery power increases with each new gadget that hits the market, the question of how to power these devices has risen to the fore. Dry-cell batteries today come in either rechargeable or disposable varieties, so it is worth examining the benefits of each before deciding which to buy. We'll see how they stack up in the following three areas:

Toxic materials

Used: All batteries need some sort of heavy metal to function properly, and until the mid-1990s, most disposable alkaline batteries (think AA or AAA) contained up to 7 percent mercury. Since a 1996 law regulating mercury levels was passed, most companies have eliminated (or nearly so) its presence. Duracell, for example, uses steel, zinc and manganese.

On the other hand: In a classic catch-22 dilemma, the lack of expensive heavy metals means there is less incentive for companies to recycle them. Unlike single use, rechargeable batteries continue to make use of potentially toxic heavy metals such as cadmium, nickel and lead. While these metals still possess the same hazards, the long life of these batteries and abundance of recycling centers means these metals can easily be diverted from the waste stream.

Bottom line: Disposable batteries, while less toxic than they used to be, still end up in landfills more often than not. Rechargeable batteries are a boon for the environment if they are actually being recycled and not dumped into landfills or incinerated.

Lifetime vs. cost

Lifecycle: In these terms, rechargeable batteries are the clear winners, especially in devices that are used for extended periods, like computers or digital cameras. A typical battery of this type may be recharged 500-800 times before it loses its ability to hold a charge, at which point it can be recycled. Even factoring in the higher price of rechargeable batteries, you still would need hundreds of disposables to equal that kind of lifespan.

On the other hand: It should be noted that disposable batteries hold their charge better in devices that are only used intermittently, such as flashlights, toys or remote controls.

Bottom line: Even if environmental issues are secondary to economical issues in your book, rechargeable batteries will save you lots of green in the end.

What next

Recycle-ability: Rechargeable batteries again have the clear edge, but it is important to remember that rechargeable batteries are not the only type that can be recycled.

Some facilities have begun to collect and recycle disposable batteries. Also, many button-cell batteries (found in hearing aids and watches, for instance) are in high demand due to their valuable heavy metal content and ease of handling.

On the other hand: Still, neither of these types of battery can be recycled as easily as rechargeable batteries, due in part to the Rechargeable Battery Recycling Corporation's (RBRC) Call2Recycle program. As part of the rechargeable battery industry's recycling initiative, there are over 50,000 recycling centers nationwide, many at large retail chains like Home Depot, Circuit City and Sears. This greatly reduces the likelihood of consumers simply tossing their batteries in the trash. After all, a recycling program is only useful if people can easily participate.

Bottom line: Consumers should take advantage of recycling programs to ensure that their batteries are properly discarded. Also, since roughly 80 percent of batteries sold are disposable alkaline, it is up to consumers to transition to rechargeable batteries when possible.


So it seems the key to being green is to recycle those rechargeable batteries.

Do we have battery recycling in Singapore?
I consulted Eugene Tay of AsiaIsGreen on this.

Eugene shared NEA's explanation why there is no need to recycle batteries in Singapore.
Our main concern with the disposal of household batteries is the mercury content in some types of batteries as they pose a pollution problem during disposal. To make sure the mercury does not become a pollution problem, the National Environment Agency (NEA) has, since 1992, imposed a limit on the mercury content of batteries sold in Singapore. This limit is 0.001 per cent (by weight of mercury) for mercury-oxide batteries and zinc-carbon batteries; and 0.025 per cent for alkaline batteries.

With this control in place, we can allow household batteries to be disposed of with other household waste at our waste-to-energy plants. These plants have air pollution control equipment to ensure emissions are clean and meet stipulated standards.


He also said that batteries used to be collected by Citiraya for recycling. But the company has since been busted for fraud.

Eugene also shared that for handphone batteries, Motorola collects them, with collection locations on the NEA website.

See also Batteries in Singapore safe for disposal Teh Jen Lee, The New Paper 5 Mar 09

13 October 2008

How much is seagrass worth?

An acre of seagrass is worth about $4,600 per year, a recent study found. The total benefits of the 156-mile-long Indian River Lagoon estuary is estimated at $3.7 billion.

Living within about a third of a mile from the lagoon adds $20.3 billion to real estate values and $47 billion to the five-counties along the lagoon.

In other news, China announced a 26 million yuan (3.8 million U.S. dollars) protection project for dugongs, to save them from extinction in south China's Guangxi Zhuang Autonomous Region.

The project, to be completed in 2009, includes the building of a scientific research center, a sea animal rescue center, watchtowers and the purchase of equipment, such as patrol boats, in the Hepu Dugong National Nature Reserve, the only sanctuary of its kind in the country for the animal.

Singapore has seagrasses too. And possibly dugongs as well.
You can make a difference for them by joining TeamSeagrass to monitor our seagrasses and gather data to protect the habitat and dugongs and other animals that depend on it.

Works on Sentosa bridge continues to Apr 09

This new road into Sentosa is in anticipation of the over 15 million of visitors to Sentosa when the Integrated Resort opens in early 2010. The S$80 million, 710-metre, 3-lane bridge will run parallel to the existing causeway which connects Sentosa to the mainland. It is expected to be completed in Sep 09.

Works on the bridge started in May 08. This construction is in addition to reclamation at Sentosa for the Integrated Resort, as well the massive Pasir Panjang extension project. The natural shores nearby include those on Sentosa and Labrador.

Construction of a new bridge from Pulau Brani to Sentosa
From Port Marine Notice No. 188 OF 2008 dated 13 Oct 08

This is a revision of Port Marine Notice No. 89 of 2008.

The working period has been extended. With effect from 01 Nov 08 to 31 Apr 09, at Selat Sengkir (see plan)New bridge construction works will entail steel pipe piling, drilling and socketing of piles and removal of rocks from pile locations. Crane and work barges will be used for the piling works and transportation of equipment. Barges will travel through the Selat Sengkir water to the working area. Barges are expected to travel
in/out of the Selat Sengkir water up to 4-6 times a week for material delivery and equipment transportation. A safety boat will be deployed to advise all craft to keep clear of the working area. Further enquires relating to the project can be directed to Mr Chris Kelly, the project manager, at Tel: 9118 2802, email: chris_kelly@macdow.com.au

Widening of existing causeway and causeway extension works at Sentosa
from Port Marine Notice No. 189 OF 2008 dated 13 Oct 08

This is a revision of Port Marine Notice No. 90 of 2008. The working period has been extended. With effect from 01 Nov 08 to 31 Apr 09, at Cruise Bay, off Sentosa (see plan):Widening works will entail steel pipe piling and removal of existing revetment. Crane barges and work barges will be used for the piling works and transportation of equipment. A safety boat will be deployed to advise all craft to keep clear of the working area. Further enquires relating to the project can be directed to Mr Chris Kelly, the project manager, at Tel: 9118 2802, email: chris_kelly@macdow.com.au

2009 tide tables are out!

I've just got 2009 tide tables today! And thus, planning for next year's shore explorations.
Here's some highlights of the 2009 tides, and more about low tides in Singapore.

Highlights of the 2009 tides
  • There's no low tide during Lunar New Year 2009! Rather odd. Since I first started visiting the shores in 2001, there has always been a low spring on LNY eve and the first two days of the New Year. And they were a good excuse to be anti-social and avoid pesky visiting.
  • There are extremely low evening tides until March. Unusual. In the past, these very low tides usually only happen in the morning.
  • We get to rest in March. There's virtually no spring tide the entire month.
  • The first predawn spring low trips start end April and lasts until August. So best to enjoy sleeping while we can. Once the morning lows start, it's back to jet-lag 4 hours of sleep a day.
What's the big deal about low tides
Isn't there a low tide every day?
Yes, it's true, there is a 'low' tide every day. But a 'low' tide can be anything from 1m to -0.1m, yes, that's MINUS zero. To understand why this is so, let's start with the basics.

What causes the tides?
A whole bunch of stuff can affect tide height. But three main things are behind the tides
  • Gravitational pull of the moon
  • Gravitational pull of the sun (although much further away, the sun is gianormous)
  • The rotation of the earth (the way your laundry in a spinning washing machine moves outwards)
When the moon and the sun are lined up, their effects are combined resulting in a higher high tide and a lower low tide. This is called a spring tide because the water appears to spring up more rapidly than usual. Thus spring tides happen around a new moon (moon is just a thin cresent) and a full moon.

At other times (i.e., quarter moon), the effects of the moon and sun are not combined so there is a smaller difference between the high and low tide. This is called a neap tide.

There's an animation of this on the NOAA website, and a very 'cheem' explanation on the wiki on tides.

What's so special about a low spring tide?
During a super low tide, we can get a quick glimpse of a part of the shore that is seldom exposed. Also, usually a larger area of the shore is exposed, since the low tide is a lot lower. So there is more to see in terms of variety and area uncovered. But remember the 'spring' part of this low tide: so the tide moves fast and the window of low tide is usually short, about an hour at most.

Guided walks on our shores are usually held during low spring tide. If you go during a not so low tide, there isn't as much to see. Although there is always something to see on our shores at any tide. For example, stuff clinging to rocks, coastal plants, birds and more. See the Adventures with the Naked Hermit Crabs blog for some sightings during their free Chek Jawa boardwalk tour which is conducted at any tide.
Natural cliffs of Sentosa
In this photo of the natural shore of Sentosa at low spring tide, you can see the mid-water mark as the dark portion on the natural cliffs. The area exposed at low spring tide is quite different from that at higher tides. It can also be dangerous to go at the wrong tide, or to be unaware of the turning tide as you might get trapped. Especially on a shore such as this one.

Not all shores can be visited at the same tide level. Some shores in Singapore require lower tides than other shores for a safe and enjoyable visit. It's thus important to go with experienced people and with shore guides. You will be safer, and also see and learn more about our shores.

In Singapore, low spring tide happens before sunrise around April to August (at about 2-3am, hence the sleep deprivation), and then after sunset in October to February. Often, there are no low spring tides in September and in March.

Low spring tides don't necessarily happen on weekends.

Low tides don't happen at the same time every day. This is because the moon takes more than 24 hours to go around the Earth. So the low (and high) tide shifts by about 50 minutes every day.

The tides can differ from predictions depending on the winds (which can raise water levels) and the barometric pressure (the pressure of the miles of atmosphere on the sea level). Also, we've found, when the spring tide changes from evening to morning and visa versa, the tidal prediction can be off.

The rough tide times for Singapore is available online on the NEA website. But these are generally not detailed enough for our purposes in planning trips to our shores. To buy the tide tables, go to the MPA website for the list of retailers.

Here's some tide tables available online for some sites (provided mainly by marinas).

Here's more about tides with photos of Chek Jawa at different tide heights on the wildfact sheets on the wildsingapore website.

Here's a great post about King Tides on the The Malaria, Bedbugs, Sea Lice, and Sunsets blog by Rick MacPherson.

12 October 2008

Revitalizing Florida's coral reefs: nurseries and finding tough strains

New approaches to help damaged reefs recover and survive climate change include setting up coral nurseries and finding resilient strains of hard corals.

Although corals grow so slowly that "it's like watching paint dry,", coral nurseries are considered cheap, as ecological experiments go, so it's very cost-effective and "very promising."

There will also be efforts to mitigate damage to reefs. Florida already has a reef-resilience program that closely monitors bleaching events. Also considered are restrictions for zones with largest corals and largest number of coral colonies, such as improving law-enforcement protection, and keeping lobster and crab traps away.

Singapore has also started a coral nursery at Pulau Semakau, although the area near the nursery is also used to park oil rigs being serviced, and for a fish farm.

Researchers work to revitalize Florida's coral reefs
Ludmilla Lelis, Orlando Sentinel 12 Oct 08;
Scientists trying to save Florida's diminishing coral reefs are using new approaches to help damaged reefs recover and survive a changing climate.

Damage from environmental problems, including climate change, is inevitable, they say, so they focus their work on what they can do. Through resiliency research, they hope to find the reasons some corals can overcome problems, and which are the more hearty corals that should be protected. Other scientists are preparing for the restoration of damaged reefs by growing the corals to replace them.

The two approaches could help in the battle to save corals that are being ravaged by pollution, ships, tropical storms and bleaching -- a phenomenon that leaves corals colorless and lifeless.

Nurseries for recovery

Two South Florida projects are growing future reefs in nurseries in Biscayne National Park. Coral nurseries are growing pieces of coral, which would be transplanted to damaged or dying reefs elsewhere.

Growing coral had been a hobby for the aquarium trade, but it has become a crucial scientific project, said James Herlan, a graduate student at the University of Miami's Rosenstiel School of Marine and Atmospheric Science. At the school's nursery in the national park, he glues fragments of staghorn coral onto cement platforms with a nontoxic epoxy.

"Coral nurseries in the Caribbean are a newer idea, but there is now more of an urgency to do this," Herlan said.

The underwater nursery has survived through trial and error. The corals are sprouting their distinctive hornlike shapes at a rate of 6 inches a year, just as fast as they would in the wild.

"It's cheap, as ecological experiments go, so it's very cost-effective," Herlan said. "It's very promising."

Biscayne National Park also runs a coral nursery, under a dock at Adams Key, using slow-growing boulder coral. Richard Curry, the park's ocean, reef and science manager, had rescued pieces from ship groundings and other accidents. He has made it a community project, using volunteers to epoxy the pieces to PVC pipes, laid in neat rows under the dock.

"It's like watching paint dry," Curry said of how slowly the corals grow. But he thinks it's good insurance for the future.

"We're not at the crisis yet where we need to have something like a 'captive breeding' program," he said. "But we will someday, and hopefully we'll be ready for that."

Finding resilient strains

Other scientists have focused on making reefs more resilient.

Pollution and the summer doldrums -- long stretches of tropical heat -- can spark a massive bleaching. Coral, responding to the stress, expels the colorful algae that normally live inside it, leaving the coral a white, lifeless skeleton. But some coral colonies can survive and grow back more quickly than others.

Researchers want to know why some reefs rebound, hoping to use that knowledge to better protect the hardier patches of reef.

Florida already has a reef-resilience program that closely monitors reef zones when bleaching happens.

No South Florida zones are immune to bleaching, according to a recent study. However, some zones with the largest corals and the largest number of coral colonies need to have more restrictions that protect them from damage. For example, a reef-resilience conference in Key Largo earlier this year came up with 129 strategies that could help the reefs better survive, such as improving law-enforcement protection of sensitive areas, and keeping lobster and crab traps away from living reefs. State officials already plan to end one environmental problem. Outfalls, pouring treated sewage into the ocean, will be shut down by 2018.

However, the greatest test of resiliency is whether coral reefs can withstand rising sea temperatures.

University of Miami Assistant Professor Andrew Baker has found that some corals appear to be more heat tolerant than others. The advantage apparently depends on microscopic algae living inside the corals. Some algae are more heat-tolerant. The corals that persisted after bleaching tend to have more of those heat-resistant algae.

With a $150,000 Pew Fellowship, Baker will spend the next three years trying to find ways to boost that natural heat tolerance, including injecting those algae inside the coral's limestone skeletons.

"We're faced with an unfortunate inevitability that global warming is here to stay even if we can bring down our emissions, so we need to do everything we can to save as many corals as we have left," he said.

Gradually, he will take his laboratory findings to larger reefs in South Florida and hopes to team up with coral nurseries to make sure that corals being grown will be better able to withstand global warming.

"This is not going to save the world's coral, but we may be able to find techniques that we can offer in a package of solutions for reef managers," Baker said.

"A failure to act guarantees the corals will be lost."

LinkWithin

Related Posts with Thumbnails