Monday, August 4, 2008

Seagrass Monitoring at Semakau (3 Aug 2008)

At 430am in the morning, a group of Team Seagrassers met up at Marina South Pier to make a trip down to the Semakau monitoring site. We scratched ourselves down to the seagrass meadow through the forested area, unceremoniously accompanied by the constant buzz of the mosquitoes.

I teamed up with Hannah to do Site 2. Site 2 is a bit of a challenge as the seagrasses are almost knee-deep (bearing in mind we are talking about vertically challenged ol’ me) in water in some parts.

Some of the quadrats also have 4 types of seagrasses – the Enhalus Acoroides (EA), Cymodocea Serrulata (CS), Halodule Uninervis (HU) and the Thalassia Hemrichii (TH).

The TH species here are quite errant. Why? No. 1 – forget about their sickle-shaped characteristics. No. 2 - it’s so much fatter than the other TH that I come across on other sites. Another way Shufen taught me how to recognise CS through the long thin stem, whereas the TH leaves comes from a sheath.

After more than an hour of (meticulous) monitoring, it was time to do some hunting. For some reason, the sargassum seaweed is in full bloom and covered many parts of the shore.

I saw this species of nudibranch for the first time.

We were fortunate that after the monitoring, the driver uncle agreed to give a Semakau tour, with Ria doing the commentary. Pulau Semakau is Singapore’s only remaining landfill situated offshore among the southern islands of Singapore. The current island was formed by the amalgamation of the then much smaller Pulau Semakau and Pulau Sakeng. It covers a total area of 3.5 square kilometres and has a capacity of 63 million m³. To create the required landfill space, a 7 km perimeter rock bund was built to enclose a part of the sea off between Pulau Semakau and Pulau Sakeng.

It is currently estimated that the landfill, which began operations on 1 Apr 1999, will last till 2040, as not all the cells are filled yet. The Ministry of the Environment and Water Resources, along with the National Environment Agency which manages the landfill, hopes this deadline will be extended through various waste minimisation and resource conservation initiatives.

Semakau Landfill is filled mainly with ash produced by Singapore's four incineration plants, which incinerate the country's waste, shipped there in a covered barge (to prevent the ash from get blown into the air) every night. Contrary to popular belief that Semakau Landfill would be another dirty and smelly landfill, the care put into the design and operational work at the landfill have ensured that the site is clean, free of smell and scenic. In fact, we ran into the Raffles Museum of Biodiversity Research guides who had a barbeque there the night before.

During construction, silt screens were installed to ensure that the corals were not affected during the reclamation works. The landfill is lined with an impermeable membrane, and clay and any leachate produced is processed at a leachate treatment plant. Regular water testing is carried out to ensure the integrity of the impermeable liners. (adapted from here.)

And oh, this structure is a reminder of the good intentions of men thwarted by opportunistic behaviour of others. Before it was abandoned, it was used by Shell to guide their vessels and powered by solar battery...which keeps on getting stolen.

As we left to go back to the pier on the bus, there were some excited shouts of black tip sharks sighting. Which just turned out to be stationary black rocks.

Before I headed back, I had lunch at Labrador Park food centre which was slated to be torn down next month.

I’m not sure if the food centre had any fans who had clamoured for it to remain, but I am so glad to be with fellow friends who are fans of nature, and who will clamour for its conservation when the time comes for it.

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