22 October 2010

Dredging near Cyrene, at Pasir Panjang Terminal until Nov 10

Dredging at the terminal near Cyrene Reefs started in Sep and will go on until Nov 10.
Here's an extract from the navigation chart showing the location of Cyrene Reefs and Labrador and Sentosa in relation to the dredging site.
Dredging stirs up sediments and makes the water murky. Why does this matter?

Cyrene has amazing seagrass meadows and coral reefs. Seagrasses, like other plants, need sunlight. Murky water is like haze. It reduces the level of light that reaches the seagrasses through the water, and mucks up the leave blades.

Do corals need sunlight? Yes, they do! Reef-building hard corals need sunlight because they harbour microscopic, single-celled algae (called zooxanthellae) inside their bodies. The algae undergo photosynthesis to produce food from sunlight. The food produced is shared with the coral polyp, which in return provides the algae with shelter and minerals. It is believed this additional source of nutrients from the zooxanthellae help hard corals produce their hard skeletons and thus expand the size of the colony faster. Thus clear waters that let sunlight through for photosynthesis is important for healthy reef growth.

Healthy corals are better able to cope with other threats, such as the recent spell of coral bleaching.

More about the impact of dredging and sand mining, about hard corals on the wild fact sheets, and what is sedimentation and why does it matter?

More about Cyrene Reef.

Dredging Works off Pasir Panjang Terminal
from Port Marine Notice No. 109 of 2010 dated 3 Sep 2010
This is a revision of Port Marine Notice No. 74 of 2010. The working areas and the working period have been revised. With effect from 03 Sep 10 to 30 Nov 10. 24 hours daily including Sundays and Public Holidays. Pasir Panjang Terminal and its vicinity (see chartlet above):

Dredging works will be carried out by the grab dredgers, “YTC V”/“YTC 15”, held in position by 2 spuds as anchors. The dredgers, with hopper barges in attendance, will have a circular safety working zone of 50-metre radius centred at the dredgers. Dredged materials will be transported to the designated dumping ground by the hopper barges assisted by pusher tugs. A crane barge, hopper barge and two tugs will be working at one sector at any one time. During the operation, the crane barge and hopper barge will be attended by tug boats. The tug boats will be used to shift the crane barge and hopper barge, when required to clear the fairway for vessels to berth or unberth. Safety boats will be deployed in the vicinity to warn the other craft to keep clear of the working area. Contact with the safety boats can be made via VHF Channel 08. Further general enquiries relating to the project can be directed to Mr Wong Wai Kin, the project manager at Tel 9643 5015 (email: wk.wong@yengtong.com).

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