Similar dredging took place in the same area in Apr-Aug 09 and Aug-Dec 09, and seemingly related dredging and vibracore sampling took place in Jun 09. Although these were not referenced in this current Notice.
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.
More about hard corals on the wild fact sheets, and more about sedimentation in Singapore waters and other threats to our reefs on the Coral Reefs of Singapore website.
Dredging works at East Keppel Fairway
from Port Marine Notice No. 22 of 2010 dated 24 Feb 10
This is a revision to Port Marine Notice No. 150 of 2009. The working area and working period have been revised. With effect from 25 Feb 2010 to 24 Aug 2010. 24 hours daily including Sundays and Public Holidays. At East Keppel Fairway and its vicinity (see attached chartlet, above):
Dredging works will be carried out by a Trailing Suction Hopper Dredger (TSHD) in sectors A, B or C. While dredging, Queen of Penta Ocean will maintain a speed of about 2 knots. The TSHD will only dredge in one sector at a time. When moving from the dredging area to the dumping ground, she will proceed at a safe speed of not more than 12 knots depending on the traffic conditions and visibility. Contact with the TSHD can be made via VHF Channel 18 or 12. Further general enquiries relating to the project can be directed to Mr. Y. Mitsunari, the project manager at Tel: 9114 5774 (email:firstname.lastname@example.org).