Tolo Harbour and Channel
The Tolo area (~50 square km), situated in northeast Hong Kong, consists of a shallow, semi-estuarine inner harbour (Tolo Harbour), which deepens to a narrow tidal channel (Tolo Channel) opening into Mirs Bay in the South China Sea and water depth increases from ~5 m in the inner harbour to ~20 m in the Tolo Channel. The Tolo Harbour often suffers from hypoxia in summer due to its semi-enclosed topography which result in low flushing rates in Tolo Harbour.
The area was once a royal enclosure for pearl culture dating back to the Sung Dynasty, and was only discontinued in the early eighties when a number marine fish culture zones were established . The area surrounding the area was formerly with extensive Mangrove stand along the shoreline, but 42% of the mangrove and 22% of natural shoreline were lost as a result of reclamation works due to the development of Shatin and Tai Po new towns since the 1970s.
The Tolo Harbour was once heavily polluted with untreated sewage and livestock waste in the 1970-80s, and after a number of mitigation measures taken by the government from the 1980s, the water quality of the Tolo area has been improving over the past decades. However the marine organisms in the area are still affected by past contamination, increasing organic compounds in the sediment, and episodic hypoxia events in summer, and hence the marine ecosystem in the area may take a long time to ‘recover’.
In recognition of the undoubted ecological and scenic value of the Ting Kok SSSI, the Hong Kong SAR Government has proposed the Ting Kok Coastal Conservation Plan (Ting Kok+) in 2012.
The Environment Bureau (ENB) has been leading an inter-bureaux and departmental initiative to implement this process, as well as to engage stakeholders who can share their views and expertise. After a series of meetings, the Government and the stakeholders (including Tai Po residents, fishermen, academics and green groups) agreed that there was an urgent need for a comprehensive survey to assess the current status of the biodiversity and ecology of marine organisms in the Ting Kok SSSI and its surrounding areas. The stakeholders acknowledged that such a study needed to include the whole Tolo area as marine communities within this enclosed, almost discrete, area are inevitably inter-connected.
This project is one of the core initiatives recommended in the Ting Kok+.