Eutrophication Studies on Tolo Harbour, Hong Kong

Tolo Harbour is an almost land-locked waterbody with only one narrow marine inlet to the open sea at Mirs Bay in the Eastern Waters of Hong Kong. Due to its enclosed nature, the waste assimilative capacity is very limited. Besides, it receives substantial pollutant loads from the two sewage treatment plants in the Tolo catchment, livestock rearing industry and other industrial discharges. The building-up of the organic matter and nutrients in the Harbour has caused an increasing occurence of red tides in the past decade. This paper describes the trophic status of the Tolo Harbour based on the monitoring stations results obtained from the Hong Kong Government with particular reference to the chlorophyll-a, secchi depth, total nitrogen (TN) and total phosphorus (TP) concentration.