Spatio-temporal Distribution of Chlorophyll-a Concentration in Hong Kong''s Coastal Waters
香港海域叶绿素-a浓度的时空分布规律

Seven Water Control Zones in Hong Kong's coastal waters with sampling data of 17 parameters collected at 37 monitoring stations from 1988 to 1999 were selected to analyze the spatio-temporal variations of chlorophyll-a concentration. The results suggest that frequent red tides occurred in eastern Hong Kong's coastal waters, and less red tides occurred in an estuarine environment in the west. In all coastal waters, the organic contents indicator, BOD 5 , was a common significant influential factor of the chlorophyll-a level. Nitrogen and light penetration condition related to turbility, total volatile solids and suspended solids had greater influence on the cholophyll-a level in the east than in the west, while phosphorus and oceanographic condition associated with salinity, temperature, dissolved oxygen and pH was more important in west than in east. Generally, there was a higher average chlorophyll-a level in the late winter and early spring, and late summer and early autumn in a year. The chlorophyll-a level was higher in the east than in the west among all seasons in general. The chlorophyll-a concentration has a fluctuation period of 8-10 years generally in the whole region.