Results

2001-02 monitoring period

The benthic infauna, being one of the major food sources to the waterbird, were low in diversity and were dominated by a few pollution-tolerant species. The phenomenon was in line with the results of water and sediment quality analyses.

There were 54,720 birds recorded in Deep Bay during the winter of 2001-02. A peak count of 51,333 was made in January 2002 and 39,249 of them were found in the Ramsar Site. The figures are comparable to the records obtained in recent years.

Water pollution was detected from monitoring stations at Shenzhen River, Shan Pui River and gei wais. High levels of nutrients were detected and dissolved oxygen was reduced as a result. Algal bloom was recorded in gei wais and had implication in the current management of the gei wais. A relatively high loading of mercury in sediment was detected as compared with the reference stations of the EPD. Total DDT, total PCBs and total PAHs in most of the samples were below the action levels. Regarding sedimentation rates over the intertidal mudflat, both erosion and sedimentation were observed at different time and location. It showed that the intertidal mudflat was a dynamic environment.

The extents of habitats of the Ramsar Site were monitored using satellite image analysis. The intertidal mangal expanded from 262 to 280 hectares during the monitoring period. The major extension was located at the northern end of the mangal and was about 10 ha in size.

The finding of the 2001-02 monitoring period is summarized in the executive summary (PDF Format) of the project.

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