Biological Indicator Monitoring in Hong Kong   The Environmental Protection Department (EPD) initiated a biological indicator monitoring programme in 2004 to address the issue of biological effects of pollution in Hong Kong marine waters. This webpage presents the preliminary findings of the 2-year monitoring conducted between 2004 and 2005. It describes the bioindicators adopted in the programme and provides information on biological effects of pollution in local marine waters. Why we need a biological indicator monitoring programme? Bioindicator can be defined as the use of a biological response (e.g. presence, absence or condition of certain species) to indicate environmental changes [Photo of Whiskered velvet shrimp] EPD has been implementing a marine water quality monitoring programme since the mid-1980s. The programme is mainly focused on physical and chemical parameters of water and sediments. Such monitoring is necessary as it provides information on what the pollutants are, where and at what concentrations. But it is difficult to know the effects of pollutants on organisms and ecosystems by simply measuring chemical concentrations in water or sediment. The use of biological indicators fulfills this purpose because it is directly focused on the organisms which we aim to protect. The primary uses of a bioindicator are to characterize current environmental conditions and to track significant change over time. A suite of bioindicators can reveal pollution gradients in the environment, link exposure to adverse biological effects and provide information on the ecological health of marine waters. Incorporating bioindicators into water quality monitoring programmes is now considered to be a more effective way for monitoring marine pollution. Sorting of trawl catch on board  [Photo of Sorting of trawl catch on board]  More on bioindicators Biological indicators used in the monitoring programme  Currently, there is a global trend to supplement chemical and physical measurements with biological and ecological data in monitoring marine pollution. To keep up with scientific advances and track the biological effects of marine pollution, the EPD conducted a consultancy study on the Development of Biological Indicator System for Monitoring Marine Pollution between 2001 and 2003. The study recommended the EPD to implement a bioindicator monitoring programme in conjunction with other water quality monitoring programmes to enhance the effectiveness of water quality management. A suite of 13 bioindicators were found to be useful including Ethoxyresorufin O-deethylase (EROD) in fish liver Lysosomal integrity of mussels Body burden of heavy metals and trace organics in mussels Condition Factor (CF) of fish Hepatosomatic Index (HSI) of fish Gonadosomatic Index (GSI) of fish Fin erosion of fish Epidermal hyperplasia of fish Imposex of gastropods Diversity indices of benthos Log normal distribution of benthos ABC (Abundance and Biomass Comparison) plots of benthos Multivariate statistics of benthos In 2004, EPD initiated a bioindicator monitoring programme. It includes nine bioindicators (1-9 above) which are monitored once a year. Four indicators on biological community (10-13 above) are monitored once every three years commencing in 2006.  Sites and objectives of the bioindicator monitoring programme Taking into account the environmental conditions and spatial gradients in pollution levels, the Hong Kong waters was divided into six zones. Field sampling was carried out in each of the six zones, i.e. Deep Bay (Zone 1), Western Waters (Zone 2), Tolo Harbour & Inner Mirs Bay (Zone 3), Port Shelter & Outer Mirs Bay (Zone 4), Southern Waters (Zone 5) and Victoria Harbour & Junk Bay (Zone 6). Figure: Six zones for bioindicator monitoring in Hong Kong waters. The objectives of the bioindicator monitoring programme are (1) to monitor the biological responses of indicator species with respect to changes in water quality; (2) to compare biological effects/impairments across the Hong Kong waters; and (3) to assess the ecological health of the marine environment. The following presents the initial results of the monitoring carried out between 2004 and 2005 in relation to the first nine bioindicators (1-9 above). Results of the biological indicator monitoring conducted in 2004-2005 EROD in fish liver Lysosomal integrity of mussels Body burden of heavy metals and trace organics in mussels CF, HIS and GSI of fish (3 indicators) Fin erosion and epidermal hyperplasia of fish (2 indicators) Imposex of gastropods Preliminary conclusions

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