THE ENVIRONMENT
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information at various stations. Tide levels recorded at all tide stations were analysed with a view to refining tidal predictions in Hong Kong.
To monitor earthquakes and seismicity, a network of three short-period seismometers operates at Cheung Chau, High Island and Tsim Bei Tsui. Long-period seismographs record tremors from all over the world. Strong-motion accelerographs operate at two locations with different soil properties. About 150 earthquakes are detected annually with epicentres within 320 kilometres of Hong Kong.
The observatory operates a caesium beam atomic clock which provides time signals. accurate to fractions of a microsecond. A six-pip signal is relayed to Radio Television Hong Kong for transmission.
Environmental Problems
Hong Kong, as a major commercial centre, has inevitably suffered the environmental consequences of industrial development and economic growth. As the Governor stated succinctly at the opening of the 1988-9 session of the Legislative Council, 'One unfortunate by-product of our economic success and population growth has been serious environ- mental pollution . . . I am increasingly convinced that one of our major priorities must be to halt this decline and to do more to improve our environment.'
Water and Wastes
Over the year, the indiscriminate dumping of refuse and the discharge of sewage and trade - effluents into coastal waters has marred Hong Kong's image as a beautiful seaport. These effluents and wastes are rich in organic matter which robs the water of its oxygen, causing stagnant, smelly conditions, and also contain nutrients which encourage the development of algal red tides. Unfortunately, some of the red tides are caused by microscopic algae that produce paralytic shellfish poisons. These toxins were detected in some local shellfish during the year and the public were warned not to eat them.
Many of the fast-developing industries, such as textile dyeing and electroplating of metals, discharge harmful effluents into streams and surrounding waters. This endangers marine life and may contaminate the food chain. Further pollution of the waters is caused by the illegal connection of effluent sources to storm-water drains rather than to foul sewers, often causing the drains to become badly corroded.
The New Territories suffer widespread pollution due to livestock waste. Pig and poultry wastes are discharged into streams and rivers, forming an unsightly crust on the surface. Besides the foul smell and unsanitary conditions, the encrustation blocks drains and watercourses, thereby aggravating the flooding of low-lying plains during the rainy season.
Households and industries in Hong Kong all generate enormous quantities of solid and semi-solid wastes, ranging from domestic refuse and sludges to construction waste and coal ash. The rate of production of all these wastes is expected to continue to increase. These wastes pollute not only the land and water, but also the atmosphere which serves as a receptacle for pollutants like construction dust and exhaust fumes from refuse incinerators. The growing amount of chemical and clinical wastes, decomposing carcasses and other organic matter also poses a formidable task for disposal.
Air
The air quality of Hong Kong is deteriorating, the main causes being the exhaust fumes from incinerators, power stations, factories using high sulphur fuel, and smoky vehicles. In certain weather conditions, the fumes discharged from chimneys form indispersible plumes which frequently result in a layer of brown smog over the city.