ENG-1978 — Page 284

THE ENVIRONMENT

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publication. They are proving very helpful in assessing the relative impact of sewage pollution in these waters.

Work on a preliminary survey of Hong Kong benthos, or sea bottom life, under- taken by the Marine Pollution Section in co-operation with the University of Hong Kong continued. The study of seasonal changes is complete but further analysis is being made of the spatial survey covering more than 200 sites. The survey commenced in summer, 1975.

During 1978 new dumping grounds, in Mirs Bay and the West Lamma Channel, came into use for the disposal of marine spoil from sea-wall construction and reclama- tion projects. Regular monitoring of conditions on these grounds is being carried out as is regular benthos sampling in Tolo Harbour.

On rocky sea bottoms, photographic monitoring of corals and associated marine life is to be used to detect the effects of sewage pollution and dumping. The develop- ment of photographic monitoring was delayed in 1978 until more advanced equipment arrived late in the year.

Monitoring of trace metals in inshore fish and shellfish continued and a major survey was initiated, using the rock oyster as an indicator species. Market sampling was carried out, in co-operation with the Urban Services Department and the Govern- ment Chemist, and the programme concentrated upon high risk species. This approach proved successful in identifying problem areas.

A total of 25 oil spill dispersants were tested for their toxicity to marine life, using rabbitfish and sea urchins as the test organisms.

The Pollution Control Unit of the Marine Department is responsible for dealing with oil pollution problems and the collection of harbour refuse. Under the guidance of a marine officer, staff regularly inspect ships in the harbour receiving oil fuel bunkers, in an effort to prevent oil pollution. They also inspect tankers discharging oil fuel at various terminals, as well as inspecting the oil terminals themselves. Since the unit was established in February, 1971, numerous pollution offenders have been successfully prosecuted. During the year, the maximum penalty for polluting the waters of Hong Kong was increased to a fine of $200,000. The costs incurred in clearing or dispersing the pollution are also recovered from the offenders.

The Pollution Control Unit keeps abreast of technological developments in pollu- tion control, and both Marine Department and Civil Aid Services personnel are continually trained in the operation and deployment of anti-pollution equipment. To combat oil pollution, the unit has at its disposal a purpose-built launch equipped with modern pollution control facilities, stocks of low-toxicity chemical dispersant, oil containment booms and an oil skimming device.

In July, the Pollution Control Unit took delivery of a shallow draft inshore pollu- tion control craft which, although primarily intended and equipped to deal with oil spills close inshore, is fitted with a debris collection device that enables concentra- tions of floating refuse to be removed from the water. In an emergency, 20 government launches fitted with anti-oil pollution equipment can be mobilised and deployed.

Floating refuse continued to be a problem and scavenging services operated through- out the year within Victoria Harbour, Causeway Bay and Yau Ma Tei typhoon shelters, the eastern approaches, Tsuen Wan and Aberdeen Harbour. The refuse collection service for visiting ocean-going ships also was maintained. To cover these