ENG-1978 — Page 308

NATURAL HISTORY

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Since it was introduced to Hong Kong in 1938, the African Giant Snail has become a major pest in vegetable crops and gardens. But in 1977, and again in 1978, the snails were late in emerging after the winter and were reported in much lower numbers than in previous years. Weather conditions in the first half of 1978 also inhibited some of the six other species of snails that are common vegetable pests. Farmers are troubled by several slugs; one of these - Veronicella – is a large black slug sufficiently different from all other slugs to be placed in a separate family.

Aquatic Life

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Recent excavations at Sham Wan, Lamma Island, by the Hong Kong Archaeological Society have uncovered significant quantities of fish bones, mainly of the head grunt (Pomadasys hasta) and marine catfish (Arius leiotetocephalus), some of which date back 4,000 years. This discovery, together with similar finds of shells, is the first direct evidence of food remains in this area, indicating human exploitation of marine resources, presumably by coastal settlers. Considering the necessarily primitive nature of fishing gear and methods in those times, when judged by present standards, the relative abundance of these species (which today continue to be commercially utilised) indicates that these large fishes were readily available to early settlers.

Marine life is an important natural protein source for the people of Hong Kong. The recent estimate of a per capita fish consumption of about 50 kilograms illustrates the popularity and prevalence of this type of animal protein.

Towards the end of February, 1978, three species of marine mammals were recorded in Hong Kong waters. They were a dead female lesser rorqual (Balaenoptera acutorostrata) stranded on Lai Chi Wo beach, a dead female euthrosyne dolphin (Stella euthrosyne) in Aberdeen, and a dead male black finless porpoise (Neomeris phocaenoides) in Tolo Harbour.

Flora

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The Hong Kong Herbarium celebrated its centenary during the year. This government institution contains a collection of about 33,000 plant specimens and is responsible for collecting, classifying and maintaining authoritative preserved plant specimens representative of Hong Kong flora. It also disseminates knowledge and information about the flora of Hong Kong and maintains an index of scientific, Chinese and English common names for the plants of Hong Kong. The herbarium, situated at the headquarters of the Agriculture and Fisheries Department in the Canton Road Government Offices in Kowloon, is open to the public.

A Hong Kong Herbarium Centenary Exhibition was jointly presented by the Urban Council and the Agriculture and Fisheries Department at the Hong Kong Museum of History. The exhibition displayed specimens and photographs to show the history and development of the herbarium, its work and function, and botanical discoveries in Hong Kong. It attracted a good attendance.

For so small an area, Hong Kong has a large and diverse flora. The territory is situated near the northern limit of the distribution of tropical Asian flora. It is estimated that there are about 2,500 species of vascular plants, native and introduced. Except for the most recent discoveries, these are listed in the Check List of Hong Kong Plants (Agriculture and Fisheries Department). The 1974 edition was updated