Newsletter No. 24

CUHK Newsletter- No.24 November 1991 Dr. K. H. Chu 一 The Shrimp Specialist Long before he returned from abroad’ Dr. K. H. Chu had specialized in the study of lobsters and crabs. Since joining The Chinese University, he has added the study of the growth of shrimp larvae to his list of interests. Is he 'obsessed' with shrimps and crabs? ' Not really,' he replies with a smile. ' My present research project was initiated by the previous assistant director. Dr. W. Y. Tseng. But it is true that I like to study shrimps,' he adds. In Asia there is a booming shrimp culture business at the moment, but it is often constrained, as Dr. Chu explains, by the lack of supply of shrimp larvae. It takes roughly 12 days for a fertilized egg to develop into a larva, during which time the shrimp undergoes tremendous physiological change, each stage requiring different kinds of nutrients. In order to ensure a constant supply of shrimp larvae. Dr. Chu analyses their body structure, function, physiology, food-taking habits and mortality rates. All of this is vital to minimize the mortality of the shrimps in the most complicated phase of their lives. The laboratory has successfully cultured five to six species of shrimp larvae. Both local and overseas businesses have placed orders for such species from the laboratory. However, trade with local people has declined with an overall decline of the shrimp culture business in Hong Kong, while the export of shrimp larvae is usually handicapped by severe import regulations. When Dr. Chu first joined the laboratory, shrimp larva culture was still in its infancy. To have contributed so much to the development of the technique to its present advanced stage has given him much satisfaction. His research continues with the study of moulting and ovarian maturation in the female, in the hope of achieving total control over the culture process. Furthermore, Dr. Chu and his colleague Dr. C. K. Wong are currently engaged in a three year joint project with the Institute of Oceanography of the South China Sea, Academia Sinica, to analyse the species, location, and output of shrimps in the water where the Zhujiang (Pearl River) meets the sea. Dr. C. K. Wong 一 Marine Plankton Ecologist Dr. C. K. Wong specializes in the ecology of marine plankton, and its use in monitoring the degree of pollution of Tolo Harbour. As he explains, the quality of water in the harbour has been deteriorating since sewage from nearby poultry farms is being dumped into the water, causing algae to multiply. As the algae decompose, they use up the available oxygen in the water, and this has encouraged the growth of the ‘red tide’ organisms at the expense of all other living organisms in the harbour. Although Tolo Harbour is now full of stagnant water, and it has become very difficult to find specimens, Dr. Wong still routinely makes a specimen collecting trip every month. As the laboratory's research launch is small, it is not possible for Dr. Wong to sail far out to the sea, and although night time is the best time to collect marine plankton. Dr. Wong is usually hesitant about making night trips because of the presence of many smuggling boats in Tolo Harbour after dark. Despite these problems. Dr. Wong decided to venture out on a longer trip last July, and he hired a larger junk for the purpose. At about seven o'clock that July evening, even though the summer sky was still bright, the smugglers were already at work. Having spotted Dr. Wong's junk, the smugglers sent a small scouting boat to check it out. The crew even boarded the junk, but left after a cursory search had revealed nothing of any interest to them. Dr. Wong recalls that a police patrol boat was only a few hundred yards from the scene, but he and his crew kept silent and no one was hurt. This was undoubtedly the most dangerous experience in his four years with the laboratory. Dr. Wong hopes that it was a once-in-a-life-time experience, and refuses to allow it to prevent him from carrying out the work which he loves, in an environment which he finds much more peaceful than the main campus. His only complaint? The awful smell of the red tide! 6