Although the study group was not able to visit any marine aquaculture centres, it was briefed on the activities in this field by Mr. Li Kemin, Head of the Marine Aquaculture Division of Guangdong Aquatic Products Bureau. Compared to freshwater fish farming, marine aquaculture is a very recent development in the country. It is still in the early stages of development, even though production of certain species like oysters and seaweeds has become substantial. All coastal provinces in China undertake marine aquaculture now, but Shandong and Liaoning Provinces are more advanced in this field. Production in 1977 was quoted as about 11 000 t and in 1978 was 12 000-13 000 tonnes.
In Guangdong Province alone over 120 000-130 000 mu of coastal waters are used for oyster farming. Bottom culture on rocks or on cement concrete slabs planted in regular rows on mud flats are used for oyster culture. Production is reported to be 300-500 jin of shucked meat per mu by rock culture and 1 000-1 500 jin per mu by slab culture. Pearl cultivation is also undertaken on a small scale by the hanging method of pearl oyster farming. Cockle farming is done on a small scale. The area utilized and production obtained are small, but income is relatively high as most of the cockles are exported to Hong Kong. Besides collection of spat, planting and protection of the environment are the major activities related to shellfish farming. The culture of different species of seaweed is expanding, but the production varies very considerably, depending on the species and area where cultivated. Shrimp culture experiments have been started in recent years, but the prevalent practice is similar to the maintenance of "trap ponds" where juveniles are allowed to enter and grow to marketable size. In a few places along the coast young crabs are also collected and grown in ponds.
Marine aquaculture is carried out by state farms or communes and production brigades, either as the main or sideline occupation. Obviously this is an area of aquaculture in which China is not very advanced and has a lot to learn from other countries.