Abalone Mariculture in China‪.‬

ABSTRACT Remarkable progress has been made in recent years in abalone cultivation in China. Beginning in the early 1980s, commercial scale mariculture of abalone has involved 2 species: Pacific abalone, Haliotis discus hannai Ino and the small tropical abalone, H. diversicolor Reeve. Intensive culture of H. d. hannai is distributed mainly in the northern China region, Liaoning and Shandong Provinces with an annual production increasing from about 47 mt (1992) to 4500 mt (2003). The small tropical abalone is the dominant species with a total production of H. diversicolor reaching 3878 mt produced in 2001 in Fujian, Guangdong and Hainan Provinces. Seeds for cultivation are exclusively produced from hatcheries with well-developed technology. Cultivation practices may vary widely among different sea types. Three major forms of grow-out are used in abalone cultivation, land-based tanks, suspended longline cages and intertidal ponds. Abnormal mortality has threatened sustainable development of the abalone industry from its inception. During 1992 to 1996, many facilities in the north ran at a loss due to mass mortality occurring in juveniles and seeds. Mortality usually occurred in the postsettlement nursery phase when spat remain on settlement plates, characterized by cease of dietary intake and falling from the substratum. The cause of this large-scale mortality remains as yet unknown. The same situation occurred in Fujian from 1996, after 2 y of large-scale farming, and has already spread to all other provinces of abalone mariculture. Genetic improvement of abalone has drawn much attention. Hybridization between different populations from Japan and China has been achieved to obtain significant heterosis with growth and survival. Preliminary results on H. d. hannai have shown that survival of selective strains is significantly higher than normal controls. KEY WORDS: Abalone, Haliotis discus hannai Ino, H. diversicolor Reeve, mariculture, seed production, grow-out, disease, abnormal mortality, hybridization, heterosis, selection breeding, marketing, China