Mass Production of Artificial Seed of the Japanese Common Sea Cucumber (Apostichopus japonicus) in Hokkaido, Japan

Seed production and release of Apostichopus japonicus is a key approach to increase and maintain their natural stocks in Japan. Nevertheless, in many trials conducted mainly in Honshu and Kyushu by the end of the 1990ʼs, the amount of seed production fluctuated annually, and the survival rate of released artificial juveniles was uncertain because of the difficulty of distinguishing them from wild ones. Due to these issues, some hatcheries discontinued A. japonicus enhancement projects. However, due to increase in Chinese demand, the priceof A. japonicus dramatically increased after 2003 in Hokkaido. Facing the decline in the price of sea urchin and abalone, which are major high-value catches in the coastal areas, fishermen were very interested in A. japonicus stock enhancement by releasing artificial seeds. Accordingly, sea urchin and abalone hatcheries in Hokkaido began to produce A. japonicus seed after 2006. This paper will introduce the recent mass production techniques developed in Hokkaido.