Chapter 2

From Fisheries Toward Aquaculture

Guangbin Liu* Jingchun Sun┼ Shilin Liu┼
*    Benthic Biology Research Centre, Marine Biology Institute of Shandong Province, Qingdao, Shandong, PR China
┼    Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, Shandong, PR China

Summary

In China, Apostichopus japonicus has a long history of consumption, owing mainly to the health benefits and medicinal properties attributed to sea cucumber. The traditional dive-fishing method for A. japonicus is still being used in China today. With the socioeconomic boom in the 1990s, the market demand for sea cucumber increased considerably and led to the sharp decline of natural resources. Consequently, A. japonicus aquaculture emerged and became the most important source of A. japonicus on the market. With increasing wealth and consumer demand in China, A. japonicus aquaculture is expected to expand in years to come, despite limiting factors, such as diseases, environmental deterioration, and space constraints.

Keywords

aquaculture development Apostichopus japonicus fishing history limitations sea cucumber trends

2.1. The history of A. japonicus fishery

2.1.1. Early mentions and fishery

The earliest records of sea cucumbers appear in a book called (Adversaria of Monster by Sea-shore) (published between the years 268 and 280), which was written by Shen Ying during the period of the Three Kingdoms (see Table 1.1 in Chapter 1). "The meat looks like black soil, the diameter of a child's arm, about five cubits long, with the abdomen in the middle and thirty tube feet around the body, without mouth and eyes, and it can be cooked." The black soil meat refers to sea cucumber. In (The Ode to Rivers) written by Guo Pu (276-324) during the Eastern Jin Dynasty, it was on a par with other prized food, such as pen shell meat. Sea cucumber was rarely referred to for a long period of time after that, until it was noted again by Jia Ming in (Preliminary Instructions for Food) (ca. 1367) during the Yuan Dynasty: "Sea cucumber tastes sweet and salty." More records emerged subsequently, such as in (Drug Discrimination) (by Du Wenxie during the Ming Dynasty, ca. 1598), (Five Miscellaneous) (by Xie Zhaozhe during the Ming Dynasty, ca. 1616), (Fujian Note) (by Zhou Lianggong during the Ming Dynasty, ca. 1647-1672), and (New Compilation of Materia Medica) (by Wu Yiluo during the Qing Dynasty, ca. 1757). Those documents narrate the habitat, appearance, and restorative function of sea cucumber, without any references to fisheries. In 1765, (A Supplement to Compendium of Materia Medica) (by Zhao Xuemin during the Qing Dynasty) noted the harvesting of sea cucumber in Guandong, Penglai, Fushan, and mentioned the time, process, and skill required to fish them. According to the ecological characteristics and geographical distribution of different species of sea cucumber in China (Liao, 1997), the sea cucumber mentioned in the latter book is A. japonicus. We can therefore conclude that a dedicated fishery for A. japonicus was established no later than the middle of the eighteenth century. See Chapters 1 and 20 for more details on the long-standing cultural and culinary traditions surrounding sea cucumber in China.

2.1.2. Fishing techniques

In the book A Supplement to Compendium of Materia Medica, it is recorded that Han Ziya in Guandong said "once they find the sea cucumbers, they dive in the water to capture them ... divers explore and catch sea cucumbers by hand, placing them around their neck, under their armpits, or between their legs," and Li Jinshi of Penglai records said "sea cucumber also can be found in shallow sea of Dengzhou, ... mostly crawling on big stones, in areas too deep to be captured. The people spread seal oil on the surface of the water, when it disperses, the water surface becomes clear enough to see through it to localize and catch sea cucumber. The harvesters are attacked by sharks constantly, thus increases the value and cost of sea cucumbers." It is also recorded that Chen Lianghan of Fushan said "the sea cucumbers lurk on the bottom of the ocean in March and April ... reproducing and therefore easy to capture; ... It is difficult to catch sea cucumbers when they move to the deep and attach firmly to rock in May and June; . During canicular days, the sea cucumbers hide under rocks or in the mud in deeper areas and are harder to harvest; ... During hibernation, sea cucumbers migrate to the bottom of the deep sea and cannot be caught." The traditional dive-fishing method for A. japonicus is still being used in northern China, the only difference being that the diver's equipment and the containers for storing the sea cucumbers have been improved (Zhang and Wu, 1955). In general, divers leave the boat, seek A. japonicus visually between 2 and 20 m depth, and then collect them by hand and store them in mesh bags tied to their waist. The bags are made of nylon or polypropylene rope, with a mesh size of 0.5-1.0 cm, a length of 60-80 cm, an opening diameter of 15-20 cm, and a bottom diameter of 40-50 cm. The divers work underwater for about 1-2 h, less in winter when lower water temperatures prevail. At the same time, workmates on the boat monitor the air supply, and sort the harvest that divers bring back at regular intervals (Figure 2.1). There are currently two different operating methods for harvesting A. japonicus in China: (1) the so-called hookah method, which involves an airline fed by a compressor, providing unlimited air supply but allowing a limited range of activities for divers; (2) free diving, allowing free movements, but limited time underwater. Figure 2.1 The traditional dive-fishing method for harvesting A. japonicus in northern China. (A) Diver leaving the boat in search of sea cucumbers, using a hookah as air supply. (B) Diver bringing back a bag full of A. japonicus. (C) Technicians sorting the harvest aboard the boat. (D) A sample of A. japonicus collected at about 10 m depth. Photos by Guangbin Liu The sea cucumber fishery is a traditional industry operated by coastal fishermen in China. As far as 1681, fishermen went around to the Xisha and Nansha islands fishing grounds for sea cucumbers, such as Thelenota ananas and Holothuria nobilis; since then, fishery has never stopped, according to historical records. Sea cucumber fishing in the early days, mainly depending on free diving, was inefficient, and did not allow to harvest beyond 20 m depth; it did not involve large sea cucumber specimens found mainly in deep water. The cucumber-fork was invented in the 1920s to collect cucumber species in the Nanhai Sea (Li, 1990). There is no similar fishing tool used to collect A. japonicus in historical records; people still harvest A. japonicus by hand in China.

2.2. Aquaculture development

It has been about a thousand years since people started to explore and utilize A. japonicus in China (see Chapter 1). However, the aquaculture of A. japonicus emerged only in the past century. Early as 1954, Zhang Fengying and his collaborators tried to culture A. japonicus on an artificial reef in Beidaihe, Hebei Province (China) and obtained good results. Due to the poor living standard at that time, the nutritive value of sea cucumber was not widely recognized and market demand was limited. Natural resources of A. japonicus were abundant and could easily satisfy market needs, precluding the need for any aquaculture industry to develop. With the socioeconomic boom in the 1990s and the ever-growing evidence of health benefits associated with the consumption of A. japonicus, the market demand increased significantly, which led to excessive harvest of wild A. japonicus. It became almost extinct in several areas of its native distribution range during the same period. In the 1960s, A. japonicus fishing output was 260-280 t in Shandong and Liaoning Provinces, but it sharply dropped to 60-80 t by the 1970s (Zhang and Liu, 1984). As the natural stocks of A. japonicus could no longer satisfy the growing market, A. japonicus aquaculture emerged.

2.2.1. Artificial production of seedlings

In 1953, Zhang Fengying, from the Institute of Oceanology, Chinese Academy of Sciences, in collaboration with the Fisheries Research Institute of Hebei Province, conducted the first research project on the breeding of A. japonicus and obtained the first artificially bred juveniles of the species (Zhang et al., 1958). In the mid-1980s, the Fisheries Research departments in Hebei, Liaoning, and Shandong provinces established an industrial breeding program for A....