 | Epinephelus awoara Epinephelus akaara |
CULTURE PRACTICES
Culture of groupers in floating netcages is a developing sector of the seafarming industry. The size of the netcages varies considerably according to the environmental conditions prevailing in the culture area. Common sizes are 2×2 m and 4×4 m with a depth of 2–5 m. Polyethylene and nylon are used as the netcage material. The former is more popular as it is lighter and cheaper. The netcage frame is usually made of steel tubes, although cheaper materials such as wooden beams or bamboo poles are often used. Plastic containers (100x70 cm) or discarded petrol drums are used as buoys to keep the netcage afloat. Anchors weighing 100 kg each keep the rafts in position. The initial stocking density mainly depends on the size of the fingerlings. The groupers are fed on chopped fresh or frozen trash fish and reach the marketable size of 600–800 grams in 8–10 months. Feeding rate is usually three times a day for fingerlings while larger fish are fed twice daily. Grouper is a highly valued species among the Chinese, however most of the national production is exported. Hongkong is a major export market.
PRODUCTION
HISTORY
Two species of grouper are cultured in China: Epinephelus awoara and E. akaara. Groupers are mainly distributed in the South China Sea and constitute one of the most important finfish groups in the mariculture industry. Although grouper culture was first attempted over a decade ago it has developed only on a small scale. The supply of fingerlings is the major constraint to the further expansion of this seafarming activity. At present grouper fry are collected entirely from the wild as artificial breeding has not yet been successful. In 1987 over 10,500 MT were produced.
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  |
| E. awoara & E. akaara | ||
| Source of seed | Artificial | |
| Culture method | Floating netcage | |
| Yield/ha | NA | |
| Market | Export | |
| Production area | NA | |
| Status of culture | Developing | |
| Major constraints | High initial investment Limited fry supply | KEY MAP |
 | Pagrus major Sparus macrocephalus |
CULTURE PRACTICES
Culture of seabream in floating netcages is a developing sector of the seafarming industry. The size of the netcages varies according to the environmental conditions prevailing in the culture area. Common sizes are 2×2 m and 4×4 m with a depth ranging between 2–5 m. Polyethlene and nylon are used as the netcage material, however the former is more popular as it is lighter and cheaper. The netcage frame is usually made of steel tubes, although cheaper materials such as wooden beams or bamboo poles are often used. Plastic containers (100×70 cm) or discarded petrol drums are used as buoys to keep the netcage afloat. Anchors weighing 100 kg each keep the rafts in position. Seabream are fed on artificial feed or chopped fresh trash fish and reach the marketable size of 600–800 grams in about 2 years. Feeding rate is usually done twice daily and it takes 8 kg of trash fish to produce 1 kg of seabream. Seabream is a highly valued species among the Chinese, but a large proportion of the national production is exported. One major export market is Hongkong.
PRODUCTION
HISTORY
Of the two species cultured in China, Pagrus major is the more popular one. Seabream are found along the entire coastline of China and are one of the most important finfish groups in the mariculture industry. The culture of seabream started almost 10 years ago, while artificial fry rearing succeeded in the mid-1980's. Due to the high market price of this marine fish its culture has expanded considerably in the Fujian, Guangdong and Hainan provinces. In northern China however, it is done on an experimental scale due to the low water temperatures occurring in winter months.
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  |
| P. major & S. macrocephalus | ||
| Source of seed | Artificial | |
| Culture method | Floating netcage | |
| Yield/ha | NA | |
| Market | Export | |
| Production area | NA | |
| Status of culture | Developing | |
| Major constraints | Limited fry supply High initial investment | KEY MAP |
 | Mugil cephalus Mugil so-iuy |
CULTURE PRACTICES
Mullet is a euryhaline fish and is found in sea, brackish and fresh waters. Pond culture is practiced mainly in southern China, while in the northern provinces they are polycultured with other marine organisms such as shrimp. The ratio of mullet and prawn is about 5:95. Spawning season for M. cephalus is in December and natural fingerlings are found from February to March. In Shandong province the spawning season for M. so-iuy is in May and the fingerlings appear in early June. A major research advance in mullet culture is the use of LHRH-a and CPH to induce broodstock maturation and spawning. Mullet are cultured in 0.2–1.0 ha ponds and the fingerling size is usually in the range of 3–12 cm. In monoculture the stocking density ranges from 22,500–60,000/ha, while in polyculture the density ranges between 2,000–5,000/ha. The culture period for M. cephalus is 1–2 years and 2–3 for M. so-iuy. The market size for both species is 0.5–1.5 kg. During the grow-out phase mullet are fed with soybean and peanut cake. As algae constitute its major food item the culture ponds are regularly fertilized with organic manure and chemical fertilizers.
PRODUCTION
HISTORY
There are two species of mullet cultured in China: Mugil cephalus and Mugil so-iuy. The former is mainly distributed in the East and South China seas, while the latter is mainly found in the Yellow and Bohai Seas. In southern China mullet culture is practiced in earthen ponds. Research on artificial fry rearing was first attempted in the late part of the 1950's but the technology was developed only three decade later. However, due to the low market price the culture of mullet has expanded rather slowly. Major culture areas are in Liaoning, Shandong and Jiangsu provinces.
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  |
| M. cephalus & M. so-iuy | ||
| Source of seed | Artificial and wild | |
| Culture method | Pond | |
| Yield/ha | NA | |
| Market | Domestic | |
| Production area | NA | |
| Status of culture | Developed | |
| Major constraints | Limited suitable areas Environmental pollution | KEY MAP |
 | Paralichthys olivaceus Limanda yokohamae Cynoglossus semilaevis |
CULTURE PRACTICES
Culture of flounders in floating netcages is a developing sector of the seafarming industry. Preliminary work on the ongrowing methods have been carried out by the Yellow Sea Fisheries Research Institute (YSFRI) in Qingdao (Shandong province). The size of the netcages varies considerably according to the environmental conditions prevailing in the culture area. However, common sizes are 2×2 m and 4×4 m with a depth ranging between 2–5 m. Polyethylene and nylon are used as the netcage material. The former is lighter in weight and cheaper. The netcage frame is usually made of steel tubes, although cheaper materials such as wooden beams or bamboo poles have been used. Plastic containers or discarded petrol barrel are used as buoys to keep the netcage afloat. When hatchery produced fingerlings are about 10 cm long they are transferred to the floating netcages for ongrowing. The flounders are fed on chopped fresh or frozen trash fish and reach the marketable size of 700–800 grams in 2 years. Feeding rate is usually three times a day for fingerlings and twice daily for larger fish.
PRODUCTION
HISTORY
Most of the commercially valuable flounders harvested in China are mainly distributed in the Yellow and Bohai seas. Flatfish, particularly the Japanese flounder (Paralichthys olivaceus) are important economic species. Chinese scientists began researching on the artificial breeding of flounder in the early 1970's and succeeded to develop a technology in the early 1980's. Although breeding know-how is presently available flounder culture is still practiced on a small scale. Major constraints are the limited availability of suitable culture sites and high initial capital investment.
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  |
| P. olivaceous & C. semilaevis | ||
| Source of seed | Artificial | |
| Culture method | Floating netcage | |
| Yield/ha | NA | |
| Market | Export | |
| Production area | NA | |
| Status of culture | Developing | |
| Major constraints | Limited fry supply Limited suitable areas | KEY MAP |
 | Saccostrea cucullata Crassostrea rivularis Crassostrea gigas |
CULTURE PRACTICES
Three basic culture methods are practiced in China: bottom, stake and hanging culture. Bottom culture is mainly practiced in intertidal areas. Stones and/or a variety of concrete structures are placed onto the seabed for spat to settle on. Growth period ranges from 7–12 months and yields vary from 30–80 MT/ha. Bamboo stake culture is widely practiced in Fujian province. Stakes 1.2 m long are laid down in bundles (4–5 stakes/bundle) in mid-tidal flats just before the spatfall peaks. The bundles are regularly spaced in rows and 150,000–180,000 stakes a hectare are normally used as collectors. Oyster spat settling in May reach marketable size in 11– 15 months, and those in September, 16–18 months. Yields vary from 60– 110 MT/ha. Floating raft or long-lines have gained popularity in recent years and are used in areas with a water depth of 5–10 m. Raft culture produces a higher yield in a shorter period than bottom culture. A raft of 80 sq. m. produces the same yield in 2 years as 670 sq. m. of bottom culture does in 4 years. The oyster industry in China is well developed, however, some degree of mechanization is required to raise output.
PRODUCTION
HISTORY
Chinese fishermen, particularly the ones in the southern provinces (eg. Fujian and Guangdong), started oyster farming almost 2,000 years ago. At present there are 42,000 hectares of oyster culture area. In 1988 production of fresh oyster meat was 74,954 MT. Oysters are mainly cultivated in Guangdong, Fujian and Zhejiang provinces. In northern China oyster culture has been developing rapidly in recent years due to the high market price. Almost all of the spats are collected from the wild except for a few non-endemic species which have been imported from abroad such as the Pacific oyster, Crassostrea gigas
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  | |
| C. gigas & C. plicatula | |||
| Source of seed | Artificial | Wild | |
| Culture method | Bottom & rack | Bottom & hanging | |
| Yield/ha | 1.8 MT/ha | ||
| Market | Domestic | ||
| Production area | 42,000 ha | ||
| Status of culture | Developing | ||
| Major constraints | Limited seed supply Environmental pollution | KEY MAP | |
 | Pinctada fucata martensis Pinctada chemnitzii Pinctada maxima Pinctada margaritifera Pteria penguin |
CULTURE PRACTICES
Several species of pearl oysters exist in China, however Pinctada fucata martensis is the most widely used. The culture methods of pearl oysters is similar to the ones used for culturing edible oysters and mussels. Rack, bottom and hanging methods are all practiced. There are two forms of hanging culture: raft and long-line. Rafts are constructed from bamboo poles and usually measure 8×6 m. Raft can be single or connected with others to form a multiple raft system. Each raft is kept in position by four heavy anchors fixed at each corner. The long-line is kept in position by two anchors at each end and are usually about 20 m in length. Buoyancy arrangements depend on the local conditions, loading and degree of fouling. The netcages (usually pearl nets) containing the operated oysters are hung from main rope vertically at different depths depending on the environmental conditions of the culture site. The pearl nets can be pyramidal or conical, however the latter is preferred as it prevents bunching of the oysters in the corners. Culture sites are selected in areas where there is a constant water flow and are sheltered from strong winds and waves. The water depth must never be less than 3 m.
PRODUCTION
HISTORY
Pearl oysters are mainly cultured in the southern provinces of China: Guangdong, Hainan and Guangxi. Chinese fishermen knew the technique of culturing pearl oysters almost 1,000 years ago. However, pearl culture based on scientific knowledge has only been practiced in the last 2–3 decades. It was during this period that artificial production of spats became possible, as well as nuclei implantation into the gonad region of mature oyster. Although China is a major pearl producing country further expansion is limited by the lack of skilled labour. It is estimated that about 1 MT of pearls are produced annually.
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  | |
| P. martensis & P. chemnitzii | |||
| Source of seed | Artificial | ||
| Culture method | Raft | ||
| Yield/ha | NA | ||
| Market | Domestic and export | ||
| Production area | NA | ||
| Status of culture | Developing | ||
| Major constraints | Limited skilled workers | Limited suitable areas | KEY MAP |
 | Mytilus edulis Perna viridis |
CULTURE PRACTICES
Three basic culture methods are practiced in China: bottom, rack and raft culture. Rack culture, which is most suitable in shallow areas with a water depth of 1–2 m, is composed of a wooden frame structure. The mussel culture rope are then hung from the horizontal poles. In bottom culture, sites have gravelly or rocky substrates (in muddy bottoms the mussel clusters tend to sink or become covered with silt). Floating raft has been found to be the most suitable method for culturing mussels in deep waters. Rafts are commonly made of bamboo poles fixed together with ropes and kept in position by heavy anchors. Long-line culture is also practiced. The lines are usually 60 m in length depending on the environmental conditions of a particular site, while the length of the mussel ropes is determined by the depth of the water and degree of buoyancy of the long-line. The adoption of more intensive culture systems has been responsible for the increase of mussel landings in recent years. A major constraint to this culture activity is the low market price and environmental pollution.
PRODUCTION
HISTORY
In 1958, Chinese scientists began to research on methods and techniques on how to gather mussel spat under controlled conditions. Several years later encouraging results were achieved in seedling rearing and culture on a commercial scale. It was in the early 1970's that mussel culture started to expand considerably. Although there has been a gradual growth in the last decade, mussel culture in the last few years has been receiving less attention due to the low value of mussel compared to other mariculture species such as scallop and shrimp. Total production in 1988 was 429,675 MT with culture area of 4,000 ha.
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  | |
| M. edulis & P. viridis | |||
| Source of seed | Wild and artificial | ||
| Culture method | Bottom (stone) and raft | ||
| Yield/ha | 107 MT/ha | 100 MT/ha | |
| Market | Domestic | ||
| Production area | 2,000 ha | ||
| Status of culture | Developing | ||
| Major constraints | Low price Environmental pollution | KEY MAP | |
 | Anadara granosa Anadara inflata Anadara subcrenata |
CULTURE PRACTICES
Cockles are cultured on the bottom, however, A. inflata have been experimentally cultured in cages. The blood cockle or A. granosa is usually cultured in intertidal areas with muddy bottoms. Chinese fishermen often construct dikes around the culture site in order to reduce the period of air exposure during low tides. By doing this the cockles have a longer feeding period and therefore tend to grow faster. A. inflata and A. subcrenata are usually cultured in deeper water. In natural conditions, cockles tend to spawn 4–5 times annually. The spawning season varies depending on locality. In Shandong province the main spawning season occurs between July and August, from June to August in Zhejiang and between August and October in Fujian. Cockle specimens with a shell length of about 3 cm can release up to 3.5 million eggs. Cockle cultured for one year usually attain a shell length of 2 cm while 2–3 years are required to reach the commercial size of 3–3.5 cm. Major constraints to the cockle culture industry are limited seed supply, limited suitable culture areas, poor quality control and environmental pollution.
PRODUCTION
HISTORY
There are several species of cockles cultured in China. Among these Anadara granosa have the longest culture history particularly in Fujian and Zhejiang provinces. With regard to the artificial rearing of spat some encouraging results were first obtained in the early 1980's but little progress has been made since. Culture of Anadara inflata and Anadara subcrenata was initiated on a large scale 3 years ago and it is carried out in the southern provinces of the country. Spat of A. inflata are collected from the wild and have been artificially produced since 1982. The production in 1988 was 33,986 MT with a culture area of 6,700 ha.
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  | |
| A. granosa & A. inflata | |||
| Source of seed | Wild | Wild & artificial | |
| Culture method | Bottom | ||
| Yield/ha | 0.5 MT/ha | ||
| Market | Domestic | ||
| Production area | 3,700 ha | 3,000 ha | |
| Status of culture | Developing | ||
| Major constraints | Limited seed supply Limited suitable areas | Environmental pollution Poor quality control | KEY MAP |
 | Meretrix meretrix Meretrix lusoria Meretrix lamarckii |
CULTURE PRACTICES
Hard clams are cultured in areas where the bottom is composed of fine sand or a mixture of sand and mud. In order to avoid losses from undesirable weather, such as storms, culture sites are selected in sheltered areas. Chinese fishermen usually purchase the young clams (5–10 mm in shell length) from spat collectors in spring and transplant them immediately in the carefully prepared culture grounds. Although the clams are sessile organisms they tend to move considerably from the site where they are originally sown. For this reason, it is common practice to erect a net wall 20–30 cm in height around the culture site, in order to prevent the clams from escaping or being washed away. Although this measure successfully retains the clams in the area, fishermen must regularly inspect the net to thin the hard clams which have piled around the base of the net itself. The hard clams reach the marketable size of 5–8 cm in 2–2.5 years and production per square meter ranges between 2–4 kg. Total culture output in 1987 was 53,389 MT. One major constraint to the further expansion of this seafarming activity is the limited and often unreliable seed supply.
PRODUCTION
HISTORY
Three species of hard clam belonging to the genus Meretrix are cultured in China. The main culture grounds are in Jiangsu, Shandong and Liaoning provinces. The annual production of hard clams in recent years has been gradually increasing, however potential culture sites are becoming less available as they have been utilized for culturing other marine species particularly shrimp. Hard clam seeds are collected entirely from the wild and no hatchery exists in China. The supply of natural spat from year to year is unstable due to changing environmental conditions.
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  |
| M. meretrix & M. lusoria | ||
| Source of seed | Wild | |
| Culture method | Bottom | |
| Yield/ha | NA | |
| Market | Domestic | |
| Production area | NA | |
| Status of culture | Developing | |
| Major constraints | Limited seed supply | KEY MAP |
 | Ruditapes philippinarum |
CULTURE PRACTICES
The bottom method is the basic practice for culturing clam in China. Culture sites are selected in intertidal areas with mud-sand bottoms. The culture site must be sheltered from high waves and strong wind. In spring, the fishermen spread the spat which range between 1–1.5 cm in length over the selected culture site during low tide. The culture density varies according to the environmental parameters prevailing at any given site, however culture density is usually in the range of 250–500 spat/sq. m. After a culture period of about 8–9 months the clams will have attained a shell length of 3–4 cm and are ready to be harvested. Market size clams are mostly consumed locally, however an export market is also emerging. Polyculture of Manila clam with marine shrimp (Penaeus orientalis) in brackishwater ponds has been carried out on an experimental basis. In 1988, the total national production from culture was 33,986 MT from a culture area of 66,000 hectares. Major constraints affecting the industry are the limited seed supply and pollution of coastal waters.
PRODUCTION
HISTORY
Ruditapes philippinarum or Manila clam is the main clam species cultured throughout the coast of China. In the southern provinces of China a semi-artificial spat rearing method has been developed for obtaining spat. Sexually mature specimens are placed by fishermen near the sluice of earthen pond. The water flowing from the ponds over the clams tend to be warmer and thus inducing spawning. Spat of 1 cm in length are then transported to the culture site located in intertidal areas. In northern China the seeds are collected from wild.
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  |
| Ruditapes philippinarum | ||
| Source of seed | Wild and artificial | |
| Culture method | Bottom | |
| Yield/ha | 0.5 MT/ha | |
| Market | Domestic and export | |
| Production area | 66,000 ha | |
| Status of culture | Developing | |
| Major constraints | Limited seed supply Environmental pollution | KEY MAP |
 | Sinonovacula constricta |
CULTURE PRACTICES
Razor clam usually inhabit intertidal areas with flat, muddy or sand-muddy bottoms. Good water current is an important condition required for its culture. The spawning season of the razor clams is closely related to water temperature and therefore specimens from different localities tend to spawn at different times. In Fujian spawning season occurs between mid-October and mid-November, while in Liaoning province spawning starts at the end of June. Before seeding takes place, Chinese fishermen prepare the culture grounds to minimize spat losses. The size and shape of the culture grounds are determined by a number of environmental conditions prevailing on the site. The common practice is to make ditches between beds along the same direction of the tide current as well as constructing dikes on the side of open sea in order to minimize wave action. Razor clams reared for one year usually attain a shell length of 4–5 cm, while two-year old specimens measure about 6 cm. After two years culture the growth rate decreases sharply and high mortality occurs. One major constraint affecting further expansion of this activity is the limited supply of seed.
PRODUCTION
HISTORY
Razor clam seafarming started about 500 years ago mainly in the southeast of China particularly in the Fujian and Zhejiang coastal regions. In recent years, the fishermen from Shandong Province have shown great interest in razor clam and culture sites have been established. Expansion is however limited by the fact that the spat have to be bought from Zhejiang Province. In the early 1950's scientists made considerable progress with regard to seed collection methods by improving spat settlement techniques. At present there are 21,000 ha being cultured which produced 140,673 MT in 1988.
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  |
| Sinonovacula constricta | ||
| Source of seed | Wild | |
| Culture method | Bottom (intertidal zone) | |
| Yield/ha | 6.7 MT/ha | |
| Market | Domestic | |
| Production area | 21,000 ha | |
| Status of culture | Developing | |
| Major constraints | Limited seed supply | KEY MAP |
 | Chlamys farreri Chlamys nobilis Pactinopecten yessoensis Argopecten irradians |
CULTURE PRACTICES
There are two methods of scallop culture practiced in China: bottom and raft culture. For both methods culture site should be selected in areas where seawater is clear and current is swift. With regard to bottom culture, the method is rather simple but effective and economical. Fishermen release the scallop spat from a moving boat on the pre-selected area. The spats are left there until they attain the marketable size. This method is mainly restricted by water depth, shore profile, bottom currents and seabed composition. The raft and long-line culture are used in deep water areas. One long-line unit is usually 60 m in length. Buoyancy and anchoring arrangements depend on the local conditions, loading, kind of hanging structure used, and degree of fouling. Usually 40–60 netcages are suspended from one long-line. Several types of container for culturing scallops are being used, however pearl and lantern nets are popularly used. Lantern nets are usually 1 m in height and 40 cm in diameter and divided in 6–7 chambers. Each chamber has a lateral opening through which the scallops are introduced. The stocking density per compartment is 30–35 scallop.
PRODUCTION
HISTORY
Scallop seafarming started almost 10 years ago following the success in artificial rearing of spat in controlled conditions. At present, there are about 3,500 hectares of culture area and, in 1988 the production was 121,991 MT, a considerable increase over the previous years. There are two species mainly cultured in China: Chlamys farreri and the bay scallop Argopecten irradians. Scallops are mainly cultivated in the northern provinces of China, particularly in Liaoning and Shandong. On the contrary, scallop culture in the southern provinces has not yet developed, possibly due to unfavorable environmental conditions.
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  | |
| C. farreri & A. irradians | |||
| Source of seed | Artificial | ||
| Culture method | Raft | ||
| Yield/ha | 35 MT/ha | ||
| Market | Domestic & export | Domestic | |
| Production area | 2,000 ha | 1,500 ha | |
| Status of culture | Developed | Developing | |
| Major constraints | Limited suitable areas | KEY MAP | |
 | Haliotis discus hannai Haliotis diversicolor Haliotis fulgens Haliotis rufescens |
CULTURE PRACTICES
Prior to induce spawning the abalones are conditioned by controlling the temperature level of seawater. Spawning is induced with a variety of methods such as desiccation, thermal shock and UV irradiated seawater. Matured individuals are usually exposed to air for 1 hr and then placed into tanks with flowing UV-irradiated seawater. Spawning usually occurs within 3–4 hrs. Abalone culture methods include pond, bottom and raft culture. Where bottom culture is practiced, sites with suitable environmental conditions are selected. Young abalones are released into these areas when they reach 2 cm in length. There are two types of pond for abalone culture: intertidal ponds and land based pond covered by green houses. In the latter type the abalones can be cultured throughout the year. Raft culture is widely adopted by Chinese fishermen. The rafts are located in protected areas and the abalones are placed in bamboo, wood, plastic or net containers which are then hung from the floating raft. Abalone are also polycultured with seaweed such as Laminaria and Undaria. Although China is a major abalone producing country, production data is scanty.
PRODUCTION
HISTORY
Abalone culture in China started almost 10 years ago in Liaoning and Shandong provinces following the successful rearing of juveniles under controlled condition in the 1970's. Haliotis discus hannai and Haliotis diversicolor are the major species farmed in the north and south of China, respectively. The above seafarming activity is expanding slowly due to a number of reasons: 1) abalone require a much longer growing period (3–4 years) than other cultured species; 2) high initial capital investment; and 3) high mortality rate occurring during the first year. Considerable research efforts are being carried out to solve such constraints.
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  | |
| H. discus & H. diversicolor | |||
| Source of seed | Artifical | ||
| Culture method | Raft & pond | Raft & bottom | |
| Yield/ha | NA | ||
| Market | Domestic | ||
| Production area | NA | ||
| Status of culture | Developing | ||
| Major constraints | Long culture period | High initial investment | KEY MAP |
 | Laminaria japonica |
CULTURE PRACTICES
The basic culture unit for Laminaria cultivation consists of a long-line buoyed with numerous floats and anchored at both ends. The line is usually strong and made of durable, non-corrosive synthetic fibre, such as nylon, about 2.0–2.5 cm in diameter. A floating line is typically 45–55 m long. In less exposed areas the line may be 55–65 or even 70 m in length, whereas in very exposed regions, length may be shortened to 30–45 m. Laminaria seedling plants are attached to ropes (known as culture ropes) for the grow-out phase. The culture ropes are usually between 1.5–3.0 m in length and are suspended from the long-line 50–100 cm apart. Glass floats 25–30 cm in diameter are used to buoy the long-lines however large plastic floats are often used as alternative. There are various kind of long-line systems, however the most commonly used are the single and multi-line. The single line is an independently positioned unit, i.e. it is not joined to other lines. A multiline unit is usually composed of 10–40 floating lines joined in a parallel fashion. The parallel lines are positioned 3–5 m apart to allow adequate water circulation and avoid tangling of the mature kelp plants.
PRODUCTION
HISTORY
Scientists begun researching on the artificial propagation of Laminaria in the early 1950's. Having solved a number of biological and technical constraints, such as seedling rearing, Laminaria seafarming became the largest mariculture industry in China. To date there are over 7,200 hectares of kelp culture which extend from Liaoning to Fujian province. The annual dry weight production of kelp in China is the largest for any single marine species cultivated worldwide. Output peaked in 1980 with a dry weight production of 252,907 MT. Production in 1988 was 216,415 MT.
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  |
| Laminaria japonica | ||
| Source of seed | Artificial | |
| Culture method | Raft | |
| Yield/ha | 30 MT/ha | |
| Market | Domestic | |
| Production area | 7,200 ha | |
| Status of culture | Developed | |
| Major constraints | NA | KEY MAP |
 | Porphyra yezoensis Porphyra haitanensis |
CULTURE PRACTICES
There are three methods used for culturing laver: rack, semi-floating raft and raft. The floating raft is the culture method most popularly adopted by fishermen in southern China (Zhejiang, Fujian and Guangdong provinces). This method has two major components: a raft net and stakes. Culture units are anchored in the intertidal zones where the water current speed averages 12 m/min. During high tide the raft nets float on the water surface while they become exposed to air during low tide. By doing so, daily management and maintenance is facilitated, particularly as this system prevents diatoms and other fouling organism from settling on the raft. The stakes fitted at the edges of the raft net prevent it from sinking to the seabed during low tide. Rack and raft culture methods are practiced in deep water regions, mainly in northern China (Liaoning and Shandong provinces). Harvesting of P. haitanensis starts towards mid-October, in early December for P. yezoensis. The former yields on average 3,500 kg/ha, the latter 1,500 kg/ha. Major constraint to the industry is the limited availability of suitable culture grounds.
PRODUCTION
HISTORY
Laver has been cultured for over 300 years in China. Fishermen used to remove fouling organisms from intertidal rocks in August and limewash them to create a clear surface for laver conchspore to settle at the end of September. After 40 days growing, (i.e. early November) the fully grown laver were harvested. Artificial culture of Porphyra yezoensis and Porphyra haitanensis begun in 1959 and 1966, respectively. The former is the most important species cultured in China. In 1988 the output was 15,576 MT from a culture area of about 6,400 hectares.
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  | |
| P. yezoensis & P. haitanensis | |||
| Source of seed | Artificial | ||
| Culture method | Raft and rack | ||
| Yield/ha | 2 MT/ha | 3 MT/ha | |
| Market | Domestic | ||
| Production area | 400 ha | 6,000 ha | |
| Status of culture | Developed | ||
| Major constraints | Limited suitable areas | KEY MAP | |
 | Stichopus japonicus Thelenota ananas |
CULTURE PRACTICES
Due to a number of biological and ecological characteristics peculiar to sea cucumber, it is rather difficult to culture it using any of the culture methods adopted for other maricultured species. Sea-ranching is the commonly adopted method by fishermen for sea cucumber culture. When an area is selected as the culture ground, sea cucumber predators are removed and numerous rocks are introduced in order to create shelters for the cultured organisms. Juvenile sea cucumbers measuring > 1 cm are released in the above areas at a density of 5–10 specimens/sq. m. where they will remain until they have reached the commercial size. S. japonicus attains the marketable size of 250 g fresh weight (15–16 cm in body length) in 2–2.5 years. Sea cucumber cage culture (S. japonicus) is experimentally being carried out. After harvesting the holothurians are cleaned, degutted and boiled and dried until they retain only 8–10% of the body moisture. Major constraint to the industry is the low production possibly due to the limited availability of juveniles and of suitable culture grounds. Existing culture grounds are mainly located around Liaodong and Shandong peninsulas.
PRODUCTION
HISTORY
Two species of sea cucumbers are cultured in China: Stichopus japonicus and Thelenota ananas. Sea cucumbers are regarded as one of the most precious edible marine organisms due to their high nutrient and medical values. Chinese scientists began applying on sea cucumber culture techniques almost 40 years ago and succeeded to artificially rear seedlings in the early 1980's. At present, a number of hatcheries operate in China, however they do not produce enough juveniles to meet culture demand. The total culture production has increased from 50 MT (dry weight) of the 70's to over 100 MT in 1987.
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  | |
| S. japonicus & T. ananas | |||
| Source of seed | Artificial | ||
| Culture method | Searanching & cage | Searanching | |
| Yield/ha | NA | ||
| Market | Domestic | ||
| Production area | NA | ||
| Status of culture | Developing | ||
| Major constraints | Low production | KEY MAP | |
 | Hippocampus trimachtatus Hippocampus japonicus |
CULTURE PRACTICES
Sea horses are cultured in indoor or outdoor concrete tanks. Tanks vary in size depending on a number of environmental parameters as well as management convenience. In natural conditions spawning season is closely related to seawater temperature. In localities where temperature does not fall below 20 °C spawning may occur throughout the year. In Guangdong province the spawning period extends from March to November with a peak period from July to August. The fecundity of this organism is relatively high: one adult H. trimachtatus can give birth to as many as 1,000 offsprings per spawning. At favorable environmental conditions spawning can occur four times a year. Sea horse broodstock are fed with live organisms such as Calamus sp. and Acartia sp., while larvae are fed on organisms such as Balanus sp., Penaeus sp. and Acetes. Feeding rate varies depending on the body length of the cultured organism. Sea horses with a body length of 1 cm are fed daily 20% their body weight, while specimens of 11 cm are fed 10% their body weight. The major constraint to the further expansion of sea horse culture in China is the limited market demand.
PRODUCTION
HISTORY
Two species of sea horse are commercially important in China: Hippocampus trimachtatus and Hippocampus japonicus. Culture of the above species has been practiced since the early 1970's, mainly in southeast coastal regions of the country: Guangdong, Zhejiang and Jiangsu provinces. Dried sea horse is mainly used as a traditional medicinal product and therefore market demand is rather limited. As a result this marine organisms are cultured only on a small scale in most the coastal provinces of China. Annual production has been estimated to be in the range of 1 MT.
TOTAL REGIONAL PRODUCTION
STATUS OF CULTURE
| TOPIC | SPECIES |  |
| H. trimachtatus & H. japonicus | ||
| Source of seed | Wild and artificial | |
| Culture method | Tank | |
| Yield/ha | NA | |
| Market | Domestic and export | |
| Production area | NA | |
| Status of culture | Developing | |
| Major constraints | Low market demand | KEY MAP |
