1. MARINE FISHERIES DEVELOPMENT IN CHINA

1.1 Historical Background
1.2 Government Policy and Strategies
1.3 Sea Farming and Sea Ranching Development in China

China is situated in the eastern part of Asia, on the west coast of the Pacific Ocean (see map on p. v). The South China Sea, East China Sea, Yellow Sea and Bohai Sea expand from tropical to subtropical and temperate zones, covering a total area of 1.3 million square nautical miles, of which the continental shelf occupies 431 000 sq.n.mi. China has a curved coastal line 18 000 km long, extending from the Yalujiang River in the north to the Beilun River in the south. There are 6 500 islands, their coastline totalling 14 000 km. Numerous rivers (mainly the Yazhi River, Pearl River, Yellow River and Hailongjiang River) bring on average 1 600 milliard cubic metres of fresh water into the sea. This water carries abundant nutrients which contribute to the enrichment of the fishing grounds and the creation of prime conditions for sea farming and sea ranching. Such favourable conditions provide China with more than ten million metric tons of marine aquatic products annually.

According to data obtained from national oceanic surveys, there are 20 278 different species living in China's marine environment, including 4 200 species in the Yellow Sea and the Bohai Sea, 11 300 species in the East China Sea and 12 900 species in the South China Sea. There are hundreds of species of seaweed, fish, crustaceans, molluscs, echinoderms, etc. with a commercial value.

In China, over nearly half a century, the exploitation and utilization of these vast fishery resources went through various phases, progressing from under- to overexploitation and finally to rational exploitation. This last objective ensured that fishery industry development became rational and sustainable, through sound sea farming and sea ranching practices.

1.1 Historical Background

1.1.1 Period 1950-1959: initial development
1.1.2 Period 1960-1976: stagnating development
1.1.3 Period 1977-1999: rapid development
1.1.4 Actual status of sea farming and ranching

In 1949, China's fisheries yielded merely 448 000 metric tons (mt). Fifty years later, total fisheries production amounted to 41.224 million mt, of which 14.976 million mt from marine capture fisheries and 9.743 million mt from sea farming/ranching (Table 1). Rational fishery policies and the collaborative efforts of fishermen and scientists working in these fields were at the basis of such success.

Marine fisheries development began in the early 1950s, progressing through three successive development phases:

- 1950-1959 Initial development
- 1960-1976 Stagnating development
- 1977-1999 Rapid development

1.1.1 Period 1950-1959: initial development

In 1950, very few of the existing 78 000 fishing boats were equipped with diesel engines and marine capture fisheries produced 546 000 mt only (Table 3). Then, the number of powered fishing vessels increased rapidly. By the end of the 1950s, their number reached 2 443, totalling 187 000 HP; there were still 127 000 non-powered fishing boats with a total tonnage of 642 000 t.

As a result, total production of marine capture fisheries increased to 1.754 million mt (Table 3). It was evident that the greater the number of powerboats, the greater the catch. There was also a stable increase in production per unit of power and marine species with a high commercial value were well represented. From these observations, it could be concluded that the fishery was underexploited.

During this period, sea farming/ranching production was still a small fraction of both marine capture fisheries and total productions (Table 3), due to lack of equipment and absence of the indispensable knowledge and technology.

Table 3. Fisheries productions in China, 1950-1959[3]

Year	Total production (P,’000 mt)	Marine fisheries		C/P (percent)	C/F (percent)
		Capt. Fisheries (F, ‘000 mt)	Farming/ranching (C, ‘000 mt)
1950	911	546	10	1.09	1.83
1951	1332	814	30	2.25	3.68
1952	1666	1060	60	3.60	5.66
1953	1899	1218	70	3.68	5.74
1954	2293	1305	87	3.79	6.66
1955	2517	1549	106	4.21	6.84
1956	2647	1642	64	2.41	3.89
1957	3116	1814	122	3.91	6.72
1958	2811	1623	84	2.98	5.17
1959	3087	1754	105	3.36	5.98

1.1.2 Period 1960-1976: stagnating development

During this period, China experienced two disasters: the “great leap forward” and the “cultural revolution”. Such political turmoils badly damaged the entire economy, including fisheries. But problems associated with overfishing were not yet present.

By 1976, there were 22 000 fishing powerboats, which was 8.9 times as many as in 1959. Total power of this fishing fleet reached 1.52 million HP, 8.1 times as much as in 1959. There were still 143 000 non-powered fishing vessels totalling 554 000 tons. Landings amounted to 3.122 million mt (Table 4), but yield per unit of power averaged 1.1 tons only or 35 percent less than at the beginning of the period.

Table 4. Fisheries productions in China, 1960 -1976[4]

Year	Total production (P,‘000 mt)	Marine fisheries		C/P (percent)	C/F (percent)
		Capt. Fisheries (F, ‘000 mt)	Farming/ranching (C, ‘000 mt)
1960	3038	1749	121	3.9	6.9
1961	2305	1336	91	3.9	6.8
1962	2283	1410	88	3.9	6.2
1963	2614	1671	91	3.5	5.4
1964	2804	1804	76	2.7	4.2
1965	2984	1910	104	3.5	5.4
1966	3098	2056	120	3.9	5.8
1967	3052	2053	140	4.6	6.8
1968	2711	1776	144	5.3	8.1
1969	2899	1891	156	5.4	8.2
1970	3185	2097	184	5.8	8.8
1971	3496	2331	229	6.5	9.8
1972	3842	2659	256	6.7	9.6
1973	3931	2691	221	5.6	8.3
1974	4248	3006	248	5.8	8.3
1975	4412	3068	279	6.3	9.1
1976	4476	3122	297	6.6	9.5

During this phase, there was still a stable production increase (Table 4) as the number of fishing boats increased, but production per unit of power and percentage of high quality fish decreased. Although Farming/ranching developed, the growth was slow for similar reasons as previously mentioned. In addition, the exceptional historical events had a great impact. They interrupted Chinese economic development and the advance of sciences and technology.

1.1.3 Period 1977-1999: rapid development

From 1977, the number of fishing powerboats increased rapidly. By 1998, it reached 473 000, total power exceeding 1.775 million HP. Among them, there were 283 000 marine fishing vessels, ten times more than in 1974. Number of non-powered boats decreased to 27 240, totalling 39 372 tons. In 1999, landings from marine capture fisheries went up to 14.976 million mt (Table 5), a slightly higher figure than in 1998.

In 1997, Chinese fishery authorities predicted that the increase of capture fisheries yield would reach zero in future years based on this year figures and they encouraged further development of the aquaculture industry. Sea farming/ranching developed rapidly since the late 1970s and particularly in the 1980s, following new government policy, numerous reforms and free access to foreign technology (Table 5). These changes strongly encouraged and supported the development of the fishery industry as a whole and, in particular, aquaculture including sea farming and sea ranching.

Table 5. Fisheries productions in China, 1977-1999[5]

Year	Total production (P,‘000 mt)	Marine fisheries		C/P (percent)	C/F (percent)
		Capt. Fisheries (F, ‘000 mt)	Farming/ranching (C, ‘000 mt)
1977	4695	3195	424	9.0	13.3
1978	4653	3145	449	9.6	14.3
1979	4305	2772	416	9.7	15.0
1980	4497	2813	444	9.9	15.8
1981	4606	2774	458	9.9	16.5
1982	5155	3098	495	9.6	16.0
1983	5458	3072	545	10.0	17.7
1984	6193	3305	639	10.3	19.3
1985	7052	3485	712	10.1	20.4
1986	8236	3896	858	10.4	22.0
1987	9552	4381	1101	11.5	25.1
1988	10609	4608	1425	13.4	30.9
1989	11517	5036	1576	13.7	31.3
1990	12371	5509	1624	13.1	29.5
1991	13539	6096	1905	14.1	31.3
1992	15576	6912	2425	15.6	35.1
1993	18262	7673	3087	16.9	40.2
1994	21464	8959	3456	16.1	39.6
1995	25712	10268	4123	16.0	40.2
1996	28131	11263	4376	15.6	39.9
1996[6]	32879	12489	7639	23.2	61.2
1997	36018	13854	7910	22.0	57.1
1998	39067	14967	8600	22.0	57.5
1999	41224	14976	9743	23.6	65.1

Although the number of fishing boats continued to increase, total production kept increasing also. Unfortunately, production per unit of power decreased seriously, resulting in the use of four to five tons of fuel to capture one ton of fish. Captures increasingly consisted of trash fish and of steadily younger individuals, the average size of the fish caught getting smaller and smaller. It became apparent that maximum sustainable yield had been reached and that overfishing was taking place.

Due to overfishing, the composition of marine catches changed substantially and traditional marine species with a high value sharply declined. Of the four species with the greatest commercial value, i.e. the large yellow croaker (Pseudosciaena crocea), the small yellow croaker (P. polyactis), the hairtail (Trichiurus haumela) and the squids (Sepiidae), only the hairtail was still well represented, although young individuals were present in large numbers in the catches. Conversely, total production of pelagic fish and crustaceans increased (Table 6). In both the East China Sea and the Yellow Sea, demersal and predatory pelagic species with a longer life span and a higher commercial value were replaced by low value species, primarily small pelagic fish such as the chub mackerel (Pneumatophorus japonicus), the black scraper (Navodon modestus) and the Japanese anchovy (Engraulis japonicus).

Table 6. Composition of marine catches in China, 1978-1996
(in thousand metric tons)

Year	P. crocea	P. polyactis	Hairtail	Chub mackerel	Scads	Black scraper	Anchovy	Crustaceans	Molluscs	Seaweed	Jellyfish
1978	93.8	23.9	387.2	112.9	169.4	310.4		505.9	330.3	259.8	3.6
1979	82.3	35.7	437.2	111.6	91.4	105.4		408.3	307.7	250.4	13.0
1980	86.4	36.0	413.3	83.8	160.6	161.4		420.5	313.3	261.6	9.0
1981	79.8	35.2	499.0	73.5	138.3	208.6		418.0	297.3	227.7	18.0
1982	58.6	30.6	493.4	107.0	177.0	265.9		469.4	366.8	228.4	17.6
1983	33.6	28.5	451.8	153.9	212.5	137.9		490.9	420.8	244.9	10.8
1984	40.7	19.6	450.0	123.9	200.0	324.2		593.8	466.9	266.6	36.5
1985	26.1	30.6	458.7	92.6	233.9	272.8		706.4	526.1	273.0	60.9
1986	17.2	19.8	406.4	132.2	238.1	426.9		754.9	719.5	235.4	19.4
1987	17.2	20.1	393.6	166.0	344.8	407.2		870.7	949.0	207.0	58.5
1988	18.1	24.0	365.7	240.7	251.2	263.3		1033.4	1217.7	251.1	32.1
1989	19.4	16.8	416.2	231.6	320.3	393.1	40.0	1057.2	1375.3	300.0	34.9
1990	25.4	23.5	497.7	196.8	387.9	337.2	54.1	1070.5	1473.3	275.2	39.2
1991	25.4	47.2	559.4	242.6	419.9	285.6	113.1	1193.6	1585.8	404.5	96.0
1992	36.4	63.1	622.2	243.1	392.0	158.0	192.7	1274.3	2043.6	568.2	228.5
1993	34.8	78.3	635.3	272.6	260.8	95.5	557.2	1287.2	697.4	12.4	132.6
1994	69.2	103.0	878.1	336.1	430.9	196.3	439.0	1617.2	713.3	15.1	113.4
1995	67.0	153.1	1039.7	372.0	515.3	122.4	489.1	1732.1	828.0	10.6	171.9
1996	80.1	253.5	1071.9	374.4	607.7	210.2	671.4	1917.4	852.9	15.2	265.3

1.1.4 Actual status of sea farming and ranching

To-day, total annual production of sea farming/ranching is close to 10 million metric tons (1999 in Table 7) or 65 percent of the annual yield obtained from marine capture fisheries (Table 5).

Major contributions (1999 in Table 7) are made by molluscs (ab. 8 million mt or 81.5 percent) and seaweed (ab. 1.2 million mt wet weight or 12 percent). Fish and crustaceans contribute only 3.5 and 2.7 percent respectively.

A list of 67 aquatic marine species produced in China through sea farming and sea ranching is given in Table 8. Major farmed species and introduced exotic species are identified.

Table 7. Sea farming/ranching production of major species groups, 1996 -1999
(in thousand metric tons)

Year	Total	Seaweed	Fish	Crustaceans	Molluscs	Others
1996	7639	914	182	129	6407	7
1997	7911	961	255	162	6511	22
1998	8600	1024	307	214	7003	52
1999	9743	1173	339	266	7935	30

Table 8. Aquatic marine species farmed and ranched in China

	Chinese name	English common name (in bold, major species)	Latin name	Note
ECHINODERMS
1		Sea cucumber	Stichopus japonicus	Native
2		Japanese sea urchin	Strongylocentrotus intermedius	Introduced from Japan to Dalian in 1989
MOLLUSCS
Gastropods
3		Abalone	Haliotis discus hannai	Native
4		Abalone	Haliotis discus discus	Introduced from Japan
5		Small abalone	H. diversicolor	Native
6		Red abalone	H. rufescens	Introduced from USA
7		Green abalone	H. fulgens	Introduced from USA
8		Mud snail	Bullacta exarata	Native
9		Top shell	Rapana venosa	Native
Bivalves
10		Pacific oyster	Crassostrea gigas	Native & introduced from Japan
11		Oyster, suminoe	Crassostrea rivularis	Native
12		Dalian Oyster	C. talienwhanensis	Native
13		Oyster	C. plicatula	Native
14		Northern scallop	Chlamys farreri	Native
15		Southern scallop	Chlamys nobilis	Native
16		Gulf scallop	Argopecten irradians	Introduced from USA, 1982
17		Japanese scallop	Patinopecten yessoensis	Introduced from Japan, 1984
18		Pearl oyster	Pinctada fucata	Native
19		Large Pearl oyster	Pinctada maxima	Native
20		Pearl oyster	P. martensii	Native
21		Pigeon pearl oyster	Pteria penguin	Native
22			Coelomactra / Mactra antiquata	Native
23		Hard shell clam	Meretrix meretrix	Native
24		Hard shell clam	Meretrix lusoria	Native
25		Blood cockle	Cyclina sinensis	Native
26		Philippine clam	Ruditapes philippinarum	Native
27		Edible blue mussel	Mytilus edulis	Native
28		Green-lip mussel	Perna viridis	Native
29		Razor clam	Sinonvacula constricta	Native
30		Giant cockle	Scapharca broughtonii	Native
31		Cockle	S.subcrenata	Native
32		Blood cockle	Tegillarca granosa	Native
CRUSTACEANS
33		Chinese shrimp	Penaeus chinensis	Native
34		Japanese shrimp	P. japonicus	Native
35		Banana shrimp	P. merguiensis	Native
36		Black tiger shrimp	P. monodon	Native & introduced from Singapore, Malaysia
37		White shrimp	Litopenaeus vannamei	Introduced from USA
38			P. penicillatus	Native
39		Mantis	Oratosquilla oratoria	Native
40		Mud crab	Scylla serrata	Native
41		Pelagic crab	Portunus trituberculatus	Native
FISH
42		Striped mullet	Mugil cephalus	Native
43		Red-eye mullet	Liza so-iuy	Native
44		Japanese sea perch	Lateolabrax japonicus	Native
45		Black kingfish, Crab eater, Sergeant fish, Cobia	Rachycetron canadum	Native
46		Sea bass, Barramundi	Lates calcarifer	Native & introduced from Thailand
47		Red spotted grouper	Epinephelus akaara	Native
48		Banded grouper	E. awoara	Native
49		Barramundi cod, Hump-backed rock-cod	Cromileptes altivelis	Native & introduced from Malaysia
50		Large yellow croaker	Pseudosciaena crocea	Native
51		Red drum	Sciaenops ocellatus	Introduced from USA,
52		Red sea bream	Pagrosomus major	Native
53		Black sea bream	Sparus macrocephalus	Native
54		Fat greenling	Hexagrammos otaki	Native
55		Black fish	Sebastes nigricans	Native
56		Left-eyed flounder	Paralichthys olivaceus	Native
57		European turbot	Scophthalmus maximus	Introduced from UK, 1992
58		Yellow dab	Limanda yokohamae	Native
59		Redfin puffer	Fugu rubripes	Native & introduced from Japan
ALGAE
Red seaweed
60		Laver or zicai, nori	Porphyra yezoensis	Native
61		Laver or zicai, nori	Porphyra haitanensis	Native
62		Gracilaria	Gracilaria spp.	Native
63			Gelidium spp.	Native
Brown seaweed
64		Kombu or Haidai	Laminaria japonica	Native
65		Wakame or Qundai	Undaria pinnatifida	Native
66		Hizikia	Hizikia fusiforme	Native
67		Giant kelp	Macrocystis pyrifera	Introduced from Mexico & USA in 1978, 1984

* Exotic species introduced from other countries
Main species for sea farming and for sea ranching.

1.2 Government Policy and Strategies

1.2.1 Fishery development support
1.2.2 Fishery resources protection
1.2.3 Fishery access control
1.2.4 Fishing effort control
1.2.5 Establishment of a protection fee

As mentioned above, China’s marine fisheries developed from 1951 to 1999 through three successive phases. During each phase, government policy and strategies were adapted to the concrete situation. In general, they addressed five subject areas, mostly through legislation:

- Fishery development support
- Fishery resources protection
- Fishery access control
- Fishing effort control
- Establishment of a protection fee.

1.2.1 Fishery development support

In the 1950s, China faced economic recovery and development. It was then essential to encourage fishermen to continue to exploit not only existing fishery resources but also to exploit new ones. Table 3 clearly reflects the necessity for and the significance of this new government approach.

Since the late 1970s, it was the decline of the fishery resources which drew serious attention. Government policy and strategies then rather focused on strengthening research aiming at the protection of fishery resources and at their rational utilization, as well as on encouraging sea farming and sea ranching development.

1.2.2 Fishery resources protection

In 1978, the former National Bureau of Aquatic Products decided to amend the “Aquatic Resources Reproduction-Protection Regulations” dating from 1964. The new legislation was authorized by the State Council and came into effect in February 1979.

This was the first specific law concerning fishery protection and utilization. No sooner was the “Details of Aquatic Resources Reproduction-Protection” published that it was applied by 21 provinces, municipalities and autonomous regions successively. It regulated the rational utilization of fishery resources, including catch standards, closed seasons, closed fishing areas and legal fishing gears, as well as sanctions for breaking the law.

On the basis of this law, the protection zone for shrimp in the Bohai Sea and the protection zone for the hairtail and the large yellow croaker in the Yellow Sea and the East China Sea were established to protect the fry/ fingerlings of these economically important fish and the shrimp larvae/juveniles. Agreements with Japan regulated the fishery resources protection zone in the East China Sea and in the Yellow Sea; they also concerned other fishing zones where it was prohibited to use 600 HP fishing boats. In addition, the Xisha and the Zhongsha aquatic resources zones were established in the South China Sea. Other protection measures were also taken for the East China Sea, Yellow Sea and South China Sea, such as the summer closure of the trawling fishery and the control of the size of captured juveniles.

Another important historical event was the approval and publication of the “Fishery Law of the People’s Republic of China”. In 1979, the former National Bureau of Aquatic Products organized specialists to draft this new fishery law on the basis of foreign legislative experiences and of some valuable points of view expressed by fishery enterprises. The law was discussed and authorized by the National Congress to come into effect on July 1,1980. In 1987, the State Council ratified the “ Details of the Fishery Law”. These laws were the foundation of the Chinese fishery legal system.

The Fishery Law regulated fishery industry development and administrative aspects of aquaculture, marine capture fisheries, stock enhancement and fishery resources protection. It clearly encouraged aquaculture development, protected the legal rights of producers and supported pelagic fishery development, limiting exploitation of inner seas and inland waters. To support sustainable development, this law changed the existing trends substantially, giving priority to management instead of exploitation, to culture instead of capture and to quality instead of quantity.

1.2.3 Fishery access control

Fishing licences were adopted by many countries where they became an effective management tool, especially since the legislation on the 200-mile exclusive economic zone came into effect. In China, there was no fishing licences until 1979. This seriously interfered with the normal administration of the fisheries. Therefore, in 1979, the National Bureau for Aquatic Products published the “Temporary Regulation on the Issue of Fishery Licences” which established that fishing enterprises should apply for a fishing licence from the fishery administration department. This licence defined the fishing boat operative model, the scope and duration of fishing operations, the species to be captured and the procedures to be followed to use the licence. Since 1980, Chinese fishery authorities controlled fisheries exploitation through fishing licences, the licensing system for boat construction being introduced later.

In order to support sea farming/ranching development, government also introduced a farming licence. But it kept owning right and use right separate to give priority to the user’s right. Farming licences were valid for the producer only and, for example, if he left the farming area without reasons, the farming licence was cancelled.

1.2.4 Fishing effort control

By 1981, a large number of fishing boats had been built because of the adjustment of the production system on a village basis. Fishermen began to look for improper profits, worsening the bad conditions in which marine resources were already. As a result, they lost money, labour power and fuel, as well as economic viability.

In 1983, the Ministry of Agriculture published the “Administrative Directives for Control of Marine Fishing Vessels” to control the increasing number of fishing vessels. Later, in 1987, the State Council transmitted the document entitled “ Opinion on Controlling the Operation of Fishing Boats in Inner Sea Areas”. It was the first document approved by the central government, dealing with the control of fishing operations in inner seas and with the limitation of the size of the fishing fleet.

1.2.5 Establishment of a protection fee

Until 1985, fishermen could exploit fishery resources freely, having no obligation for their protection and management. In order to ensure the sustainable development of the fishery industry, the Ministry of Agriculture and the Ministry of Finance published in 1985 the “Regulation on the Imposition and Management of the Enhancement and Protection Fee for Shrimp Resources of the Yellow Sea and the Bohai Sea”.

Later, the Ministry of Agriculture, the Ministry of Finance and the National Price Bureau prepared and presented to the State Council to be ratified, the “Method for the Imposition of the Fishery Resources Protection Fee”. This regulation had a great influence on the protection and administration of Chinese fishery resources. It also led to the adjustment of the fishery productive framework. Farming and enhancement of aquatic environments became more legalized.

1.3 Sea Farming and Sea Ranching Development in China

1.3.1 Historical review of sea farming and ranching development
1.3.2 Sea farming and sea ranching technology development

The evolution of marine resources exploitation was clearly shown in Tables 5 and 6, production increasing regularly but composition of fishery stocks changing progressively. Fortunately, a good incentive mechanism and an encouraging policy provided support for the development of the sea farming/ranching industry, by combining traditional farming practices with sea ranching practices. The contribution of sea farming and sea ranching productions to total marine fisheries production increased continuously (Table 5), for the benefit of natural fishery resources and fishery products consumers.

1.3.1 Historical review of sea farming and ranching development

About 400 years ago, according to historical records, oyster (Ostrea spp.) spat was collected and cultured by setting bamboo sticks and stone slabs vertically into the lower tidal zone. A few hundred years ago, cultivation of the non-sessile razor clam (Sinonovacula constricta) was mentioned in the Chaozhou city records, eastern Guangdong Province. A few other non-sessile molluscs, such as the ark shell (Tegillarca granosa), the hard clam (Meretrix meretrix) and the clam (Venerupis variegata), were also farmed, some as early as the Ming Dynasty (AD 1368-1644), by scattering natural seed on selected sea beds.

Useful seaweed were farmed in China for ages using the traditional “rock cleansing method”. Farmers knew by experience that in certain parts of the coastal region and during certain seasons, spores of these seaweed would abound. Just before such season, they first cleaned the rocks known to have regularly good growths of the desired seaweed, scraping off barnacles and other sessile organisms, including seaweed. Then, they limed the scraped rocks during low tide. These rocks provided favourable substrates for seaweed spores to settle and develop.

The glue weed (Gloiopeltis furcata) was cultured by this method in the Jinmen County near Xiamen (Amoy), southern Fujian Province, since the Song Dynasty (AD 960-1279). Cultivation of the purple laver or zicai (presumably Porphyra haitanensis) was initiated in the Pingtan County (Haitan Island in southern Fujian Province) at least two hundred years ago, also by this method.

Two other useful seaweed, the Japanese kelp or hadai (Laminaria japonica) and the wakame or qundaicai (Undaria pinnatifida) were introduced into China in the present century, the former in 1927 from Northern Japan and the latter in the late thirties from Southern Korea. In both cases, cultivation consisted simply in throwing stones on the subtidal sea bed during spore shedding seasons, to provide the necessary surface for the spores to settle, to develop and to grow. In all cases of traditional seaweed farming, natural substrates were used for collecting wild spores, mainly stones and rocks.

Another type of traditional sea farming practised for a few hundred years was the “inlet cultivation”: in sheltered coastal regions, small inlets with a narrow mouth were selected; in spring, when shrimp larvae (Penaeus chinensis) and mullet fry (Mugil soyui) were abundant, inlets were fenced off and these juveniles were held in captivity until ready for harvest.

Even if more than ten marine plants and animals were traditionally farmed in China for the last few hundred years, total annual production was small, amounting to less than 10 000 mt because of the low efficiency of the methods used and their dependence on wild seed and natural substrates.

Since the foundation of the People's Republic of China in October 1949, sea farming/ranching underwent great changes. Traditional sea farming/ranching as described above gave way to new technologies involving seed production by artificial means, use of artificial substrates for sessile organisms, and construction of special enclosures to rear pelagic organisms fed with natural and balanced feeds.

During the 1950s, China’s economy was slowly recovering (Section 1.1.1). In 1950, sea farming/ranching production totalled 10 000 mt only. But later, development was rapid: production reached 545 000 mt in 1983, annual growth rate averaging about 16 percent (Tables 3 and 5).

It is interesting to note the sudden great increase in sea farming/ranching production from 84 000 mt in 1958 to 105 000 mt in 1959 (Table 3). This was undoubtedly due to the great increase in kelp (Laminaria japonica) production, from 6 253 mt in 1958 to 23 886 mt in 1959, following the intensification of sea fertilization and the extension of Laminaria farming southwards (Section 1.3.2 a). Since then, the contribution of kelp production to total sea farming/ranching production remained important. From 1967 to 1980 for example, it was responsible for 50 to 60 percent of the total Chinese sea farming/ranching production. This percentage decreased somewhat from 1981-1983, following the increased productions of molluscs and shrimps (Tables 3 and 7).

Before 1950, there were only 11 species or species groups (incl. four seaweed, five molluscs, one shrimp and one fish species) under cultivation by traditional methods. Strictly speaking such methods did not belong to the field of scientific sea farming/ranching. From 1950, because of the great interest of the new government for science and technology, marine biologists were mobilized to find solutions to problems constraining sea farming/ranching development. Scientific breakthroughs were soon made in basic and applied research on seaweed such as Japanese kelp (Laminaria japonica) and purple laver (Porphyra tenera), for example resolving the problem of the origin of the spores involved in cultivation. This led to successful farming of Laminaria in the fifties and of Porphyra in the sixties. Both species became pillars of the sea farming/ranching industry in China: annually, Laminaria production reached 1.5 million mt (250 000 mt dry kelp) and Porphyra production reached 120 000 mt (12 000 tons dry laver).

Research efforts were also directed at the study of the ecology and developmental biology of the Chinese shrimp (Penaeus chinensis). Laboratory experiments on mature shrimp to make them spawn under controlled conditions were successfully carried out in the late fifties to early sixties. This laid the foundation for the development of large-scale production of shrimp larvae and therefore, of shrimp farming, another important pillar of China’s sea farming/ranching industry.

In the fifties, research was also conducted on the biology of economically important molluscs, in particular on the ecology, life history and larval culture of mussels and scallops. These studies laid the foundation for their farming development in the seventies and eighties. Mussel cultivation was an important pillar of the sea farming/ranching industry during the1970s and the 1980s, producing over 114 500 mt in 1983. Development of scallop farming followed up closely.

Two other molluscs, oyster (Ostrea spp.) and razor clam (Sinonovacula constricta), were also cultured traditionally for ages and they still are important pillars of China’s sea farming/ranching industry. In the old days, oyster cultivation was in a more advanced stage of development than the cultivation of other marine organisms, since it was already using artificial substrates, such as bamboo sticks, for collecting oyster spat. Cultivation of razor clam depended on natural spat occurring in certain areas, the collected spat being then distributed on previously levelled and prepared grounds for cultivation.

The above-mentioned species are at present the main marine organisms under cultivation (Table 9). By now, their annual productions are all well above 10 000 mt, with Japanese kelp as the leading species. Production of this dried seaweed was over 200 000 mt, equivalent to more than l.2 million mt fresh weight. These main farmed organisms contribute about 90 percent of the total sea farming/ranching production.

During the last fifty years, sea farming and sea ranching became increasingly more and more important, and the contribution of their productions to total marine fisheries production increased from l.8 to 24 percent (Tables 3 to 5). To-date, the growth rate of sea farming/ranching production is greater than that of the marine capture fisheries. We are gradually becoming the masters of the sea by transforming it into our farm and eventually into our ranch.

Table 9. Relative importance of major sea farming/ranching species
(annual production P and percent contribution to total sea farming/ranching production P/T)[7]

Cultured species	1978		1983
	P (metric tons)	P/T (percent)	P (metric tons)	P/T (percent)
Japanese kelp (Laminaria japonica)	256 200	56	231 296	42
Blue mussel (Mytilus edulis)	96 190	21.4	114 500	21
Razor clam (Sinonovacula constricta)	47 000	10.5	89 000	16.3
Oysters (Ostrea spp.)	31 000[8]	6.2	35 500	6.5
Purple laver (Porphyra spp.)	4 427	1.0	9 987	1.8
Chinese shrimp (Penaeus chinensis)	1 245[9]	0.3	8 975	1.6
Total	433 062	95.4	489 258	89.2

1.3.2 Sea farming and sea ranching technology development

As just mentioned, development of the Chinese sea farming/ranching industry greatly depended on the farming of six marine plants and animals, the production of which accounted for about 90 percent of total sea farming/ranching production. The farming technology applied for rearing two of these organisms, oyster and razor clam, did not improve much since 1950, their production increasing rather slowly but steadily. In contrast, the production of the other four organisms (kelp, laver, mussel and shrimp) started with a very limited production after 1950. But, following a series of technological breakthroughs, their production rapidly increased.

These major advances in Chinese sea farming/ranching technologies are reviewed in the following sections, more detailed information on the biology of the species themselves being presented in Chapter 2.

(a) Japanese kelp farming development

The major increase in the production of Japanese kelp (Laminaria japonica) dates from the 1950s when its annual yield of 40.3 mt (dry) in 1949 increased to 6253.3 mt in 1958, a 155 time increase within a few years (Table 10). This was made possible by the introduction of rafts as artificial substrates for kelp growth.

Before 1952, kelp cultivation entirely relied on natural substrates made by throwing stones on the sea floor or breaking submarine rocks. The first successful experiment was made in 1952 when spores were collected on artificial substrates made of palm ropes assembled in the form of floating rafts producing about 10 mt of dry kelp. This was the first time that kelp was grown and harvested on an artificial substrate built in the form of rafts. The use of this technology is one of the keys of the successful development of the Chinese kelp industry.

When the “floating raft method” was first introduced, most farmers were not convinced of its value, preferring the sea bed cultivation method on natural rocks and stones. Until 1955, production of kelp by this last method was still leading, with 321.8 mt against 206 mt from raft culture (Table 10). But in 1956, raft culture production began to lead, with 391.7 mt dry weight against 167.7 mt from sea bed growth, and in 1958, raft culture produced 5267.3 mt against 986.2 mt by sea bed culture. Since then, sea bed cultivation on natural rocks has been abandoned as a method for the commercial farming of seaweed.

Table 10. Production of Japanese kelp, 1946 -1958[10]

Year	Production on natural substrates (mt dry weight)	Production on artificial substrates, A (mt dry weight)	Total production, T (mt dry weight)	A/T (percent)
1946	24.5
1947	17.3
1948	20.0
1949	40.3
1950	0.7
1951	--
1952	12.0	10.3	22.3	46.4
1953	86.5	28.2	114.7	24.5
1954	251.2	78.7	254.8	30.9
1955	321.8	206.0	527.8	39.0
1956	167.7	391.7	559.3	70.0
1957	580.8	1 439.3	2 020.2	71.3
1958	986.2	5 267.3	6 253.3	84.2

Another reason for the fast development of kelp farming was the successful research on open sea fertilization. It was found that the factor limiting commercial kelp production in certain bays was the low nitrogen content of water. After a series of successful experiments in which porous clay containers were used to apply a nitrogen fertilizer, commercial kelp cultivation could be extended to the so-called outer-sea regions, originally too infertile to support kelp growth. From the early sixties, the kelp industry grew rapidly, individual kelp farms extending on several hectares, even tens of hectares. Because of the fast absorption of nitrogen by kelp and the effectiveness of repeated applications at regular intervals, periodic distributions of a fertilizer solution were recommended. Eventually, mechanical spraying of the fertilizer solution was developed and it became the standard method of application in the Yellow Sea region.

As originally planned, the technology for low temperature culture of summer sporelings was developed to solve the weed problem, the kelp sporelings having a two months' advantage over those produced by the traditional method and thus escaping competition with weeds for space, light and nutrients. But in practice, the method had several additional advantages. Firstly, production was increased by 30 to 50 percent because of the two months' advantage. Secondly, climatic conditions for sporeling transplantation were much milder in late November and early December than those present in January and February when frigid winter conditions prevail. Thirdly, production costs were reduced, more of the cultivation materials being saved.

Another innovation was the southward extension of commercial kelp cultivation into coastal waters of the East China Sea, very rich in nitrogen nutrients. Studies on the effect of water temperature on kelp growth showed that, although optimum growth temperature was 5 to 10 C, temperatures of 13 C or even 15 C still gave an acceptable growth rate. Even at 20 C, some growth was possible. The sporangial sori being still formed at temperatures higher than 10 C, it was concluded that there was a sufficiently long period of low water temperatures in the East China Sea for Japanese kelp to grow to commercial size and to reproduce. Combined with the floating raft farming technology and the low temperature culture of summer sporelings, this gave the possibility to extend kelp cultivation southwards, into the East China Sea region.

All above research successes resulted in increased kelp production (Table 11). Other factors also influenced kelp production. For instance, there was an abrupt increase from 88 294 mt in 1970 to 133 970 mt in 1971, or 152 percent in a single year, following the large-scale use of kelp as raw material for iodine extraction. Later, there was a sudden drop of production from 252 907 mt in 1980 to 219 518 mt in 1981 (13 percent), apparently due to an overproduction in 1980 followed by a market demand more limited than usual.

Table 11. Commercial production of Japanese kelp, 1959 -1984[11]
(in metric tons dry weight)

Year	1959	1960	1961	1962	1963	1964	1965
Production	23 886	49 392	35 784	39 348	29 095	20 551	27 482
Year	1966	1967	1968	1969	1970	1971	1972
Production	43 679	69 815	60 869	76 198	88 294	133 970	158 737
Year	1973	1974	1975	1976	1977	1978	1979
Production	133 739	144 707	159 941	150 426	222 221	251 412	240 137
Year	1980	1981	1982	1983	1984
Production	252 907	219 518	218 258	231 296	250 661

(b) Purple laver farming development

The modernization of purple laver (Porphyra spp.) cultivation was another breakthrough in the development of China’s sea farming. For the last 200 years, the traditional rock cleansing method had helped in supporting Porphyra production to a certain extent. But it was only after solving a series of problems scientifically that Porphyra farming became an established industry.

First of all, a detailed study of the seaweed life history identified the missing link, the spores which developed into leafy plants. It was shown that the conchocelis stage, when mature, formed conchospores (Section 2.1.2c). After liberation, these germinated and produced the leafy Porphyra. Research on the biology of the conchospores permitted to identify the best conditions for the growth of the vegetative stage and for the production of conchospores. This provided the basis for developing the technology for mass culture and intensive collection of spores, by controlling water temperature, photoperiod and light intensity.

Ecological research on the leafy stage, in particular studies on the effects of exposure and water temperature on the growth of intertidal Porphyra species, enabled to develop the modern farming technology. Combining the best aspects of the traditional Japanese pillar method of cultivation with the floating method, resulted in a new technology known as the semi-floating method, especially useful for intertidal cultivation.

Modernization of Porphyra farming was instrumental in the successful development of its industry. Table 12 shows the evolution of the total production of two common Porphyra species, the southern species P. haitanensis and the northern species P. yezoensis. In 1984, total production reached 12 347 mt dry weight, equivalent to about 120 000 mt wet weight.

Table 12. Total production of Porphyra haitanensis and P. yezoensis, 1971-1984
(in metric tons, dry weight)[12]

Year	1971	1972	1973	1974	1975	1976	1977
Production	3 497	3 509	4 074	3 783	4 466	5 395	9 191
Year	1978	1979	1980	1981	1982	1983	1984
Production	8 427	6 630	7 212	7 029	6 815	9 987	12 347

(c) Blue mussel farming development

Blue mussel (Mytilus edulis) farming is well developed in Europe and well known for its enormous productivity. In China, mussel biology was originally studied in the fifties as a fouling organism, which needed to be eradicated. But, in the early seventies, experimental mussel culture was initiated.

Research on blue mussel biology in the Zhifu Bay, northern Shandong Province, showed that larvae occurred from May until early July, the season when kelp was being harvested. It was observed that if floating rafts were left in the water, planktonic mussel larvae would readily attach themselves to the ropes. This method of collecting natural mussel spat is now widely practised in mussel farming.

In areas where natural spat were few or absent, their mass artificial production was necessary. Research on this subject enabled to develop a new technology. Through the use of improved collectors in the rearing tanks, improved larval feeding and inhibition of bacterial growth in the water by antibiotics, over 10 million mussel spat averaging from 350 to 400 µ in length were produced per square metre.

For mussel farming, the floating raft method (Section 3.2) is now widely accepted. Mussels are cultured for six months to one year and harvested in spring or autumn. One long-line raft can produce from 750 to 2 500 kg of fresh mussels per year. In Jiaozhou Bay, annual production averages 1 500 kg per raft. Table 13 shows production of farmed blue mussel in 1970 -1983. It increased from 36 730 mt in 1970 to 114 500 mt in 1983. Average production per hectare also increased, from 36.26 mt in 1978 to 67.62 mt in l983.

Table 13. Production of farmed blue mussel in China, 1970 -1983[13]

Year	1970	1971	1972	1973	1974	1975	1976
Production (metric tons)	36 730	45 870	51 170	44 130	49 700	55 740	59 470
Year	1977	1978	1979	1980	1981	1982	1983
Production (metric tons)	102 075	96 190	65 990	64 000	95 500	-	114 500
Avg. production (mt/ha)		36.26	54.38	50.00	59.94	-	67.62

(d) Chinese shrimp farming development

For farming Chinese shrimp (Penaeus chinensis) successfully, a good knowledge of its biology was necessary. In the early fifties, marine biologists conducted laboratory and field research on its ecology and developmental biology. Results showed that, each year in March, shrimp began to migrate northwards from their winter quarters in the southern Yellow Sea deep waters to their spawning grounds, mainly in the Bohai Sea. There, they scattered into favourable areas for spawning in May, when sea water temperature was about 15°C.

Mature spawners were captured and placed in rearing tanks to produce shrimp larvae under controlled conditions. In order to lengthen the growing period by rearing early-hatched shrimp larvae, early caught females were subjected to induced maturation by unilateral ablation of an eye stalk. In one experiment, female shrimp so treated in early March attained maturation and spawned 20 days later at 17°C. It became thus possible to shorten the spawners’ rearing period and to have two or more breeding cycles each year.

When rearing shrimp larvae under controlled conditions, it was observed that good water quality management and an adequate food supply were essential. Well aerated water, chelation of heavy metals, adequate water temperature and salinity were all important factors. For feeding zoea larvae, the diatom Phaeodactylum tricornutum gave promising results at the optimum density of 100 000 cells/ml. For feeding mysis larvae, newly hatched nauplii of the brine shrimp (Artemia salina) and rotifers (Brachionus plicatilis) gave good results.

The most common system used in China for producing market size shrimp is pond culture (Section 3.1). Ponds are generally constructed by building embankments in the intertidal zone. At high tide, sea water flows in through sluice gates. Occasionally, pumps are used. Individual size of shrimp ponds varies from one or two mu to a few hundred mu[14].

Just as in the case of rearing shrimp larvae, good water quality management and adequate feeding are essential. Dissolved oxygen content, pH, salinity and ammonia content of pond water are of utmost importance. In China, live food was used for many years to feed shrimp, invertebrate animals being crushed before feeding, especially the thin-shelled ones. Cultured mussels were also used as shrimp food. These food resources being limited, formulated feeds were later preferred. As further development of shrimp farming is expected for the next ten years, research on the formulation of artificial feeds are under way at various institutes. According to one study, it seems that best shrimp growth is obtained when using live food and pelleted feeds alternatively.

Before 1950, traditional shrimp culture, trapping larvae and growing them in enclosures without feeding, gave very poor results and production averaged about 75 kg/ha only. Since 1979, the use of modern technology resulted in significant production increases (Table 14). Within five years, shrimp production increased by more than seven times, the area under cultivation doubling only. In 1979, annual production per hectare averaged 169.5 kg, steadily increasing the following years to reach 448.5 kg in 1983. In one special case, average production peaked at 8 265 kg/ha, almost 20 times the 1983 figure.

Table 14. Chinese shrimp production in China, 1979 -1983

Year	1979	1980	1981	1982	1983
Area (ha)	7 333	9 333	13 773	16 553	20 347
Production (mt)	1 295	2 595	3 682	7 079	8 975