Aquaculture In China Research Articles

Development of cryopreservation for maintaining yellow catfish Pelteobagrus fulvidraco sperm

Yellow catfish ( Pelteobagrus fulvidraco) is a candidate freshwater fish for aquaculture in China with its high consumer demand. The aim of this study was to examine the possibility of storage of the sperm of yellow catfish by cryopreservation in liquid nitrogen. Experiments were designed to investigate the effects of the different combinations of three extenders (Ringer extender, Kurokura-1 extender and D-15 extender) and three cryoprotectants (DMSO, Glycerol and Methanol) on the cryopreservation of yellow catfish sperm. Post-thaw sperm motility, fertilization and hatching rate were detected to evaluate the reliability of sperm cryopreservation. The results demonstrated that Ringer extender and 10% methanol was the best combination for protecting the sperm during freezing in liquid nitrogen by a three-step method and thawing in a water bath at 37 °C for 60 s. In this combination for cryopreservation, sperm maintained the highest post-thaw motility (65 ± 5%), fertilization (90.47 ± 3.67%) and hatching rate (88 ± 4%). And more interestingly, the fertilization and hatching rate were similar to those of fresh sperm (97.55 ± 2.74% and 92 ± 5%). Successful sperm cryopreservation techniques for yellow catfish have been developed for hatchery purpose.

Construction of AFLP-based genetic linkage maps for the Chinese shrimp Fenneropaeneus chinensis

Fenneropaeneus chinensis is an important species in marine fishery resources and aquaculture in China. A genetic linkage map is essential for improving the efficiency of its breeding by marker-assisted selection and identifying commercially important genes. Linkage maps of F. chinensis were constructed with an F2 mapping population (110 progenies) using amplified fragment length polymorphic (AFLP) marker in this study. Fifty-five AFLP primer combinations produced 532 AFLP markers fitting for map strategy in mapping family. The markers with 3:1 segregating ratios were analyzed using F2 intercross model for the common linkage map, while the markers with 1:1 ratio were analyzed using the pseudo-testcross strategy. The maps of male, female and common were constructed. The female map included 103 markers that formed 28 linkage groups, covering a total length of 1090 cM. All markers were linked with the linkage groups. Segregation distortion was observed for 6 of 103 markers in the female map. The average distance between markers was 14.53 cM and ranged from 4.4 to 24.8 cM. The male map included 144 markers that formed 35 linkage groups. Ten markers remained unlinked in male map. Segregation distortion was observed for 7 of 144 markers in the male map. The total distance of male map covered 1617 cM. The average distance between markers was 16.36 cM. The male map was 32.6% longer than the female map, which may reflect sex-specific recombination rates in Chinese shrimp. The common map was composed of 216 markers, including in 44 linkage groups covering a total distance of 1772.1 cM. Two markers remained unlinked. No distorted markers of 216 markers were shown in the common map. The distance between markers was 10.42 cM. An average estimated genome size for the Chinese shrimp was 2420 cM, which was consistent with the relative size of the Penaeid genome. The distribution of AFLP markers was relatively even in chromosomes of Chinese shrimp maps. The linkage analysis presented in this work provided some insight into the level of polymorphism and genetic variation of Chinese shrimp.

Environmental impact of aquaculture and countermeasures to aquaculture pollution in China

Aquaculture activities are well known to be the major contributor to the increasing level of organic waste and toxic compound in the aquaculture industry. Along with the development of intensive aquaculture in China, concerns are evoked about the possible effects of ever-increasing aquaculture waste both on productivity inside the aquaculture system and on the ambient aquatic ecosystem. Therefore, it is apparent that appropriate waste treatment processes are needed for sustaining aquaculture development. This review aims at identifying the current status of aquaculture and aquaculture waste production in China. China is the world's largest fishery nation in terms of total seafood production volume, a position it has maintained continuously since 1990. Freshwater aquaculture is a major part of the Chinese fishery industry. Marine aquaculture in China consists of both land-based and offshore aquaculture, with the latter mostly operated in shallow seas, mud flats and protected bays. The environmental impacts of aquaculture are also striking. Case studies on pollution hot spots caused by aquaculture have been introduced. The quality and quantity of waste from aquaculture depends mainly on culture system characteristics and the choice of species, but also on feed quality and management. Wastewater without treatment, if continuously discharged into the aquatic environment, could result in remarkable elevation of the total organic matter contents and cause considerable economy lost. Waste treatments can be mainly classified into three categories: physical, chemical and biological methods. The environmental impacts of different aquaculture species are not the same. New waste treatments are introduced as references for the potential development of the waste treatment system in China. The most appropriate waste treatment system for each site should be selected according to the sites' conditions and financial status as well as by weighing the advantages and disadvantages of each system. Strategies and perspectives for sustainable aquaculture development are proposed, with the emphasis on environmental protection. Negative effects of waste from aquaculture to aquatic environment are increasingly recognized, though they were just a small proportion to land-based pollutants. Properly planned use of aquaculture waste alleviates water pollution problems and not only conserves valuable water resources but also takes advantage of the nutrients contained in effluent. It is highly demanding to develop sustainable aquaculture which keeps stocking density and pollution loadings under environmental capacity. The traditional procedures for aquaculture waste treatment, mainly based on physical and chemical means, should be overcome by more site-specific approaches, taking into account the characteristics and resistibility of the aquatic environment. Further research needs to improve or optimize the current methods of wastewater treatment and reuse. Proposed new treatment technology should evaluate their feasibility at a larger scale for practical application.

ESPR subject area 5 ‘Environmental Microbiology, (Bio)Technologies, Health Issues’

Goal, Scope and Background Aquaculture activities are well known to be the major contributor to the increasing level of organic waste and toxic compounds in the aquaculture industry. Along with the development of intensive aquaculture in China, concerns are evoked about the possible effects of everincreasing aquaculture waste both on productivity inside the aquaculture system and on the ambient aquatic ecosystem. Therefore, it is apparent that appropriate waste treatment processes are needed for sustaining aquaculture development. This review aims at identifying the current status of aquaculture and aquaculture waste production in China.

Genetic diversity analysis of Mystus guttatus from Xijiang Branch of Pearl River

AbstractThe spotted longbarbel catfish (Mystus guttatus) is a member of the family Bagridae and is mainly distributed in the Pearl River Valley and Nandujiang River of Hainan Island. It is one of the four most famous fishes in the history of Pearl River Valley. Nowadays, M. guttatus has become a potential target for aquaculture in China due to its high nutritional value, but its genetic background is still unknown. This study was carried out to estimate its population genetic diversity in Pearl River. The random amplified polymorphic DNA (RAPD) technique was performed on 30 samples, using 20 random primers of length 10 nucleotides. The results showed that each primer amplified 3–9 bands per sample. Twenty primers produced 3210 well-amplified DNA fragments with reproducible band patterns and the average number of amplified DNA fragments reached 107 in each individual. Broadly speaking, 48 (44.9%) of 107 loci were polymorphic. Only the S30 primer did not produce polymorphic loci. The genetic distance of individuals ranged from 0.0467 to 0.2804. The average genetic distance among the 30 individuals was 0.1526±0.037. Genetic data in this study could be useful in genetic resource assessment as well as in wild population conservation and exploitation of M. guttatus in the future.

Observations on shell growth and morphology of the bivalve Ruditapes philippinarum

The bivalve Ruditapes philippinarum is not only one of the main molluse species in the west Pacific Ocean, but also one of the main species for aquaculture in China. Knowledge of growth of the R. philippinarum shell will improve our understanding of the shell as an environmental archive. It is also useful for the aquaculture of R. philippinarum. In this research, a hanging box culture method was introduced in the culture of R. philippinarum. The bivalves were cultured for 126 days, from March 31 to August 3, 2002. The average growth rates of shell width, height, and thickness were 0.069, 0.046, and 0.032 mm/d, respectively. The mean increase of average individual wet mass was 0.028 g/d. The largest growth rates of both shell and average individual wet mass occurred in June, indicating that water temperature and bivalve reproduction were 2 important factors. The shell morphology underwent significant changes with shell growth. The ratio of height to thickness (value of B/C) shifted 1.58 in the first 60 days to 1.54 in the last 30 days, which was resulted from the change in major shell growth direction. Periodic changes in the B/C ratio led to corrugated shell form, which could be used to determine the age of the shell.

Shrimp farming in China: Operating characteristics, environmental impact and perspectives

China has been one of the world's largest shrimp producers since 1988. Although the industry suffered disease outbreaks and environmental problems, shrimp farming has recently seen a rapid expansion in China. This study provides some necessary background to shrimp aquaculture in China. It focuses briefly on the operating characteristics of shrimp aquaculture. Emphasis is placed on the shrimp farming impact on the environment. The promising strategy for reductions in nutrient release from shrimp aquaculture is analyzed. The effective management measures to resolve or mitigate the adverse environmental impact of shrimp farming development have now become necessary and urgent.

Granting quasi-property rights to aquaculturists to achieve sustainable aquaculture in China

The quality of the aquaculturists’ rights over their farms plays a vital role in achieving sustainable aquaculture industry. In effect, ownership over natural resources in the light of private law is not established because it is not tradable in China. But the users’ rights over the natural resources have already been recognized under the current Chinese laws. This paper introduces concept of property rights, describes and analyzes the aquaculturists’ rights over the farms under the current Chinese laws. Because of flow of water, agricultural nature, and so-called State ownership over the natural resources, fish farms present a complicated property rights problem in China. Some flaws in the aquaculturists’ rights are identified under the existing laws. To protect the interests of farmers and to pursue sustainable aquaculture, quasi-property rights should be granted to fish farmers.

Involvement of VAMP-2 in exocytosis of IL-1β in turbot ( Scophthalmus maximus) leukocytes after Vibrio anguillarum infection

Vibrio anguillarum is a major pathogen threatening the fish aquaculture in China. Infection of cultivated turbot ( Scophthalmus maximus) with V. anguillarum induced rapid synthesis and secretion of IL-1β, which initiates the innate immune response. SNARE proteins are known to regulate vesicular trafficking and fusion in all eukaryotes. Here, we determined whether SNARE proteins, specifically vesicle-associated membrane protein-2 (VAMP-2), are involved in regulated exocytosis of IL-1β of leukocytes in marine fish. We show that VAMP-2 is present in turbot blood leukocytes, with nucleotide sequence identity of 88.2% and 93.0% to those of zebra fish and sea bass, respectively. After Vibrio infection, turbot leukocyte VAMP-2 was increased at the levels of transcription and translation in a temporal pattern coinciding with leukocyte IL-1β secretion. Confocal microscopy localized VAMP-2 to vesicle structures in leukocytes. Taken together, our results suggest that VAMP-2 is involved in regulated exocytosis of cytokines in immunocytes in fish.

Activities of selected digestive enzymes during larval development of large yellow croaker ( Pseudosciaena crocea)

Large yellow croaker is an important marine fish species for aquaculture in China. Larval rearing of this species is still based on live prey feeding. The aim of this study was to describe the onset and development of the main digestive enzymes during larval development of this species, in order to obtain essential data for the formulation of a compound diet adapted to larvae. Enzymatic assays were conducted from day 1 post hatching to day 40 in larvae fed the following live prey sequence: rotifers, Artemia nauplii, copepods, and then frozen copepods. Assays were done on whole larvae until day 19, then on dissected larvae and on purified brush border membranes of intestine. Pancreatic enzymes, amylase, and trypsin, showed high activities from early stages, even before mouth opening. Mechanisms of pancreatic secretion were achieved from day 19. Enzymes of brush border membranes, alkaline phosphatase, and aminopeptidase N, increased abruptly between day 23 and 25, showing maturation of the intestinal digestive process. These data, together with data describing mouth enlargement during development, suggest that large yellow croaker larvae could be fed successfully with a compound diet from early stages, at least from day 23.

The Development of Tiger Puffer Aquaculture in China and Export to Japan

The purpose of this study is to examine puffer (tiger puffer, ocellated puffer) aquaculture and its exports from China and the imports and handling in Japan. This should help explain the details of puffer distribution and examine the spatial structure of fishery product distribution. Producers in China began the aquaculture business of puffers in 1994. In 2000, about 1000 tons of Chinese puffers were exported to Japan. The aquaculture businesses are located in north China areas such as the Yellow Sea and Sea of Bohai. Chinese fish breeders began their business of puffer aquaculture to earn large profits since puffers are sold at high prices. Chinese puffer aquaculture has achieved mass production and low density by different methods from Japanese aquaculture, for example, the use of breeding rooms to pass the cold winters and the utilization of ponds where shrimp were previously cultured. It is necessary to take countermeasures to reduce the oversupply in the market owing to the expansion of production. Since consuming puffers is currently prohibited in China, free transactions of the sale and consumption of puffers are expected in the future as well as the establishment of domestic markets. Today, low-cost puffers aquacultured in China are acknowledged as a new factor in puffer distribution. The areas that import puffers have been expanding overseas, and the users and consumers of puffers include all types of people. The target size of puffers varies depending on the size individual consumers prefer for cooking. This type of demand for selling and consuming puffers has become a major factor regulating the distribution structure, the actions of its elements and the interrelations of such elements. Cultured fish transactions, the introduction of puffers to the food culture, and the intermediations of cultured fish transactions by marketing wholesalers are also recognized.

Economics of Aquaculture: Special Issue Introduction

During the last 25 years, aquaculture production has changed from a minor, relatively unimportant contributor to the world’s seafood supply (about 7% in 1975) to constituting about one-third of supply in 2000 (FAO 2002). This has, of course, changed seafood consumption patterns substantially, and therefore, market structure. An implication of this development is that aquaculture production, in many cases, cannot be ignored if one is interested in the functioning of seafood markets. This is true even in the case of fishery regulations. For instance, salmon and sea bass provide prime examples of how growth in aquaculture production leads to price reduction and a very different market environment for the fishermen that target these species. As noted by Anderson (2002, this issue), the distinction between a fishery and aquaculture depends, to a large extent, on the degree of control over the production process. This depends both on the migration of the stock in question and the degree of property rights. Hence, an ITQ system is closer to aquaculture than an open-access system. The distinction between a fishery and aquaculture then becomes very blurred for quite a few species, such as mussels, scallops, etc. These species, in principle, are wild and, in most cases, the breeding process is not controlled. However, when fishermen have use rights to a particular oyster bank, for example, and attempt to make the bank more productive, this is basically considered extensive aquaculture, having a number of similarities to traditional oyster aquaculture in China or France. As one gains increasing control over the production process, including breeding and feeding, aquaculture becomes more intensive and industrialized. To what extent the production process can be controlled is important with respect to planning, and thereby influences the timing and the quality of the product sold. The increased degree of control over the production process for aquaculture products has led to interest in a number of new research topics relating to seafood products on both the production and market sides, since this control enables producers to influence more parameters than in the traditional fishery. However, as new regulatory tools give fishermen increased control over their harvest, many of these topics are or will become important in studies of traditional fisheries. Moreover, their importance is likely to increase as the competition between wild and farmed seafood intensifies, and as market requirements become similar for captured and farmed seafood (e.g., in the form of ecolabels).

Environmental and Socioeconomic Constraints to the Development of Freshwater Fish Aquaculture in China

In this article, we provide an overview, on freshwater fish aquaculture in P.R. China, with special emphasis on pond fish culture. We describe the history, ecology (trophic structure and species reared), and technological aspects (including inputs/outputs, yields, labor productivity, and fossil energy use) of freshwater fish production and analyze its role in relation to the socioeconomic context. We discuss the prospects for intensification of production.In China, freshwater fish aquaculture has always been closely linked to cultivation of crops and animal husbandry, that is, feed inputs are in the form of agricultural wastes. The close integration with the farming system at large results in an efficient use of nutrients, low environmental loading, and little dependence on fossil energy inputs. About 7 to 9 different fish species, mainly herbivores, are kept in the same pond and efforts are made to maintain as much as possible the natural mechanisms of matter regulation and energy flows within the pond ecosystem. However, ecological compatibility is paid for by relatively low productivity, both per hectare of waterbody and per hour of labor input. If the throughput of freshwater fish production per unit of area and labor are to be dramatically increased, the equilibrium of the traditional integrated system will be difficult to maintain.

Biodiversity use and technical performance of freshwater fish aquaculture in different socioeconomic contexts: China and Italy

The availability of natural resources and the socioeconomic context in which aquaculture is performed condition the choice of aquacultural production techniques. In this paper, we examine and compare the pattern of biodiversity use (the ecological side of the production process) and the technical coefficients (the economic side of the process) that characterize freshwater aquaculture in PR China and in Italy in relation to the role that freshwater aquaculture plays in these societies. The comparison between aquaculture in China and Italy covers the following aspects: (1) history and general statistics of aquaculture; (2) cultivated species and trophic structure of managed freshwater ecosystems; (3) technological characteristics of the production process, including inputs/outputs, yields, labor productivity, and fossil energy use; (4) role of freshwater aquaculture in relation to its socioeconomic context. In Italy, where socioeconomic constraints (high opportunity cost of labor and a food system dealing with a surplus of nutrients) overwhelm ecological constraints (through imports and technology), freshwater aquaculture operates with densities of nutrient flows outside the range typical of natural aquatic ecosystems. Freshwater bodies used for production are artificial and generally contain only one carnivorous species that depends for its survival on human management of inputs and waste disposal. In contrast, in China, up to nine different species (mainly herbivores) are kept in the same pond, and efforts are made to maintain as much as possible the natural mechanisms of regulation of matter and energy flows. This results in higher efficiency in terms of use of biological energy (from biological cycles) within the system, lower environmental loading, and less dependence on fossil energy inputs. However, the better biophysical performance of Chinese aquaculture is linked to low labor productivity. This makes it difficult to adopt such an ‘ecologically friendly’ solution in developed countries, such as Italy, where the opportunity cost of labor is high.

Cage culture development and its role in aquaculture in China

. This paper is divided into four parts. First, history: cage culture has long been practised. The origin of cage culture world-wide should be regarded as the middle reaches of the Yangtze River, China, in the Sung Dynasty. Second, characteristics of cage culture in China. Third, influence: development of open-water fisheries is actively promoted in lakes, reservoirs and rivers. More kinds of water bodies have been employed for this purpose. Marine cages have also rapidly developed. Finally, discussion and conclusions. Cage culture is a modern development of aquaculture which has changed the long-established, fish-farming structures and, to a great extent, pushed forward fisheries development in China. Cage culture is typically characterized by intensive farming, running-water culture, high yield and great efficiency. It is generally accepted that cage culture will actively play an increasingly important role in international aquaculture.

The Household Responsibility System in China's Agricultural Reform: A Theoretical and Empirical Study

The emergence and eventual prevalence of the household responsibility system, which replaces the production team system as the unit of production and income distribution, has brought about dramatic changes in China's rural areas since 1979. This institutional change has resulted in remarkable growth in agricultural productivity.' However, in the literature on collective farms, a theory that is capable of explaining the causes and effects of this change is yet to be developed. The formal theory about collective economies developed so far by Ward, Domar, Sen, Oi and Clayton, Bradley, Maurice and Ferguson, Cameron, Bonin, Chinn, Israelsen, Putterman, and others suggests that the allocation of resources in a collective farm is efficient at least in