bluuebunny/crossref_metadata_2025 huggingface dataset:
La carpe commune (Cyprinus carpio) au Cameroun: historique et description de différentes pratiques de reproduction et d'élevage dans l'Ouest et le Nord-ouest Cameroun.
Authors: François Christophe , Ndjonjip Yves Merlin
Published: April 2021

Introduced in Cameroon from the 1970s from the USA (Israeli strain), carp production has evolved into a real roller-coaster ride. The control of its breeding began with attempts at reproduction, first natural and then artificial. Apart from the IRAD station in Foumban and the GIC AIO in Batié, artificial reproduction is not implemented anywhere else. Raising of this species is most common in the western highlands region. It is done in polyculture with tilapia and sometimes catfish and this at low density. With a diet based on fertilization of ponds supplemented with a few agro-industrial by-products, the final average weights and yields meet the expectations of producers. Among the barriers to the expansion of this species, we note the unavailability of carpillons throughout the year, the damage caused by this species on the dikes, and finally the characteristics of the flesh which do not seem to be very popular with consumers.
The role of fish farmers associations in aquaculture development in Uganda: case study of Walimi Fish Farmers Cooperative Society.
Authors: Walakira John K , Isyagi Nelly A , Ssebusubi Maurice , Leschen William
Published: April 2021

The fisheries sector in Uganda provides employment, boosts national foreign exchange earnings, and offers a healthy source of protein. Main challenges facing the expansion and sustainability of the sector range from declining fish stocks in the natural water bodies to inconsistent supply to market chains. Development of aquaculture offers great potential to boost Uganda's fish processing capacity but is still limited by a poorly established supply through the market chain. Public-private partnership initiatives have reorganized fish farmers into viable groups that are focusing on filling gaps, thereby directly increasing economic and social benefits, especially to rural communities. Through WAFICOS, a fish farmers association formed in 2004, private sector linkages have been strengthened, fostering aquaculture development in Uganda. Since its formation in 2004, privately operated hatcheries have addressed problems of fish seed availability. The association has created markets for farmed fish products, thus stimulating aquaculture production. Members of WAFICOS, in March 2010, numbering 315, have direct access to advisory services, appropriate technologies, farm inputs, markets and credit facilities. This case study should be read as an illustrative example of how such a fish farmers' association was conceived, set up and its management and working infrastructure developed. From 2008, the Cooperative was supported and advised by the USAID Fish Project, very much with the objective of being a financially self-sustaining organization. Since its inception there have been a number of lessons learned from successes and failures. Time will tell whether the organization continues to develop and can remain financially viable to benefit its members.
A case study on the experiences of innovative, small-scale fish farmers in Malawi.
Authors: Valeta Joshua M H S
Published: April 2021

The Innovative Fish Farmers Network Trust (IFFNT) comprising of 25 farmers was established as part of the Master Plan Study on Aquaculture Development in Malawi (ADiM) with funds from the Japanese International Cooperation Agency (JICA) in 2004. ADiM aimed at promoting aquaculture development by establishing model farmers through financial and technical support from JICA and the Department of Fisheries (DoF). Farmers attended training facilitated by Bunda College, University of Malawi, and farmer exchange and study tours to Zambia and Egypt. They also received small grants to implement pilot on-farm projects. Production increased from about 0.7 tons/ha/year in 2003, to over 2 tons/ha/year in 2005. Other farmers adopted the technologies. However, as ADiM phased out in 2006, IFFNT became dormant. Its linkages with DoF weakened. There was no proper phase out strategy. Both ADiM and DoF needed to facilitate IFFNT until it was properly established; a change that should be adopted in any future IFFNT facilitation.
Case study on developing financially viable Recirculation Aquaculture Systems (RAS) for tilapia production in Egypt: technology transfer from the Netherlands.
Authors: Radwan Ismail A
Published: April 2021

This case study describes the first trial operation of a recirculating aquaculture system (RAS) for tilapia production in Egypt. The fish farmer in this case study became involved with an exchange programme with the Netherlands, resulting in wholesale changes in his commercial farm which are described in this case study. Also presented is a cost benefit analysis of the results of the first trial.
Working with the private sector in aquaculture development - the experience of GNAEP.
Authors: Mowhila Reshad
Published: April 2021

Since 2002 the Greater Noakhali Aquaculture Extension Project (GNAEP) has been promoting rice-prawn (giant freshwater prawn, Macrobrachium rosenbergii) culture as a means of adding value to small-scale aquaculture systems in southeast Bangladesh. Over a period of two years there has been a rapid expansion of this culture system, crucial to which has been the development of partnerships between GNAEP and the private sector. Through a process of dialogue and confidence building, GNAEP has persuaded local businessmen to invest in prawn hatcheries, manufacture of fish meal (ground, sun-dried fish) bought directly from artisanal fishermen on Hatiya Island and in setting up a prawn purchasing center. These partnerships have supported the Project's primary objective of improving the livelihoods of the rural poor, through ensuring supplies of cheap post-larvae, partly as credit in kind, to farmers, through releasing poor fishermen from exploitative relationships with local money lenders and through creating competition in the local market. The influence of the private sector on local and national policy makers has been another advantage from the system.
Typology of farming systems in brackishwater ponds in the Philippines.
Authors: Irz Xavier , Stevenson James R.
Published: April 2021

To classify brackishwater pond farming systems in the Philippines, a farm-level survey in the two main production regions (Central Luzon and Western Visayas) produced input and data for principal components analysis and cluster analysis to generate a typology of farming systems. A solution of five farm types is described in detail and interpreted. The implications for comparative analysis of sustainability impacts are described.
Vac systems in the Mekong Delta, Vietnam.
Authors: Pham Cu Thien
Published: April 2021

VAC systems are an integration of garden (vuon), pond (ao) and animal pen (chuong). VAC farming systems can be classified into different types on the basis of the uses and intensity level of orchard and pond. Fruit trees include citrus, longan, mango and sapodilla, and vegetables include cassava, centella, sweet potato and water spinach. Livestock are poultry and/or pigs. A fish polyculture is practised with species such as silver barb (Barbonymus gonionotus), Indian major carps (mrigal, Cirrhinus cirrhosus, and rohu, Labeo rohita), silver carp (Hypophthalmichthys molitrix), grass carp (Ctenopharyngodon idella), giant gourami (Osphronemus goramy), river catfish (Pangasianodon hypophthalmus), hybrid catfish (Clarias macrocephalus × C. gariepinus), common carp (Cyprinus carpio), kissing gouramy (Helostoma temminckii) and Nile tilapia (Oreochromis niloticus). Pig manure is commonly used as fertilizer for crops while rice by-products are mainly used to feed the livestock. Major inputs for ponds are on-farm resources (crop residue, grass, fallen fruit, rice by-products, human waste, poultry manure, urine and washing from the pig sty) for the low input systems, and off-farm feeds (trash fish, fish meal, golden snail) for medium and high input aquaculture systems. Fish production is below 2 t ha-1 year-1 in the low input and 2-10 t ha-1 year-1 for medium and high input aquaculture.In general, VAC farming in the Mekong Delta is practised in a medium farm with an average pond area ranging from 500 to 1,000 m2, producing fish at less than 1 t yr-1, of which about 250 kg is for family consumption and the surplus, if any, for sale is insignificant. As VAC still has many problems and constraints, an appropriate way to develop VAC farming in the Mekong Delta is to provide farmers with farm component technologies and management knowledge.
Trials of cage fish culture in Ea Soup reservoir, Dak Lak province, central highlands of Vietnam.
Authors: Truong Ha Phuong , Phan Dinh Phuc , Phan Thuong Huy , Sollows John
Published: April 2021

Reservoirs in the Central Highlands of Vietnam are numerous and growing in number. Most of these reservoirs were built mainly for irrigation, with flood control and occasionally, hydroelectricity as secondary functions. Ea Soup reservoir covers an estimated 240 ha at the upper storage level, and has a drawdown of only 2.5 m. Probably for this reason, there is an abundant supply of macrophytes in the reservoir. While a number of species have cage culture potential, grass carp (Ctenopharyngodon idella) is particularly popular in many parts of Vietnam. The species feeds almost entirely on macrophytes, so cash requirements for feed are minimal. This is suitable for most poor farmers in the area. The market price, about VND 15,000 kg-1 (US $1=VND15,000 approximately) is higher than that for many species. In Ea Soup reservoir, cage culture of grass carp commenced in 1993, and rapidly expanded. By 1996, there were 152 cages. Stocks were hit by disease, and were decimated late in the year. These losses were a strong discouragement to continuation of the practice. Many owners suffered heavy financial losses. Pollution, poor circulation in the cages, high stocking density and overcrowding of cages may have contributed to the disease problem. From June 1998, the Project, jointly with three fishers has tested the culture of grass carp combined with small numbers of Nile tilapia (Oreochromis niloticus) and common carp (Cyprinus carpio) in cages with new materials, somewhat larger mesh size, and lower stocking density. The economic viability of this modified technology will depend mainly on the lifetime of the cage. Nevertheless, fishers are continuing to culture at their own expense. This suggests that the technology has some sustainability in the reservoir. The extent to which cage culture can be practiced remains to be seen, but any expansion must be done with caution.
Trash fish utilization in aquaculture in Vietnam.
Authors: Le Anh Tuan
Published: April 2021

There is concern that the rapid expansion of aquaculture may be constrained in future by increasing dependence on low-value marine trash fish and fishmeal. According to Vietnamese Government plans, aquaculture production for 2006 and 2010 will be 1.15 and 2.00 million t, doubling and tripling of the 1995 figure of 0.65 million t, respectively. A study on which this case study is based described the production, uses and trends of trash fish in Vietnam to assess if its availability will restrict future expansion of aquaculture in the country. Field visits and interviews were carried out in some coastal provinces as well as in Hanoi and Ho Chi Minh cities in February 2003. There are conflicting data on the volume of trash fish landed. Although the inshore fishery in Vietnam is heavily fished, the total fish catch, as well as the proportion of biomass of trash in the total catch, continues to rise. There has been a dramatic rise in the use of trash fish in aquaculture but there are competing uses for trash fish for livestock feed, fish sauce and direct human food. It is unlikely that aquaculture based on traditional use of trash fish as a direct feed can expand considerably. The future expansion of marine crustaceans and finfish culture in Vietnam will depend increasingly on formulated pelleted feed and on imported fish meal and fish oil.
Small-scale pond aquaculture in Kishoreganj, Bangladesh.
Authors: Edwards Peter
Published: April 2021

This case study was prepared as part of an Asian Development Bank (ADB) Special Evaluation Study (SES) on Small-Scale Freshwater Rural Aquaculture for Poverty Reduction. The SES used primary and secondary data and published information to document the human, social, natural, physical and financial capital available to poor people involved in the production and consumption of freshwater farmed fish and to identify various channels through which the poor are affected, such as through access to livelihood assets, markets and prices, and access to services and facilities. This case study was tailored to highlight the operating environment of small-scale fish farmers in rural Bangladesh, and their livelihood profiles.
Small-scale farming of tilapia in ponds in Central Luzon, Philippines.
Authors: Edwards Peter
Published: April 2021

This case study was prepared as part of an Asian Development Bank (ADB) Special Evaluation Study (SES) on Small-Scale Freshwater Rural Aquaculture Development. In the context of the SES, this case study used primary and secondary data and published information to document the human, social, natural, physical and financial capital available to households involved in the production and consumption of freshwater farmed fish and to identify channels through which the poor are affected. This case study describes first the history, biophysical, socioeconomic, and institutional characteristics of Central Luzon, followed by accounts of the technology and management for farming tilapia, with detailed profiles of fish farmers and other beneficiaries. Transforming processes are discussed with respect to markets, institutions, support services, policy and legal instruments, natural resources management, and environmental issues.
Small indigenous fish species of Bangladesh - potential for culture and conservation.
Authors: Wahab Md. Abdul , Alim Md. Abdul , Uddin Md. Sharif
Published: April 2021

The possibilities of conservation and production potential of a large number of small indigenous fish of Bangladesh through aquaculture remains unexplored. Only a small number of carps has been used for polyculture throughout the country which provide employment for a large number of people in the domestic fish marketing chain as farmers, traders, intermediaries, day labourers and transporters. Special attention is needed for the culture and conservation of small indigenous species (SIS) because they are an important source of vitamin A and minerals. SIS used to be abundant in rivers, streams, beels (deeper portions in low-lying natural depressions), ponds, ditches and flood plains in the past, but have gradually been disappearing from natural systems, which in turn severely affects biodiversity.
Social development and human rights - child labour in aquatic products production and processing.
Authors: Monir
Published: April 2021

Shrimp plays a significant role in the development of the national economy of Bangladesh. Farmers in Bangladesh have chosen bagda (Penaeus monodon) for coastal aquaculture due to its high export value in the international market. Therefore, coastal poor people have collected wild bagda post-larvae (PLs) for the last two decades. It is estimated that about 12,890 children are permanently and/or temporarily engaged in shrimp seed collection in greater Barisal and Khulna districts, of whom 76% (9,750) are girls and 24% (3,140) are boys. In Cox's Bazar and greater Noakhali districts, 1,590 children are engaged in this job, with 21% (340) girls and 79% (1,250) boys. Another 10,000 children are involved in shrimp and fish catching, sorting and drying in Dublarchar island, located 170 km south of Khulna city. It is also located 180 km from the Mongla port in Bagerhat district which is used as a fish landing centre. In addition, more than 1,500 children are also engaged in collecting snails and clams, which are used as a popular feed, particularly for galda chingri (Macrobrachium rosenbergii).
Shrimp-Artemia-salt integrated system, Vietnam.
Authors: Nguyen Van Tien
Published: April 2021

Traditional solar salt pans appeared in Vinh Chau, Soc Trang province and Bac Lieu province in the 1960s (Do, 1998). Crude salt is mainly used for human consumption and to salt fish and fish sauces and therefore its demand is not considerable. Moreover, a large amount of crude salt was produced yearly at the sites which exceeded local consumption needs. Consequently, all salt produced could not be sold which reduced the income of salt farmers. Towards the end of the 1980s, an Artemia culture technique in salt pans for cyst production was developed by the College of Aquaculture and Fisheries (CAF), Cantho University, which proved to be more profitable than traditional salt production (Vu, 1997). Therefore the technique was immediately transferred to farmers and the production scale increased year by year. This case study describes the system of shrimp, Artemia and salt production which was introduced to salt farmers with the aim of developing a new production system to help to improve their living standards.
Shrimp and prawn post-larvae collection and impacts in Bangladesh.
Authors: Shelly Anwara
Published: April 2021

Fry collection of tiger shrimp (Penaeus monodon) and giant freshwater prawn (Macrobrachium rosenbergii) fry from wild aquatic resources is a regular practice among the poorer section of the coastal communities in Bangladesh. In the early stages of aquaculture development, shrimp culture was limited to a few areas but the growing demand for shrimp on the international market has opened an avenue for many new entrepreneurs. Until recently, shrimp farmers stocked only wild fry on their farms. Fry collectors found this emerging sector a good additional source of income and successively made it their major livelihood. Concerns over the effect of this practice on biodiversity prompted the Government to ban fry collection, thus threatening the livelihood of fry collectors.
Seed production technology and culture system of snakeskin gouramy (Trichogaster pectoralis) in Vietnam.
Authors: Dung Nhat Lung
Published: April 2021

Snakeskin gouramy (Trichogaster pectoralis) is a high-value fish species in the Mekong Delta of Vietnam. It is naturally distributed in Bac Lieu, Ca Mau and Kien Giang provinces but production from natural water bodies has declined significantly. Snakeskin gouramy can be cultured in monoculture or polyculture, in ponds or rice fields. Artificial reproduction of the fish was studied using different doses of human chorionic gonadotrophin (HCG) and pituitary gland. At a dose of 1,000-1,500 UI of HGC and 0.54 mg of pituitary gland, fish spawned after 18-19 h at a water temperature of 27-28°C. Fish can re-mature 3-4 times per year. Fry was nursed at a density of 300-900 fry m-2 with survival rate of 75-78%.
Seed production and grow-out of sand goby (Oxyeleotris marmoratus) in Vietnam.
Authors: Pham Van Khanh
Published: April 2021

Pond area for broodfish ranges from 500 to 1,000 m2 with a depth of 1-1.2 m. Broodfish density ranges from 0.2 to 0.3 kg m-2. Fresh food such as snails, small prawns and fish are used to feed broodfish at a feeding rate of 3.5% of total body weight per day. Water exchange is done periodically at 20-30% of total volume per time. Sticky eggs of sand goby adhere to substrates. Hatching takes place 22-48 hours after fertilization. A suitable temperature is 28-29°C and pH at 6.5-7.5. Nursing fry to fingerlings is carried out in ponds at a stocking density of 300-500 fish m-2. After nursing for 50-60 days, they can reach the size of 3 cm. Large fingerlings of 15-30 g are obtained after at least 3 months of nursing. Continuing nursing up to 5-6 months gives larger fingerlings (60-80 g) for grow-out. Stocking density is 5-10 fish m-2 in grow-out ponds and 30-40 fish m-2 in cages. Fish, small prawns, snails and by-products from slaughterhouses are used to feed the fish. They can reach a marketable size of 500 g or more after 6-7 months of culture.
Seed production and culture of abalone in Vietnam.
Authors: Luu Duc Minh
Published: April 2021

This paper presents the techniques of seed production and culture of abalone (Haliotis asinina) using three methods: cage culture in concrete tanks, cage culture in the sea and bottom culture on a rocky beach. These are the results of a study carried out for many years by the Ministry of Fisheries of Vietnam. Based on the results obtained, commercial seed production and transfer techniques of seed production of abalone in four provinces, Khanh Hoa, Ninh Thuan, Phu Yen and Quang Nam, are being carried out.
Rice-fish culture in China.
Authors: Yi Yang , Wu Zong-wen
Published: April 2021

Modern rice-fish culture in China fully explores the large space of rice field and water resource, while ensuring minimal compromise to rice production to increase fish production and profitability through increasing investment in infrastructure, stocking large fish fingerlings, using high-value species, applying commercial artificial feed, flexible harvesting, and integration with fruit and vegetable crops on the dike. A well-managed rice-fish culture system can produce 6,000-7,500 kg rice and 1,500-7,500 kg fish ha-1 year-1, depending on fish species and system configuration used, and generate an income 2-20 times as high as that of rice cultivation alone. Rice-fish culture plays an important role in improving the economic status of rice farmers in China.
Rotation farming of rice and shrimp in the Mekong Delta, Vietnam.
Authors: Truong Hoang Minh
Published: April 2021

Rotation farming of rice and shrimp is a typical farming system in the Mekong Delta of Vietnam, where saline water intrusion takes place seasonally. In this area, shrimp (Penaeus monodon) culture is carried out during the dry season and rice is cultivated during the rainy season. The growth, survival rate, water quality variation and cost: benefit ratio of the system were monitored in three experimental shrimp farms (1-1.3 ha per pond) in Soc Trang province and three others (0.4-0.5 ha per pond) in Bac Lieu province. The water quality did not vary much; the growth rate was 0.23 to 0.29 g day-1, average survival rate reached 89%, average shrimp yield was 392 kg ha -1 and the cost: benefit ratio was 1:4.6 to 4.8. However, white spot syndrome virus (WSSV) occurred in the farming system, especially in seasonal transition (dry and wet season).
Remote sensing to assess shrimp farming development in Haiphong, Vietnam.
Authors: Giap Dao Huy
Published: April 2021

Remote sensing (RS) was used to detect land use changes caused by shrimp farming and other activities, to examine the status of shrimp farming, and to recommend a management guideline for sustainable shrimp farming development. The study was conducted at Doson and Kienthuy districts of Haiphong, Vietnam, during June-December 2002. Three images for dates in 1990, 1995 and 2000 were used. The images were radiometrically normalized and geometrically registered to a UTM map projection. Each image was separately classified into different categories of aquaculture ponds, agricultural land, salt farms, village mixed orchards, urban and build-up land, mangroves, rangeland, hill-land forest and open water. Visual image classification in conjunction with associated topographic maps and related reports was employed on all images. The classified images produced were analysed for changes in each land use category by overlaying them in a geographical information system (GIS) framework. The results indicated a significant increase of mangrove area from mudflat area and shrimp pond area from agricultural land and salt farms. Shrimp pond area increased rapidly from 491 ha in 1990 to 607 ha and 1,690 ha in 1995 and 2000, respectively. The study suggests that the growth of shrimp aquaculture must be done on a regulated basis to minimize environmental degradation and guide shrimp farming development towards the sustainable use of coastal resources.
Research on supplementary feeding for production of Nile tilapia.
Authors: Diana James
Published: April 2021

Efficient supplementary feeding will utilize not only the feed added to the pond, but also natural food. Feeding improves the growth rate of fish in a pond only when the fish are food limited. Natural foods may provide all of the necessary nutrition for normal growth of small fish, and if growth begins to decline at a larger size, supplementary feeding should yield higher growth rates. One experiment compared the use of fertilizer alone, feed alone, and a combination of feed and fertilizer for growth and production of Nile tilapia (Oreochromis niloticus). Ponds receiving feed and fertilizer had higher growth rates than ponds with feed alone, and both showed considerably higher growth rate than ponds with fertilizer alone. Feeding was necessary to grow fish to a size of over 200 g in a reasonable amount of time. A second experiment tested the possibility that feeding at reduced ration and allowing the consumption of natural food might give a comparable growth rate to feeding alone. In this experiment, full satiation ration, 75% satiation ration, or even 50% satiation ration resulted in similar mean weights at harvest, about 400 g after 150 days. These results indicate that it may be efficient to simply feed the fish at about half of their maximum ration and allow them to eat natural food for the other half of their growth, if the pond is managed well. Economic analysis showed that fertilization resulted in $1,891 ha-1 year-1 of profit, feed only lost almost $3,000 ha-1 year-1, 75% feeding lost $258, 50% feeding yielded $1,765 ha-1 year-1, and 25% feeding yielded $155 ha-1 year-1. If the growth rate were linearly extrapolated until the fish reached 500 g and were then harvested, the 75% feeding would yield $4,835 ha-1 year-1 and the 50% feeding $5,865 ha-1 year-1. A third experiment was conducted to evaluate the timing when first feeding should occur. In this case, fish in ponds were fed once they reached 50, 100, 150, 200 or 250 g in size. The fish grew similarly before they were fed, and then grew again similarly after feeding, with a growth rate under fertilization of about 1 g day-1, and a growth rate under feeding of about 3 g day-1. Fish fed first at 50 or 100 g reached the same ultimate size by the end of the experiment and had similar production levels. Fish first fed at 150 or 200 g also showed similar results and, finally, fish fed at 250 g never reached the targeted size. These results indicate that it is most efficient to wait until the fish reach 100 g before commencing artificial feeding. Economic evaluation showed an annual net profit of $3,700 ha-1 year-1 when the fish were fed first at 50 g, $6,160 at 100 g, $4,800 at 150 g, $1,800 at 200 g and $3,600 at 250 g. Clearly, efficient feeding systems produce higher incomes than less efficient systems, and fertilization alone, if the fish reach a targeted size that has a higher economic value.
Propagation and cultivation of Gracilaria in China.
Authors: Delin Duan
Published: April 2021

Gracilaria has a long history of cultivation and utilization in China and is now widely cultured in ponds and tanks in the coastal area. G. tenuistipitata var. lui and G. lemaneiformis are the two main species cultivated. Spore collection and micropropagation are used for providing seed of Gracilaria. Ground planting and raft cultivation are the two main culture methods. Polyculture with fish, shrimp and filter-feeding bivalves is also practised in many locations. Strain selection and genetic analysis are conducted for both wild and cultured strains.
Polyculture of the sea cucumber (Holothura scabra) with tiger shrimp for water quality improvement.
Authors: Thai Ngoc
Published: April 2021

This case study describes research on the polyculture of the sandfish (Holothuria scabra) and tiger shrimp (Penaeus monodon) to improve pond water quality. At the first location in Khanh Hoa province, three 1,200-m2 ponds were stocked with shrimp postlarvae (PLs) at a density of 30 PLs m-2. Two ponds (S4 and S3) were stocked with sandfish, at 50 and 100 g m-2, while no sandfish was stocked in the control pond (S2). At the second location also in Khanh Hoa province, three 450-m2 ponds were constructed and stocked with shrimp PLs at a density of 30 PLs m-2. Two of these ponds (S5 and S6) were stocked with sandfish at 50 and 100 g m-2, while no sandfish was again stocked in the control pond (S7). A higher stocking density of sandfish generated a higher growth rate of shrimp (one -way ANOVA, p=0.15, n= 50). The growth rate of shrimp increased with sandfish stocking density, from 0.036 to 0.057 to 0.067 g per day at sandfish stocking densities of 0, 50 and 100 g m-2, respectively. Increasing sandfish stocking density also reduced the hydrogen sulphide (H2S) concentration (one-way ANOVA, p<0.05, n=89). Likewise, concentrations of nitrite (NO2-N), and total organic compounds were higher in systems not stocked with sandfish (one-way ANOVA, p<0.05, n=50). Fungal and bacterial densities decreased with increasing sandfish stocking density. This study thus showed that sandfish could remove certain quantities of toxic gases, organic compounds and microorganisms from shrimp culture systems.
Pond culture in the Red River Delta, Vietnam.
Authors: Edwards Peter
Published: April 2021

The Red River Delta (RRD) in north Vietnam, one of the most densely populated areas in the world with over 1000 people per km2, has a traditional small-scale integrated farming system known locally as VAC in which a polyculture of carps is raised in household-level ponds in association with livestock and crops. VAC is an acronym for the Vietnamese words for garden (vuon), pond (ao) and livestock quarters (chuong). There are diverse linkages between VAC subsystems which vary with agroecological zone. The importance of VAC has long been recognized for household food security and increasingly as a source of income as the rice-based economy is diversified. Research with farmers has improved the efficiency of use of on-farm and locally available resources in VAC with extrapolated fish yields of 3-4 t ha-1 in the 700-1000 m2 ponds, giving cost:benefit ratios of 1:2.7-2.8.
Pond culture of the freshwater prawn Macrobrachium nipponense in China.
Authors: Yi Yang , Wu Zong-wen
Published: April 2021

In China, conditioning of freshwater prawn (Macrobrachium nipponense) broodstock is conducted in earthen ponds at a density of 45-60 g m-2, at a ratio of 3-4 females to 1 male (Liu, 2004). Mixed feed and fresh food of animal origin are used for broodstock. Mating occurs when temperature rises above 18°C. Gravid prawn are stocked in cages at a density of 0.5 kg cage-1. After 20-25 days, prawn larvae hatch. Nursing is done in earthen ponds at a density of 2,000 prawns m-2. When the larvae grow to 0.8-1.0 cm long, the density should be reduced to 1,000 prawns m-2 or lower. After nursing for 20-30 days, when the prawns reach more than 1.0 cm, they can be stocked in grow-out systems. Two crops are possible in one year in south China and one crop in the north. Commercial feeds containing 35-40% crude protein are used to feed prawns.
Potential of seaweed culture on St Martin's Island, Bangladesh.
Authors: Salam Md. Abdus
Published: April 2021

Seaweeds grow abundantly along the Sundarban coast and St. Martin's Island. Twenty-two kinds of seaweed have been recorded in the coastal waters of Bangladesh, most of them from St. Martin's Island. St. Martin's Island, Ukhia and Teknaf Upazilla and the sheltered coast of the Bay of Bengal and its surrounding area have potential for seaweed culture. Moreover, the physico-chemical properties in the area are also suitable for seaweed culture. Presently, fishermen, women and children on St. Martin's Island are engaged in seaweed collection, drying and selling to middlemen who smuggle it to Burma. The communities benefit little and the Government does not gain revenue from these activities. Seaweed culture could provide an alternative livelihood for poor fishermen and help to develop seaweed business, which would increase export revenue for the Government. Furthermore, the environment and biodiversity would be safeguarded, as seaweed culture is environmental friendly.
Potential of seaweed farming in Bangladesh.
Authors: Zafar Mohammad , Kamal Dipak
Published: April 2021

St. Martin's Island and certain parts of the mangrove area of Bangladesh are suitable for seaweed farming. More than 185 species of seaweed have been reported from the coastal area of this country. For the first time, four species (Catenella nipae, Caulerpa racemosa, Enteromorpha sp. and Hypnea sp.) have been experimentally farmed on St. Martin's Island and at the Fauzdarhat mangrove area by the line, rope, raft and suspended rope methods. Although seaweeds are not consumed in the country, they have good demand in foreign markets. Considered as a livelihood option for rural coastal people, seaweed farming could provide an alternative source of income and protein.
Periphyton-based aquaculture.
Authors: Wahab Md. Abdul , Alim Md. Abdul , Uddin Md. Sharif
Published: April 2021

Periphyton, the assemblage of attached aquatic plant and animal organisms on submerged substrates, has the same functions of oxygen and feed production as phytoplankton, but may be more stable and can be utilized more efficiently by fish. In experiments carried out at the Bangladesh Agricultural University in Mymensingh, Bangladesh, 1.7 times higher production of rohu (Labeo rohita) and 1.8 times higher production of kalibaush (L. calbasu) were found with additional substrates. The studies on fish production with periphyton so far made have shown mixed results, but there is potential for considerable benefit.
Patuakhali-Barguna Aquaculture Extension Project - community-based fisheries management & gender roles.
Authors: Mowla Runia , Kibria Md. Ghulam
Published: April 2021

The emphasis of the Patuakhali-Barguna Aquaculture Extension Project (PBAEP) in Bangladesh is on community-based fisheries management (CBFM) in coastal areas through Integrated Pond Farming (IPF) activities. Women play an important role in IPF activities in the project area. The project stresses the development of the primary capabilities for the women's community, initially with aquaculture techniques. The project has built-up these women's groups significantly. As with other projects, PBAEP integrates gender issues in many of its policies and programmes. This case study aims to identify the problems and challenges to implementing gender mainstreaming. Daily time use and division of labour for integrated pond farming indicated that fish farming requires additional time and labour which a woman may not have, yet women were to some extent more involved than men in pond farming activities, despite labour and time not being available to them. Men enjoyed more leisure periods, as there was a huge absence of co-sharing of household chores because of the cultural attitude that all of them are the female's duty and responsibility. Women were usually reluctant to attend training programmes and to be knowledgeable on the basic concepts of fish farming training. Women are less confident to speak up in the presence of their male partners in training and meetings conducted by the project. The extension workers are also still confused about gender knowledge and the gender gap. The research findings conclude with recommendations to provide credit, form sex separate groups, and to provide extensive gender training with a gender flipchart, avoiding any social conflict for extension workers and farmer groups.
Pen aquaculture in Bangladesh.
Authors: Akhter Jubaida
Published: April 2021

The status of pen culture in Bangladesh is evaluated and the results of experimental pen culture conducted by the Riverine Station, Chandpur, of the Bangladesh Fisheries Research Institute (BFRI) are presented. Pen construction materials and their probable longevity, pen size, fish species selection, stocking density, ratio and size, method of fertilization, feed ingredients and feeding schedule, management approach and production economics are highlighted. Encouraging production was obtained with Indian major carps, common carp, Chinese carps and silver striped catfish. A community-based management approach was suitable for pen culture. Both government (GOs) and non-government organisations (NGOs) are involved with pen culture practice. Rapid and mass extension of the technology indicated that it is a sustainable technology for fish production in Bangladesh.
Pen culture of Macrobrachium rosenbergii in rivers in Vietnam.
Authors: Vu Nam Son
Published: April 2021

Pen culture of Macrobrachium rosenbergii in rivers has been developed in upstream provinces (An Giang, Can Tho and Dong Thap provinces) of the Mekong delta, Vietnam, since the early 2000s. Prawn pens of bamboo, wood and fine nylon netting, were built along the shallow margins of rivers and canals. The average size of pens was 209 m2 (35-900 m2). Prawns were monocultured, and stocked at an average density of 61.7 pieces m-2 in June and harvested 2-4 times starting from 4 months after stocking until late December or January. Most (96.14%) prawn seed were caught from the wild, while only 3.86% were hatchery-produced. All farmers fed prawns with farm-made feed, which was prepared from locally available ingredients such as snails, mud crabs, trash fish, rice, coconut flesh and cassava roots. Average prawn yield was 522 kg 1,000 m-2 year-1. Average net return was US$ 711.00 1,000 m-2 year-1. The top five constraints for prawn pen culture were disease, lack of capital and culture technologies, and poor quality of wild seed and poor water quality.
Oyster culture (Crassostrea lugubris) in Lang Co Lagoon, Vietnam.
Authors: Ha Le Thi Loc
Published: April 2021

Grow-out culture of oyster (Crassostrea lugubris) is developing spontaneously at Lang Co lagoon (Thua Thien Hue province). Various culture systems are used: culture on cement block stakes as a holdfast connected to a trellis, culture in a small cage hanging on a trellis, culture on wooden stakes (bamboo or cajeput stakes), culture on rubber tyres, and culture on stones. The culture depth differs depending on the culture style: about 4-6 m on a trellis and 1.5-2 m on wooden stakes and on stones. The chosen substrate is muddy bottom or muddy sand. The salinity of the culture area is 4-5‰ in the rainy season and 27-30‰ in the dry season. Oyster seed is collected from the wild, two times per year: in April and July. The culture duration is prolonged, at about 10-12 months. The commercial size of oyster is 9-11 cm long and about 200 g per piece. The price of commercial oyster is VND 5,000 kg-1 (about US$ 0.30 kg-1).
Networking for rural development - the evolution of communications in the STREAM initiative.
Authors: Haylor Graham
Published: April 2021

To improve the impacts of efforts in support of poorer people with limited access to services, the Network of Aquaculture Centres in Asia-Pacific (NACA) launched the Support to Regional Aquatic Resources Management (STREAM) Initiative. Four interlinked themes (livelihoods, institutions, policy development and communications) support a poverty-focused development agenda. Aquatic resources management is considered in the context in which poor people make choices about resources they can command and the circumstances in which they can be woven into a supporting livelihood. This way of working is being shared with institutions through networking, partnerships, collective learning and maybe sometimes a little peer pressure. The initiative seeks to negotiate an arbitrating role with policy-makers and people, to give stakeholders a voice in policy processes. We aim to bridge communications gaps between farmer's aspirations and potentially useful policies and service provision, and among neighbouring communities, provinces and countries to share meanings across countries and languages.
Nile tilapia and common carp fingerling production in northwest Bangladesh - a decentralised concept.
Authors: Barman Benoy
Published: April 2021

In the northwest of Bangladesh farming households in rural areas successfully produce large size fingerlings of a good strain of Nile tilapia (Oreochromis niloticus; GIFT strain) and common carp (Cyprinus carpio) in irrigated spring rice fields. The technical details of household-level fingerling production are presented as guidelines for use by extension workers for its promotion. The production of such large size fingerlings creates demand from grow-out farmers to whom they sell the fingerlings for income as well as to stock in their own ponds or rice fields for food fish production. The system thus benefits large numbers of small-scale producer households in rural areas by providing extra income and improving household nutrition. The technology is being readily adopted by farmers in rural areas after its initial introduction and with minimum institutional support. The use of such a "decentralised system" of fingerling production results in the production of small numbers of fingerlings by individual households and is mostly adopted by small and marginal farmers rather than the rich. However, for marginal and poor farmers it provides a significant proportion of their income from the rice plot and contributes an important proportion of their total household income. As a large number of households have adopted the system, the total production of fingerlings is quite high and in the northwest region where it has largely been promoted to date such decentralised production comprises almost 10% of the total fingerling production. If the production of large size fingerlings is considered, it covers a higher proportion of total fingerling production, and for fish such as the good strain of Nile tilapia, such production covers almost 100% as there is almost no production of their fingerlings in established hatcheries and nurseries in the northwest region. It also covers a high proportion of the total production of common carp because the large size fingerling production of the species in established hatcheries and nurseries is limited.
Mixed-sex tilapia culture model for sub-tropical Nepal.
Authors: Shrestha Madhav
Published: April 2021

Tilapia culture is recent in Nepal, where the subtropical zone allows a 10-month growing period. Water temperatures drop below 20°C for 2 months (mid-December to mid-February) and tilapia does not grow. A tilapia hatchery is required to produce mono-sex fry, but mixed-sex culture can be managed to supply fry for the next culture cycle and excess fry may be a source of fish to provide protein to supplement local feed. On the basis of a series of experiments conducted at the Institute of Agriculture and Animal Science (IAAS), Chitwan, Nepal, a model of a cage-pond integration system for mixed-sex tilapia culture has been developed. This system produces 250-300 g of harvest-size fish from 100-150 g fingerlings stocked in cages with feeding, and about 100-150 g harvest-size fish from stocking 20-30 g fingerlings in ponds without feeding, during one culture cycle of 5 months. Cage culture is for grow-out, whereas pond culture is for producing fingerlings for cage stocking as well as for grow-out. The model has two culture cycles in a year with a net yield of 3.5-4.0 t ha-1 cycle-1. The system produces new recruits for restocking in ponds. Excess recruits are used as feed with the small fish produced in the system supplying about 5% of the feed ingredients. This model yields 7-8 t ha-1 yr-1 in the subtropical climate of Nepal, which is three times higher than the average farmed fish productivity of the country.
Livelihood development through aquaculture for women-headed households in Noakhali char, Bangladesh.
Authors: Mowhila Reshad
Published: April 2021

Since 2003, the Greater Noakhali Aquaculture Extension Project (GNAEP) has started to switch its attention towards the hardcore poor, leading to a major concentration on the char lands (land newly emerged from rivers) of southern Noakhali, Bangladesh. Here at least 16% of households in the char area settlement villages are headed by women. GNAEP has identified a range of activities/options to support these households and has initiated a pilot programme called MOWHILA (Making Opportunities for Women-headed Households for Improving their Livelihood through Aquaculture), the main activities of which centre on household resource mobilization. The entire programme has been implemented through a participatory approach, involving consultation with different stakeholders based on the needs of the target beneficiaries. Early results of the pilot intervention in livelihood development through small-scale aquaculture suggest that such an approach can be effective in addressing the issues that confront poor women.
Icefish seed production and stock enhancement in lakes and reservoirs in China.
Authors: Wang Wei-min
Published: April 2021

Icefish are a group of small-sized and transparent or translucent fish species with a long slender shape. Their life cycle is characterized by an early onset of maturity, short life span and high reproductivity. They have a high price in both Chinese domestic and international markets. Icefish artificial breeding is limited to China although they are naturally found in other countries including Japan, Korea, Vietnam and Russia. Pond culture of the fish has yet to succeed. The fish is in short supply and the demand is high in both domestic and international markets. Production relies mainly on fisheries in lakes and reservoirs through stock enhancement by artificial release of fertilized eggs. The recommended releasing rate is a minimum of 100 eggs and a maximum of 500 eggs ha-1. Usually several years after a single release of fertilized eggs into a lake or a reservoir, a large population of icefish can be expected through self recruitment. Harvest can be carried out every year given favourable water conditions for reproduction and growth. Overfishing should be avoided and 20% of biomass should be kept in the water as broodstock to generate the next crop. In China about 10% of artificially established icefish populations are able to support commercial fisheries.
Impact of aquaculture extension and training on livelihoods of the poor in Bangladesh - FTEP-II.
Authors: Brown David
Published: April 2021

This case study describes an application of the sustainable livelihoods model as used by the Department for International Development, DFID, to a fisheries and aquaculture extension project in Bangladesh. Use of the livelihoods framework provided advisers, managers and national counterparts with a better understanding of the complexity of the poverty of the primary beneficiaries of the project (principally poor fish farmers and their families) and how the project interventions impacted their lives. Project impacts in terms of poverty targeting (impact on livelihoods assets), livelihoods strategies, policies institutions and processes and access and influence are described. Key issues in relation to the provision of extension services are presented.