bluuebunny/crossref_metadata_2025_split huggingface dataset:
Social development and human rights - child labour in aquatic products production and processing.
Authors: Monir  
Published: April 2021

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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).