Decentralised fish seed networks in Northwest Bangladesh: impacts on rural livelihoods

Ricefield based fish seed production (RBFSP) in irrigated spring (boro) ricefields after initial introductions by external promoters has spread among farmers in parts of Northwest Bangladesh. This approach to producing juvenile fish, rather than by specialised geographically clustered hatchery and nursery enterprises, has been recognised as a strategy for decentralised production that makes large high quality seed available locally and supports food fish production. RBFSP has been promoted by the international NGO CARE as part of a process to improve rice-based livelihoods of farming households using a farmer field school (FFS) approach in two consecutive projects between 1993 and 2005. The approach is technically simple and is based on the stocking of common carp (Cyprinus carpio) eggs and Nile tilapia (Oreochromis niloticus) broodfish in ricefields. As a new approach to farmer level fish seed production, its livelihood impacts on the farming households as well as associated actors; its adoption, adaptation and rejection process in farming households; and its cost-effectives for dissemination at farmer level were not well understood. This thesis mainly applies the concept of the sustainable livelihood approach (SLA) using tools and processes of the growing family of participatory research. A systems approach was used to ensure that the key stakeholders including households, community and extension organizations were included. The study was initiated with a well-being analysis of community households to identify poorer households before exploring impacts of RBFSP on poorer producing households (RF) compared to non-producing (NRF) households based on one-off and longitudinal surveys. Livelihoods impacts on other actors linked directly and indirectly with RBFSP were also investigated. The adoption process of RBFSP at the household level and the cost-effectiveness of its promotion were assessed. Impact studies at the household level showed that RF households were significantly larger and had lower levels of formal education than NRF. Adoption of RBFSP had improved practical skills and hence substantially improved human capital in RF households. RF households tended to have more of their ricefish plots located adjacent to their households. Poor and intermediate adopters had smaller riceplots than better-off households but higher seed production efficiencies (poor-315.1 kg fingerlings/ha; intermediate-419.1 kg fingerlings/ha) than better-off households (294.6 kg fingerlings/ha). In addition to direct consumption of large fingerlings, RF households restocked them for further growth in their household ponds in doing so increasing yields by 60%. Fish consumption increased substantially in RF households based on their own production reducing their dependency on purchase from markets. The year round longitudinal survey revealed that activities for RBFSP were compatible with their existing rice-based agriculture activities for household members including men, women and children. The relatively limited income from fingerling production improved cash flow in the low income months. Consumption of large size fingerlings from ricefields provided nutrient dense food in the ‘hungry gap’ months when supplies of wild fish were poor, smoothing consumption. Apart from RF households, RBFSP extended its livelihoods impacts to a wide range of actors in and around the seed producing community. Poor fry traders were found to be key actors in the spread and support of RBFSP. On average fry traders supplied fingerlings to 35 foodfish producers within a mean distance of 5 Km from producing households in a community where RBFSP was well established. The end users (foodfish producers) included households with their own ponds, ponds with multiple ownership and larger waterbodies leased by small groups. Locally available RFBSP juveniles were attractive to each of these groups, supplementing hatchery derived seed. A large number of complex socio-cultural and technical factors were related to household level adoption of RBFSP. The major factors included use of cash generated to prevent distress sales of rice; lack of requirement to use pesticide in ricefields; meeting the household consumption demand; capacity to restock fingerlings in ponds; lack of any negative effects on rice production; increased non-stocked fish production in riceplots; simplicity of the technology; ease of fish harvest from riceplots; increased ability to gift fingerlings/foodfish to relatives and neighbours; more efficient use of both riceplot and irrigation pumps. The most important reasons for households not attempting or quickly rejecting RBFSP were labour conflicts with other activities. However, lost access to the riceplots through changes in tenure was the most common cause of late rejection by households who had practiced RBFSP for several years after withdrawal of CARE support. Location of fish seed producing plots close to the homesteads facilitated household women to contribute to seed production activities through feeding and looking after fish. Women were able to decide and control resources generated from fingerling sales as well as choosing to gift fingerlings to their relatives. Informal transfer of fingerlings in this way stimulated spread of RBFSP. Decentralised fish seed production was promoted through FFS very cost effectively. The introduction of an improved strain of Nile tilapia (GIFT) broodfish greatly enhanced the returns from decentralised seed production based on common carp alone. High levels of secondary adoption improved benefits from promoting RBFSP. The major benefit derived from the improved returns to food fish farmers using locally produced seed. Higher levels of net present value (NPV) and benefit cost ratio (BCR) were achieved based on promotion of mixed-sex tilapia in RBFSP than mono-sex tilapia produced in a large scale central hatchery. Cost-effectiveness in terms of multiplier development impacts on ramification of secondary adopters and, income of fry traders and foodfish producers, RBFSP also showed better performance than a mono-sex tilapia hatchery

Specific Growth Rate (SGR) in Different Stages of Tilapia (Oreochromis niloticus) Production Cycle in Cemented Tank Based Semi-Intensive Aquaculture System

Traditional assessment of specific growth rate (SGR) using the data of the beginning and the end of aquaculture production cycle, avoiding intermediary data, is criticized as misleading way by the scholars. However, by knowing SGR in different stages of fish growth, the utilization of feed by fish can be well known. The study was conducted with aim to assess SGR of Tilapia in six concrete tanks for 90 days from 8th May to 10th August, 2017. Tilapia (Oreochromis niloticus) fry was released at the rate of 4 fry per tank equivalent to the stocking density of 160 fishes/decimal as of the semi-intensive aquaculture system. Sinking and floating feeds were used for feeding the fish in T1 and T2, respectively with three replications for each treatment. During the experimental period, feed was given at the rate of 20%, 15% and 10% of the body weight in 1st, 2nd and 3rd month, respectively. Moreover, aeration facilities were installed for 24 hours using air stone aerator. The weight of fish was recorded using digital balance in 3 days interval to measure SGR. The water quality parameters i.e., temperature and dissolved oxygen (DO) were recorded twice daily. The weight gains of fish were 49.90±2.40 g and 63.12±4.97g for T1 and T2, respectively. The mean percent weight gain of Tilapia was higher in T2 (747±0.00 g) than T1 (253.51±0.00 g). Feed conversion ratio (FCR) in T1 and T2 were 1.70±0.07 and 1.90±0.20, respectively. Considering the data at the beginning and the end of the production cycle, the SGR (% per day) of Tilapia in T1 and T2 were 6.27±3.27 and 6.26±3.83, respectively. The SGR for floating feed was higher at the initial stage of production cycle and lower in the later stages. For sinking feed, SGR was almost static from the beginning to the end. The higher FCR in T2 correlated with the lower SGR in the later stage of the culture period. Higher total production was obtained in T2 (830.96 g) than T1 (610 g) with 100% survival in both treatments. Therefore, determining SGR in a specific interval, at least 15 days interval, might be the efficient feeding practice of Tilapia farmers.&nbsp

Growth performance of silver carp (Hypophthalmichthys molitrix) in cage stocked at different densities

An experiment was conducted to evaluate the growth performance of silver carp (Hypophthalmichthys molitrix) in cage stocking at different densities. It was expected that silver carp could grow feeding on plankton without external feeding. In this experiment, silver carps in nine cages were stocked in three different stocking densities such as 20, 30 and 40 fishes/m3 designated as treatments T1, T2 and T3, which were located in the south west corner of the L-shaped pond in Field Laboratory Complex, Faculty of Fisheries, Bangladesh Agricultural University (BAU), Mymensingh consisting of three treatments with three replications of each for a period of 90 days from 18th August to 17th November, 2015. Each cage size was 1m x 1m x1m (length x width x height) and silver carp was cultured in the cage with natural feed which filtered phytoplankton mainly. Twenty five genera of phytoplankton were identified in pond and the average phytoplankton production was around 8.44x105cells/liter. Water quality parameters such as temperature, dissolved oxygen, pH and transparency were recorded fortnightly. At the completion of the experiment, weight showed significant difference (p>0.05) among three treatments although length didn’t vary significantly. The highest length gain (18.61+0.369 cm) and the highest weight gain (62.52+2.249 g) were found in T1. The highest SGR% for silver carp was found in T1 and the highest total production was obtained in T3 (5.00+ 0.015 kg/m3). Individual growth performance of silver carp was satisfactory. Further studies are needed with different stocking densities and duration to verify the result

EMBRYONIC AND LARVAL DEVELOPMENT OF SILVER BARB (BARBODES GONIONOTUS) IN A MOBILE HATCHERY UNDER LABORATORY CONDITION

This investigation was carried out for 14 days to determine different developmental stages of embryo and larvae with special emphasis on time requirement for progress of the stages. For breeding of silver barb, PG was injected as an inducing agent for ovulation of eggs inside the ovary however, external stripping was applied to ejaculate the eggs. Sophisticated digital camera (Olympus C×41) connected with a laptop was used for intensive observation on the developmental stages in the close proximity of Low Cost Mobile Hatchery (LCMH). Well fertilized eggs were transformed into fry through different stages of embryonic development, hatchlings to larvae and then fry completing several morphological and physiological changes. The size of fertilized and unfertilized eggs was 0.8±0.05 and 0.7±0.05 mm, respectively. Initial 4 stages from fertilized egg to blastula was quicker being completed within 5 hrs compared to following 4 stages from gastrula to hatchling that took 9 hrs. This indicates quality hatchlings production within a limited time having an importance in hatchery management system. During the larval development stages, yolk sac was absorbed within 72 hrs indicating proper time of first external feeding. The alimentary canal and conversion of notochord to vertebra through segmentation occurred within 144 and 192 hrs respectively. However, final development of pectoral, pelvic and, caudal and dorsal fins with rays, mouth and scale formation were completed within 336 hrs after hatchling stage

Shrimp value chains in Bangladesh: A scoping study of possible research interventions

Shrimp is Bangladesh’s main agricultural export and makes a substantial contribution to the economy of southern Bangladesh, but the sector has a checkered history. Bangladesh’s shrimp production and exports have been in steady decline, since peaking in the early 2010’s. Most shrimp exports from Bangladesh are used by the food service and niche ethnic markets in Europe. The complex nature of shrimp supply chains in Bangladesh, comprised of hundreds of thousands of small polyculture farms and tens of thousands of small traders, make it difficult to implement tracea bility and certification initiatives – now a prerequisite for entry into most supermarket supply chains. This report provides an overview of the sector and the challenges it faces, drawing on secondary and survey data, reviews of government reports and academic literature. We also report the findings of an expert consultation conducted to identify key constraints and potential solutions. The consensus among industry stakeholders who were part of the expert consultations is that issues related to the supply and quality of shrimp seed and pond management practices represent some of the most pressing, yet relatively simple-to-solve challenges currently faced by the sector. This would serve as the foundation for establishing traceability and certification processes. Previous interventions aimed at upgrading production practices (such as promoting stocking of disease-free shrimp seed) and facilitating disintermediation and transparency in the supply chain (such as by establishing producer groups, shrimp collection centers, and contracts with processors), have met with limited success. We outline potential interventions and partners that might offer scalable solutions enabling small shrimp farmers to access global markets

Comparative juvenile performance assessment of genetically improved Nile tilapia (Oreochromis niloticus L.) under commercial conditions in Bangladesh

Two on-farm juvenile performance trials were conducted at a hatchery in Bangladesh to compare a genetically improved strain of farmed Nile tilapia (GIFT) and a local strain (LS) produced by commercial operators. A 21-day early nursing trial was conducted in five replicate hapas followed by a 27-day advanced nursing trial in six replicate hapas. The mean feed conversion ratios (FCR), mean specific growth rates (SGR), mean individual final weights, mean production yields and mean survival rates were calculated for both strains. During the early nursing trial, GIFT fry survival rate and overall yield were significantly (p < 0.05) greater than LS values, which in contrast demonstrated better FCR and SGR. Improved performance was demonstrated in terms of FCR, SGR and yield for GIFT during the advanced nursing trial and mean final individual weights were 78% greater for GIFT than LS fish (2.26 g and 1.27 g respectively). Economic analysis indicated GIFT fish produced a net return 84% greater than that of LS fish at the end of the early nursing period, and by the end of the advanced nursing period, this difference had grown further such that GIFT generated a gross return over double that of LS. The results from a survey of tilapia grow-out farmers suggested producers from poor, medium and better-off backgrounds agreed GIFT performed better than traditional strains and is beneficial for aquaculture growth in Bangladesh. However, the results also indicate there may be a greater propensity for better-off farmers to appreciate the potential benefits of improved strains over poorer farmers

The Structure, Conduct, and Performance of the Midstream Segments of the Aquaculture Value Chain in Bangladesh

Abstract accepted for presentation at the Annual Meeting of the World Aquaculture Society held in Singapore on 29 November to 2 December 2022. The presentation discussed the comprehensive statistically representative study of 329 aquatic product traders in 31 markets from seven districts in south and southwest Bangladesh between January and May 2021to look into the organization and behavior of actors in these segments of the aquaculture value chain in Bangladesh

The Structure, Conduct, and Performance of the Midstream Segments of the Aquaculture Value Chain in Bangladesh

The presentation talked about the comprehensive statistically representative study of 329 aquatic product traders in 31 markets from seven districts in south and southwest Bangladesh between January and May 2021to look into the organization and behavior of actors in these segments of the aquaculture value chain in Bangladesh

Harnessing Machine Learning to Estimate Aquaculture’s Contributions to the Economy of Southwest Bangladesh

Abstract accepted for presentation at the Annual Meeting of the World Aquaculture Society held in Singapore on 29 November to 2 December 2022. The presentation detailed the use of machine learning techniques to extract information from freely available satellite images and estimate the area of waterbodies used for aquaculture in seven districts in southern Bangladesh, one of country’s most important aquaculture zones producing fish for domestic markets and crustaceans for export

Harnessing Machine Learning to Estimate Aquaculture’s Contributions to The Economy of Southwest Bangladesh

The presentation detailed the use of machine learning techniques to extract information from freely available satellite images and estimate the area of waterbodies used for aquaculture in seven districts in southern Bangladesh, one of country’s most important aquaculture zones producing fish for domestic markets and crustaceans for export. The research combined machine learning derived estimates of aquaculture farm area per district with data from statistically representative farm surveys to estimate farm size, productivity, and total output, economic value of production, on-farm employment generation by gender, and demand for formulated and non-formulated feeds