| Author | Chowdhury, Md. Arif |
| Call Number | AIT DISS. no. AQ-06-05 |
| Subject(s) | Shrimp culture--Bangladesh
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| Note | A dissertation submitted in partial fulfillment of the requirement for the degree of Doctor of Technical Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | Shrimp farming is now established as an important aquaculture industry in many developing Asian countries. It is one of the best options for development in coastal areas with saline soils and provides well-paid employment for small holder households. Considering the profitability and high international market demand for shrimp product farmers and entrepreneurs attempted towards unplanned development of shrimp farming, while it is posing a challenge to the coastal sustainability as well as shrimp farming itself. The study analyzed the contexts of sustainability and identified the appropriate sustainable factors or indicators in relation to the coastal shrimp farming. In addition, the study examined these sustainability indicators quantitatively with regards to how they can be used through a unifying index that allows the present shrimp aquaculture to be assessed considering all sustainability components, such as environmental, economic and sociocultural factors separately and in interactions with each other. In the first part of the study a conceptual framework was developed for assessing the sustainability of coastal shrimp farming. The available literatures, documents related to shrimp farming and practical field experiences were used to develop the framework. As sustainability of shrimp farming is a time and space-specific concept and its assessment should be closely linked with specific farming systems and area where culture is taking place. The assessment process has identified current problem to develop acceptable indicators spatially and temporally and how to integrate them to address the performance of particular farming systems. The study has identified the sustainability factors influencing the performance of shrimp farming systems that are socially, economically and environmental conducive to costal development in general and shrimp farming in particular. Though the sustainability assessment is a difficult task, particularly its quantitative evaluation, several numerical formulae were established by considering all possible relevant factors and proposed various indicators such as shrimp farm effluent and soil quality, shrimp production stability, employment and equity, farmers' knowledge and acceptability of shrimp farming etc. These are related to determining the performance of shrimp farming. In the second part of the study the framework and indicators were tested in view to whether or not they address the important issues of the shrimp farming practices in coastal region. In view to fulfill the objectives the research was conducted in the three sub-districts (upozilas) in southwestern coastal Bangladesh where 75% of shrimp farms of the country are situated in this region. Two types of farming systems viz. shrimp-rice farming (80% of total farms) and year round only-shrimp farming (20% of total farms) following the traditional methods were studied in southwestern region of Bangladesh. Shrimp was the principal crop in both farming systems, however, finfish were stocked in both systems and rice was the secondary crop in only shrimp-rice system. The study incorporated household and farm survey and field experiments for assessing the performance of shrimp farming. A total of 150 households and farms (90 from shrimp-rice and 60 from only-shrimp farms) were surveyed by using questionnaire with shrimp farmers which included household condition, family income, farm production and its income, farmers perception (knowledge and attitudes) on shrimp farming and its environment etc. Twenty six soil samples (13 from only-shrimp, 8 from shrimp-rice, and 5 from only-rice) were collected by following the same plots were being used soil samples analysis by SRDI in 1990 to know changes in soil quality which is essential for environmental sustainability. Sixteen water samples (7 from only-shrimp, 5 from shrimp-rice and another 4 from nearby canal) were collected to compare the standard suitability ranges of extensive shrimp farm provided by many journals and reports. On the basis of economic return and risk, the shrimp-rice system was found better than that of only-shrimp farming though yield of shrimp in only-shrimp system was higher than that of shrimp-rice system but net profit was lower than shrimp-rice system as additional income comes from rice in shrimp-rice system. The soil fertility status in both systems was found good and there were no significance differences among the systems. Electric conductivity (EC) of soil was found with increasing trend in both systems due to intrusion of saline water and saline water holding for prolonged period in shrimp ponds. In terms of water quality no significant difference was found in both systems and between nearby canal system as both systems used non-significant amount of inputs like feed and fertilizer and occurred minimum water exchange. Social acceptability was found much lower in both systems as rice production was decreasing day by day due to soil salinization. Finally three-dimensional assessment framework (environment, economic and social) and their indicators were identified and tested statistically their validity for comprehensive integrated assessment of two types of farming systems in coastal Bangladesh. Collected information and data from two farming systems were used to test the framework. The result of the sustainability status was presented into its triangulation form of sustainability. It reflected the environmental sustainability of both farming systems was more sustainable than social and economic sustainability. Most of the farmers were found less dependent on supplementary feed and fertilizer rather dependent on natural productivity of their farms. As a result no environmental impact from effluent was found in both systems. Shrimp-rice system was economically more viable as extra benefits came from rice production. Both systems were less sustainable in term of social sustainability as many social conflicts were very common in coastal shrimp farming area of Bangladesh. However, social interventions in the coastal areas have been gradually improving the situation. Performance of shrimprice system was found better than only-shrimp farming. Shrimp production was not hampered significantly by short-term rice production rather economic growth was more stable in the case of shrimp-rice system. The empirical evidence has shown that the framework is valid and well-fitted for assessing the sustainability of shrimp farming in coastal Bangladesh. However social indicators like farmers' knowledge, organizational and infrastructural support, equity; economic indicators like profitability and salinization of environmental issues have to given more priority in sustaining the shrimp farming activities. Application of this technique and continuous monitoring of time-specific issues are very essential to coastal shrimp farming where the shrimp farming industry is now a big challenge to sustainability and sustainable coastal development as a whole |
| Year | 2006 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Aquaculture and Aquatic Resources Management (AQ) |
| Chairperson(s) | Shivakoti, Ganesh P.; |
| Examination Committee(s) | Ikejima, Kou;Yi, Yang.;Somsak Boromthanarat;Seeland, Klaus Theo.; |
| Scholarship Donor(s) | Aga Khan Foundation, Switzerland;AIT Fellowship; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2006 |