Water Management in Penaeus monodon Farms in Khulna, Bangladesh: Some Case Studies

Abstract

There are many hindrances to good production from shrimp culture. Lack of proper water management in the culture farms is one of the principal ones in the greater Khulna areas. Problems of water quality management arise from the uneven pond bottom, heterogeneous pond depths, inappropriate tidal flux at the mouth of the sluice gates, lack of proper supply of water, lack of opportunity for water exchange within a suitable duration, and social conflict among the stakeholder farmers of a specific farming community in an area. The study was conducted in three areas of Khulna district, namely Paikgacha, Dumuria, and Dacope Upazillas. The rivers Shalta, Teligati, and Shibsa flow beside the three study areas of Kapilmuni in Paikgacha, Shobna in Dumuria, and Tildanga in Dacope, respectively. The Nasirpur Khal, Katakhali Khal, and Kakrabunia Khal were the main khals from where water was supplied to the respective areas. Data were collected through several visits to the areas. Individual interviews of the farmers, Focus Group Discussions with farmers, and Key Informant interviews were performed for the purpose. Interviews with a total of 90 farmers, 3 FGDs, and 30 Key Informants were conducted in the study. The total numbers of farms were 1,504, 304, and 99, and the total numbers of farmers were 1,524, 350, and 468 in the three areas, respectively. In two study areas, the main khals that supplied water to the farms were leased to other parties. They erected structures such as patta and nets in the canals, creating hindrances to water flow. This seriously reduced the water level at the far end of the khal. Heavy siltation in the khals raised the bottom of the khals. The farms lying at a far distance could not take in or remove water from their farms. There were no separate inlet and outlet canals in the farms. Therefore, there were no water exchange facilities except for farms adjacent to the khal. The depth range of the farms was 0.5 to 5 ft. There were some poultry farms beside the khal and many hanging latrines over the khal. These sources of waste polluted the water of the khal. There were associations of farmers in Paikgacha and Dacope areas, but they were not active. Shrimp farms were established without proper planning. To mitigate the problems, the main khals supplying water to the farms have to be kept free from lease. The sub-canals also have to be widened and kept free for the passage of water to the distant farms. In the absence of separate inlet and outlet canals, good water management would largely depend on cooperation among the farming community, and the existence of an active association is a must.