WATER QUALITY AND MANAGEMENT OF SHRIMP CULTURE IN SOUTHWEST COASTAL AREAS OF BANGLADESH

Abstract

The shrimp industry of Bangladesh is facing severe problems and results less production. A study was conducted under a DFID-funded research project (TROPECA) to investigate the issue during 2004. The study was done in an aquatic system of Dumuria Upazila of Khulna district comprising a river (semi diurnal tidal system), a canal and 10 shrimp ponds. Shrimp culture practices within the study area were mostly extensive to improved extensive system. Shrimp were being produced without proper pond preparation, water management, fry nursing, and feed management due to a lack of technical knowledge. There were also concerns about the risks associated with the consequence of higher levels of financial investment. Consequently, production rates were low, averaging only 191 kg ha-1 in the system. Entrance of untreated river water in the pond having less depth (<0.5 m) was considered as a major cause of shrimp mortality. The studied water qualities were within an acceptable range for shrimp during grow-out period except NH3-N and total nitrogen, which were exceptionally high throughout the aquatic system. River water, used as input water of shrimp farm, itself contained high level of NH3-N and dominated the water quality of the system. Therefore, a sustainable use of river water with measures to control the NH3-N should be encouraged where farm should be prepared with adequate depth (2.5-3.5 ft) and provided with adequate fertilizer and feed in order to minimize the shrimp mortality in this region.