Kaptai Lake is the largest man-made freshwater body in Bangladesh. Though created primarily for hydroelectric power generation, it contributes to produce significant quantity of freshwater fishes, navigation, flood control and agriculture. It is located in the Kaptai Upazila under Rangamati District of Chittagong Division. The lake was created as a result of building the Kaptai Dam on the Karnaphuli River, as part of the Karnaphuli Hydro-electric project. Kaptai lake is located at 22 30 00 N 92 13 00 E / 22.5000 N 92.2167 E. Kaptai Lake has 'H' shaped structure and two arms of this lake is joined near Shuvalong which is a part of Karnaphuli river."

A study was conducted at Hatiya and Nijhum Island, Noakhali in the mid coastal region of Bangladesh to identify feasibility of mud crab culture for a study period of six months from January 2010 to June 2010. Data were collected through questionnaire interviews, focus group discussions and cross check interviews and also pH meter and Refractometer were used to measure water pH and salinity. It has observed that, there were three canal systems in Hatiya Island, where saline water intrusion was evident 670 Ha. in Hatiya and vast inundated area with saline water was found in Nijhum Island. The average temperature of the last three years was approximately 26.100C and rainfall was almost 10.85mm. Average temperature was lower in December-February and higher in March-October. It was observed that natural feeds were available in this study area and there was existed a small potential marketing channel with 3-4 middlemen. Also there was a good transportation system both water and road way. So, present study revealed that the area is suitable for crab culture during April to October.