~ 42 ~ International Journal of Fisheries and Aquatic Studies 2017; 5(2): 42-49 E-ISSN: 2347-5129 P-ISSN: 2394-0506 (ICV-Poland) Impact Value: 5.62 (GIF) Impact Factor: 0.549 IJFAS 2017; 5(2): 42-49 © 2017 IJFAS www.fisheriesjournal.com Received: 10-01-2017 Accepted: 11-02-2017 Md. Motiur Rahman Scientific Officer, Bangladesh Fisheries Research Institute, Shrimp Research Station, Bagerhat-9300, Bangladesh Md. Ariful Islam Scientific Officer, Bangladesh Fisheries Research Institute, Shrimp Research Station, Bagerhat-9300, Bangladesh Md. Amirul Islam Senior Scientific Officer, Bangladesh Fisheries Research Institute, Shrimp Research Station, Bagerhat-9300, Bangladesh Syed Ariful Haque Lecturer, Dept. of Fisheries Technology, Sheikh Fozilatunnesa Mujib Fisheries University, Melandah, Jamalpur, Bangladesh Dr. Khan Kamal Uddin Ahmed Chief Scientific Officer, Bangladesh Fisheries Research Institute, Shrimp Research Station, Bagerhat-9300, Bangladesh Correspondence Md. Ariful Islam Scientific Officer, Bangladesh Fisheries Research Institute, Shrimp Research Station, Bagerhat-9300, Bangladesh Investigation of semi-intensive culture system of shrimp with special reference to soil-water characteristics of Bangladesh Md Motiur Rahman, Md Ariful Islam, Md Amirul Islam, Syed Ariful Haque, and Dr. Khan Kamal Uddin Ahmed Abstract The study was carried out to investigate the soil-water quality and production parameters of 9 selected semi-intensive shrimp ghers in Bagerhat and Khulna districts of Bangladesh over a growing cycle. Physico-chemical parameters of soil-water were measured and analyzed by standard methods. Gross yield (14998.05 kg /ha/cycle) of shrimp was also calculated from the stocking and harvesting data. Most of the parameters of soil and water correlated significantly with each other suggesting a high degree of interactions between different parameters in the system. A pattern of qualitative and qantative difference of zooplankton over phytoplankton was recorded in the semi-intensive farms Therefore, a high degree of salinity fluctuation and iron deposition in waters was also documented. However, significantly lower concentrations of phosphorus in the soil indicated a net retention and trapping of phosphatic nutrients in the environment. After that cropping pattern was two cycles per year, Feeding frequencies was four times in a day and Penaeus monodon production ranged from 4275 to 9645.66 kg /ha/ cycle in semi-intensive farms. The present findings indicate that semi-intensive systems served as less health risk in shrimp production and heavy usage of the surrounding water. Keywords: Water and Soil quality, Semi-intensive, Shrimp, Ghers, Bangladesh 1. Introduction Shrimp aquaculture is one of the fastest growing economic activities in coastal areas of Bangladesh. Bangladesh is the 5 th largest shrimp producer in the world [11] . In Bangladesh annual shrimp production is 223582 metric ton and 2 nd largest of total inland aquaculture [10] . The two main Region of shrimp production are located in the Southwestern part composed of Khulna, Satkhira and Bagerhat districts; and the other one is located in the Southeastern part of the country composed of Chittagong and Cox’s bazaar districts and 0.276 million hectares of land are currently under brackishwater shrimp cultivation [16] . About 75% of the total shrimp farms are located in Khulna, Bagerhat and Satkhira districts. Penaeus monodon and Macrobrachium rosenbergii are the two major species cultured in Bangladesh [24] . Shrimp farming in Bangladesh has been expanding since the early seventies and reached an industrial scale followed by increasing demand for shrimp in the export market. It alone contributes more than 70% of the total export earnings from all the agro-based products. More than two millions of people directly and indirectly are engaged in shrimp aquaculture activities (Harvesting, Culture, Processing, and Experting) [3] . Rapid expansion of shrimp farming in Bangladesh for the last two decades is likely to lead both short and long-term negative environmental impacts leading ecological imbalance, environmental pollution, acceleration of land degradation, low salinity deforestation of mangrove, sedimentation and disease outbreak [22] . Mangrove is unique ecosystem and suitable habitat for shrimp culture [15] . However, mangrove wetlands are still being converted to gher for shrimp aquaculture [25] . Shrimp culture in Bangladesh relies on the supply of artificially formulated feed application of agrochemicals, antibiotics and disinfectants [22] . Shrimp farmers apply different types of chemicals and drugs for remediation of shrimp death in their farms (locally called gher in Bengali) from various diseases.