Study of water quality of Bahmanshir River & water carrier canals and shrimp ponds (Litopenaeus vannamei) and their bacterial contamination in Choebdeh-Abadan region

Objective: One of the effective factors in management of shrimp farms is examination of bacterial water quality. Therefore in this survey the variations of total bacteria and total coliform has been examined. For this purpose within a cultured period, samples were taken from water of two stations in Bahmanshir River and two water carrier canals to shrimp ponds (C4 ,C5 ) and 6 active shrimp ponds that supply from canals. Method & Materials: Water of Bahmanshir river, two water carrier canals (C4&C5) and 6 shrimp ponds were sampled twice in month from May to end of culture period of shrimp (October) in 2007. Samples from each station were taken by sterile glassy bottle with robbery cap (next to ice) and sent to microbiology lab of South of Iran Aquaculture Research Center (SIARC), aseptically. Related tests including total viable bacterial count (pour plate method with 3 repetotion) and total coliform count (MPN method) were performed less than 6 hours after sampling. Furthermore physico-chemical parameters of water (salinity, temperature, pH, turbidity, No3, Po4) were carried out. Results & Conclusion: Results from samples analysis (Max & Min) trough out the sampling in Bahmanshir River demonstrated that variation process of total viable bacteria from 0.16×103 – 15.3×103 CFU/ml and in canals and ponds were 0.25×103 – 13.1×103 , 0.21×103 – 14.25×103 CFU/ml, respectively. Total coliform was variable from minimum value in pond and canals (3>CFU/ml) to maximum value in river >1100 CFU/ml). Results of Analyse variance (ANOVA ,minitab) with 95% safety level demonstrated that 2 stations of river and different months from this river had no significant difference in total bacterial count (p >0.05 ). But total bacterial count had significant differences between ebb and flow time in river (p<0.05). Total coliform of river in sampling months has significant differences (p=0.0003) but this difference has not been seen in canals and ponds. Correlation coefficient calculated between total bacteria and total coliform (positive correlation) and physico-chemical parameters. General results showed that the average of total bacteria and total coliform in ponds more than canals.

Keywords:

Bahmanshir , water , Litopenaeus vannamei , total bacteria , coliform , Choebdeh-Abadan