Bacteria of sanitary significance in brackish water aquaculture farms and shrimps

Abstract

Microbial parameters viz., Escherichia coli, coliforms, vibrios and sulphate reducing clostridia of brackish water aquaculture farms and shrimps along with physio-chemical parameters have been investigated. The study covers the brackish watr farms of Ernakulam District (Kerala, India). There were visible variations in the pH, dissolved oxygen, salinity and light penetration in the farm water. Total bacterial count of water, sediment, and the sample of shrimps varied among different farms. Total plate count (TPC) for shrimp was highest followed by sediment and water. Counts for vibrios, coliforms, E.coli, and sulphite reducing clostridia (MPN) in sediment samples also showed the same trend. Counts for vibrios, coliforms, E.coli, and sulphite reducing clostridia in prawn samples were higher than in the water and sediment samples. There was a seasonal variation in the bacterial counts as TPC, E.coli and total coliform counts were higher during monsoon season while the vibrio count was higher during the post-monsoon season. Salinity was maximum during pre-monsoon, whwreas it was less during monsoon period. Dissolved oxygen was 8mg during monsoon period, whereas it was less during pre-monsoon and post-monsoon period.