Bacteriological Monitoring of Sea Water in Fish Cage Culture Farms on the Andaman Coast of Thailand

Abstract

The bacteriological monitoring of fish cage culture farms was carried out during the period from April 2007 to May 2008 in four provinces, Phangnga, Krabi, Trang and Satun along the coast of the Andaman Sea, southern Thailand. The water samples from the reference and cage stations were collected at bimonthly intervals. Total coliform bacteria (TC) and fecal coliform bacteria (FC) in water samples were analyzed by the standard method for the examination of water and wastewater. The TC and FC values were compared in the context of the Pollution Control Department (PCD) of Thailand guidelines for coastal water quality standards. The results showed that mean TC and FC values in most overlying water samples from the cage stations were higher than in samples from the reference stations at all study sites. A high degree of bacteriological pollution was observed at the reference and cage stations during some sampling periods at Ban Ba Gan, Krabi province, where the TC value was higher than the value recommended by the PCD standard. Maximum FC values in the examined water samples from the cage stations from some sampling periods at the study sites of Phang-nga, Krabi, Trang and Satun provinces were higher than the value recommended by the PCD standard. However, the means of TC and FC values at all study sites were lower than the value recommended by the PCD standard, except at the station at Ban Ba Gan, Krabi province. Effluent management of the sanitary sewer systems associated with rural settlements beside the river in this area should be implemented to reduce the risk from fecal bacterial contamination.