Freshwater mollusks at designated areas in eleven provinces of Thailand according to the water resource development projects.

The study was conducted at 75 collecting loci in 15 districts of 11 provinces in Thailand during 1999-2004. A total of 12,079 live mollusks were collected, 11,874 were snails and 205 were clams. The snails were comprised of 39 species and classified into 9 families: Ampullariidae, Bithyniidae, Buccinidae, Potamiopsidae, Stenothyridae, Thiaridae, Viviparidae, Planorbidae and Lymnaeidae. The clams were comprised of 14 species classified into 2 families: Amblemidae and Corbiculidae. Fifteen species were medically important snails: Pomacea canaliculata, Pila ampullacea, P. pesmei, P. polita, Bithynia (Digoniostoma) funiculata, B. (D.) siamensis goniomphalos, B. (D.) s. siamensis, Filopaludina (Siamopaludina) martensi martensi, F. (Filopaludina) sumatrensis polygramma, Melanoides tuberculata, Tarebia granifera, Helicorbis umbilicalis, Gyraulus convexiusculus, Indoplanorbis exustus and Radix rubiginosa. Of these 3 snail species harbored trematode cercariae. I. exustus harbored Echinostoma malayanum, Xiphidio and Schistosoma spindale, and R. rubiginosa and B. (D.) siamensis goniomphalos harbored Xiphidio and intestinal flukes, respectively.

Preliminary post-tsunami water quality survey in Phang-Nga province, southern Thailand.

This preliminary water quality survey was performed eight weeks after the tsunami hit Phang-Nga Province on 26 December 2004. Water samples collected from the affected area, 10 km parallel to the seaside, were compared with water samples from the control area approximately 4 km from the seaside, which the tsunami waves could not reach. These samples included 18 surface-water samples, 37 well-water samples, and 8 drinking-water samples, which were examined for microbiology and physical-chemical properties. The microbiological examinations focused on enteric bacteria, which were isolated by culture method, while physical-chemical properties comprised on-site testing for pH, salinity, dissolved oxygen (DO), conductivity and total dissolved solids (TDS) by portable electrochemical meter (Sens Ion 156). The results of the microbiological examinations showed that water samples in the affected areas were more contaminated with enteric bacteria than the control area: 45.4% of surface-water samples in the affected area, and 40.0% in the control; 19.0% of well-water samples in the affected area, and 7.7% in the control. All eight drinking-water samples were clear of enteric bacteria. Tests for physical-chemical properties showed that the salinity, pH, conductivity, and TDS of surface-water samples from the affected area were significantly higher than the control. The salinity, conductivity, and TDS of the well-water samples from the affected areas were also significantly greater than those from the control area. The surface and well water in the tsunami-affected area have been changed greatly and need improvement.