Characteristics of Waters and Sediments and Effect of Ions on Odonate Nymph Haemolymph in Ban Pu Coal Mine Reservoirs, Lamphun Province, Thailand

Abstract

The study of the influence of acid mine drainage to living organism was conducted in November 2008 - August 2009. The study of odonate species were selected and collected the diversity data in coal mine reservoir as BP1G, BP1B and BP2 compared with the reference site as JL. The physico-chemical properties, ion concentrations in water and heavy metal concentrations in water and sediment were sampled every 2 month. The physio-chemical properties of water from Ban pu coal mine reservoirs and JL reservoir were compared with the standard of surface water quality of Thailand and Industrial Effluent Standard in Thailand. The result showed that, majority of water was moderate base on measured parameters. It was suitable for people to consume and for industrial purposed under sanitary controlled process and to conserve of aquatic animals and agriculture. Water qualities in JL showed a better quality than Ban pu coal mine reservoirs.

The study of odonate diversity found a total of 29 species 23 genera of odonate. The species recorded comprised of 9 Zygoptera species belonging to 7 genus in 4 families and 20 Anisoptera species belonging to 16 genus in 4 families. Shanon - Wiener diversity index (H') was taken account of species richness as well as abundance of odonate. H' was found in ranged of 1.5 - 4.5 and the highest value was found at JL while the lowest value was found at BP1B. As 4 study sites, JL and BP2 were the suitable habitat more than BP1G and BP1B. Due to JL and BP2 were found the periphytic plants around the edge of the study site which odonate preferred to live more than BP1G and BP1B. The concentrations of heavy metals in the water and sediment from the study sites were determined. The highest concentration of heavy metals was Mn at BP2 (24.0 mg/L) which was excessive when compared to the Industrial Effluent Standard of Thailand (5 mg/L). Therefore acid mine drainage impacts to the area through acidity, ferric ion precipitation, oxygen depletion, and release of heavy metals associated with coal and metal mining. All heavy metals were reported in the sediment from every study site, except Cu at the BP2 site. The samples taken from the BP1B, BP1G and BP2 sites showed higher concentrations in the sediment than those observed at JL. The concentration levels of Cu, Fe and Zn were found significantly different between all study sites, while As, Cd and Mn were found in lower concentrations. The ion composition levels in the water found Cl-, NO3-, SO42-, Na+, K+, Ca2+ and Mg2+. The study sites in the mining area (BP1B, BP1G and BP2) found that the ion concentration levels mostly followed in the same trend, while JL, the reference site, was different. Sulfate and Calcium concentrations as the predominant ion were always found from the BP1B, BP1G and BP2 sites. Sulfate is considered the best indicator of acid mine which the result from the oxidation of pyrite. The correlations between ion concentrations in haemolymph and water were found from each study sites. The correlation was significantly different in every study sites and ions which were found these correlations. The ion concentrations in water were lower than in haemolymph except SO42- which higher than the haemolymph. These results occurred from the acid mine drainage at the study sites which in the mining area. The exposure of odonate nymph to acidic water caused significant losses of Na+ and Cl- concentrations in haemolymph of Orthetrum sabina after 12 to 48 h of exposure time. This present study confirms previous result obtained in the experiment which clearly shown that the effect of low pH to Na+ and Cl- concentrations in haemolymph from many animals.