Relationship between natural extinction of Oncomelania hupensis snails and water chemical properties in Eastern Dongting Lake areas
10.16250/j.32.1374.2018040
- VernacularTitle:东洞庭湖区钉螺自然消亡与水体化学性质关系分析
- Author:
Yu YANG
1
;
Wen-Bin LI
2
;
Wan-Ting CHENG
1
;
Ya YANG
1
;
Shu-Rong DONG
1
;
Lin-Han LI
1
;
Jie JIANG
3
;
Ying-Jian WANG
1
;
Dong-Jian YANG
1
;
Bin CAI
3
;
Jia-Bian YOU
4
;
Feng JIANG
1
;
Qing-Wu JIANG
1
;
Yi-Biao ZHOU
1
Author Information
1. Key Laboratory of Public Health Safety, Ministry of Education, Tropical Disease Research Center, Department of Epidemiology, School of Public Health, Fudan University, Shanghai 200032, China
2. Junshan District Center for Disease Control and Prevention, Hunan Province, China
3. Station for Schistosomiasis Prevention of Junshan County, Hunan Province, China
4. Qianlianghu Station for Schistosomiasis Control, Hunan Province, China
- Publication Type:Journal Article
- Keywords:
Oncomelania snail;
Chemical contaminant;
Natural extinction;
Dongting Lake area
- From:
Chinese Journal of Schistosomiasis Control
2019;31(2):126-133
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the reasons of natural extinction of Oncomelania hupensis snails by comparing the difference of the water chemical properties between the snail-breeding marshland and non-snail marshland in Eastern Dongting Lake areas. Methods Three adjoining marshlands in Eastern Dongting Lake areas were selected, one was a snail-breeding marshland, the second was a non-snail marshland, and the third was a boundary zone between them. During the periods of water-rising season, wet season and water-falling season, the water samples from the bottom of 0.5 m were collected by the systematic random sampling method (200 m × 200 m grid method). In addition, the water samples below the surface of 0.5 m were also collected in the wet season. The physicochemical indexes of the sampling water were detected. Results According to the Surface Water Environmental Quality Standard (GB 3838–2002), the water quality indicators which were less than the detection limit were Cr, Cd, Zn, Hg, Cu, S－ and CN－ during the three sampling seasons. The pollutants which were slightly higher than Grade III but lower than Grade IV (Hg ≤ 1 μg/L, TP ≤ 0.1 mg/L) were Hg and TP. The pollutants below the Grade III included As and F－. The temperature and pH values were within the Grade III. The oxygen consumption indicators covering DO, COD and BOD in the water-rising season and wet season were within the Grade III, while the value of BOD was beyond the scope of Grade III but was between Grade Ⅳ (≤ 6 mg/L) and Grade V (≤ 10 mg/L) in the water-falling season. The differences of the water pollution indexes between the snail-breeding marshland and non-snail marshland were statistically significant, and these indexes included F－, As and pH in the water-rising season (P < 0.05); pH, BOD and Fat the surface layer in the wet season (P < 0.05); F－ at the bottom in the wet season (P < 0.05); TP and F－ in the water-falling season. Moreover, the above-mentioned indexes in the non-snail marshland of Qianliang Lake were higher than those in the snail-breeding marshland of Junshan Park. Thus, F－ was the only index which had statistical differences in every sampling season, and the concentration of F－ at the non-snail marshland was also higher than that at the snail-breeding marshland. In the water-rising season, the pH value at the non-snail marshland exceeded the suitable range for the growth of snails (6.8 to 7.8). Conclusion In the Eastern Dongting Lake area, the high concentration of F－ and pH of water may be responsible for the natural extinction of O. hupensis snails.
