[Effect of ditching for drain on control of Oncomelania hupensis snail in beaches of Dongting Lake].

OBJECTIVE

To evaluate the effect of ditching for drain on the control of the breed of Oncomelania hupensis snails in beaches of Dongting Lake.

METHODS

From November, 2009 to November, 2012, an 0. hupensis snail infested beach of the Yueyang jail and an O. hupensis snail infested beach of Junshan District were selected as research fields in the eastern Dongting Lake area, and the former, as the intervention field, was performed with the ditching for drain by excavators and the latter, as the control field, was not.

RESULTS

Before the project implemented, the average soil moisture contents on the beaches in dry seasons of the two fields were both about 35.56%. After the project implemented, in the intervention field, the average soil moisture content was 26.53% which was significantly lower than that (35.56%) in the control field (F = 6.53, P < 0.05). The underground water levels in different heights in the intervention field were lower than those in the control field (χ2 = 33.33, P < 0.05). Before the project implemented, the natural death rates of the snails were 0.98% and 0.89% in the two research fields respectively (P > 0.05), and after the project implemented (in 2012), no adult and young snails were found in the interventional field, but in the control field, the average densities of living snails and young snails were 29.37 snails/0.1 m2 and 213 ± 108.45 snails/0.1 m2 respectively.

CONCLUSION

The intervention of ditching for drain can decrease the soil moisture contents quickly and change the ecological condition, therefore, can control the breed of O. hupensis snails in the beaches of Dongting Lake.