1.Key Laboratory of Mariculture & Stock Enhancement in North China’s Sea,Ministry of Agriculture, Dalian Ocean University, Dalian 116023, China；2.State Key Laboratory of Coastal and Shore Engineering, Dalian University of Technology, Dalian 116024,China
Abstract: Changes in temperature, salinity, pH value and dissolved oxygen saturation were monitored in culture ponds in coastal Bohai Sea and Huanghai Sea including coastal Wafangdian in Dalian, Dawa in Panjin and Donggang in Dandong in Liaoning Province from January to February in 2012. It was found that there was thicker ice depth in the ponds at Dawa in Panjin, 33.6 cm during initially iced period and 53.0 cm during heavily iced period. However, the thinner ice depth was observed in the ponds at Wafangdian, and Shashan in Dalian, 12.8 cm during initially iced period and 17.6 cm during heavily iced period. There was less water temperature fluctuation in the ponds at Dawa (-1.6 to -1.7 ℃), Panjin,at Donggang (-1.6 to -1.8 ℃), Dandong and at Beihai (-0.8 to -1.2 ℃), Wafangdian in Dalian during the initially iced period, except at Shashan (-0.8 to -1.4 ℃), Wafangdian in Dalian. There was a thermocline during heavily iced period, with variation in location and width. The lower salinity of 26.4-30.0 was found in the ponds at Donggang in Dandong, and higher salinity (33.5 to 34.9, fluctuation from 29.7 to 34.9) in the ponds at Dawa in Panjin during heavily iced period. The higher pH value was found to be between 8.6 and 8.5 in the pond at Dawa in Panjin, the minimum (7.2,and 7.5) at Donggang in Dandong. The dissolved oxygen in the seawater was almost saturated or supersaturated in all ponds during wintering period, and no hypoxia was occurred in the cultured animals. The variation in water temperature was shown to have an effect on the metabolism and survival of the sea cucumberApostichopusjaponicus, and the salinity fluctuation was also shown to have an effect on the survival of Manila clamRuditapesphilippinarum, at less water exchange and at optimal depth of 350-400 cm in a pond during in the large iced area.
2014, Vol. 29 
