冬季海水养殖水域环境因子的变化对养殖海参的影响

Influence of Environmental Elements Change of Marine Aquaculture Waters on Cultured Sea Cucumber in Winter

2016年和2017年两个结冰期内对渤海某海水人工养殖池塘冰厚度的变化和冰盖下水体的温度、盐度、p H和溶解氧进行连续观测。冰厚采用超声测距仪定时测量,冰温、水温、盐度、溶解氧和p H分层观测。研究发现,盐度的变化与冰的生长密切相关,而冰厚度的变化主要受气温的控制,p H和溶解氧的变化与水温和光合作用相关,冰融化时p H和溶解氧变化浮动较大,冰融水起到了稀释作用,溶解氧浓度降低。可见,气温影响冰厚和水温,进而间接影响了盐度、p H和溶解氧。观测的养殖池塘水体溶氧含量一直大于8 mg·L-1,没有出现缺氧的情况。p H范围在7. 7～9. 0之间,没有出现异常。养殖池塘内的海参对盐度的耐受范围是20～35,而其栖息的水体底层的盐度,主要是在29. 022 7～34. 028 6间,仅当冰融化时,盐度最低值降到21. 074 8,但在之后再3～5 d内上升至29,可见,盐度的变化是在其可承受范围内。综上分析,温度是决定冬季海水养殖生物存活率的限制因素。

Ice thickness and temperature,salinity,p H and dissolve oxygen of water under ice were continuously observed in artificial mariculture ponds in the Bohai sea during two ice periods of 2016 and 2017. Ice thickness was measured by ultrasonic range finder at regular intervals. Ice temperature,water temperature,salinity,dissolved oxygen and p H were observed by layers. It is found that the change of salinity is closely related to the growth of ice,and the change of ice thickness is mainly controlled by temperature. The change of p H and dissolved oxygen is related to water temperature and photosynthesis. When the ice melting,the change of pH and dissolved oxygen fluctuates greatly,the dissolved oxygen concentration decreases by the dilute effect. Change of air temperature varies ice thickness and water temperature. Variation of water temperature alters water salinity,dissolve oxygen and p H. The anoxic zones never formed during ice cover period. Dissolved oxygen concentration is greater than 8 mg/L. The value of pH is 7. 7 ~ 9. 0,it is normal. The range of salinity is 29. 022 7 ~ 34. 028 6 during ice growth. The minimum of salinity on bottom water is 21. 074 8 when the ice melt,and then rises to 29 after 3 ~ 5 d. The sea cucumber lived on bottom of lake,its tolerant ranges of salinity are 20 ~ 35. The salinity change is within its acceptable range. So the change of water temperature is key factor determining the survival rate of mariculture organisms in winter.