海水越冬池塘冰下水体主要理化因子变化的初步研究

于2007年10月至2008年3月,对辽宁省盘锦、营口地区部分海参、贝类、种蟹越冬池塘的水温(T)、溶解氧(DO)、透明度(SD)、冰下照度、pH、总氨氮(TNH~+_4-N)、亚硝酸盐氮(NO~_-2-N)、硝酸盐氮(NO~_-3-N)、有效磷(PO_4-P)和化学耗氧量(COD)等进行了全面系统的调查,并对添加淡水对海水越冬池保温、增温效果进行了对比研究.结果表明:添加淡水对越冬池塘中、下层水有明显的保温增温作用,水温在3 ℃以上,而不添加淡水的池塘越冬期间水温为-1.6～3.7 ℃,最低温度出现在1月底至2月初,平均为-1.2 ℃;冰下照度呈现先降低后而升高的趋势,最低点出现在冬至前后,冬至当天9: 00左右的冰面照度为16.56 klx,全天光照大于1 klx的时间一般为6～7 h以上;透明度呈现先增加而后降低的趋势,最大为(1.24±0.25)m,最小为(0.68±0.13)m;DO一般较高,最大为(22.09±4.25)mg/L,最小为(7.81±5.42)mg/L;pH值则一般为8.5～9.0,最低为8.33±0.34,最高为9.27±0.27;COD含量为(8.18±1.47)mg/L,最低为(5.35±2.21)mg/L,最高为(10.80±1.46)mg/L;TNH~_+4-N含量为(0.358±0.260)mg/L,最低为(0.047±0.048)mg/L,最高为(0.785±0.162)mg/L;NO~_-3-N含量为(0.045±0.059)mg/L,最低为(0.002±0.002)mg/L,最高为(0.215±0.077)mg/L;NO~_-2-N含量为(0.017±0.016)mg/L,最低为(0.001±0.001)mg/L,最高为(0.055±0.051)mg/L; PO_4-P含量为(0.009±0.003)mg/L,最低为(0.003±0.002)mg/L,最高为(0.013±0.012)mg/L.研究表明,添加淡水对池塘DO、pH、COD以及营养盐的垂直分布有显著影响,但对透明度、冰下照度等影响不明显.

Changes in physical and chemical factors under ices in seawater ponds during a wintering period

Water temperature (T) ,dissolved oxygen (DO) ,transparency (SD) , light intensity, pH, ammonia-nitrogen(TNH~_+4-N), nitrite nitrogen(NO~_-2-N),nitrate nitrogen(NO~_-3-N), phosphate phosphor(PO_4-P)and chemical oxygen demand (COD) were determined under ices in some seawater ponds in Panjin and Yingkou, Liaoning province from Oct.2007 to Mar.2008. The water temperature was found to vary from -1.6 ℃ to 3.7 ℃, averaging -1.2 ℃, the minimum at late January or early February. The light intensity decreased first, and then increased. About 16.56 klx was observed on the Winter Solstice(09:00 a.m.),and the daily light density of over 1 klx was maintained over 6 or 7 hours during a wintering period. The transparency, however, increased first, and then decreased, the maximum (1.24±0.25)m and the minimum (0.68±0.13)m. Generally, the high dissolved oxygen levels were occurred, the maximum (22.09±4.25)mg/L, the minimum (7.81±5.42)mg/L. The pH was usually fluctuated between 8.5 and 9.0 with the lowest 8.33±0.34,and the highest 9.27±0.27. The maximum COD was (10.80±1.46) mg/Laverage (8.18±1.47)mg/L],TNH~_+4-N(0.785±0.162) mg/Laverage (0.358± 0.260)mg/L],NO~_-3-N(0.215±0.077) mg/Laverage (0.045±0.059)mg/L],NO~_-2-N (0.055±0.051)mg/L(0.017±0.016)mg/L] and PO_4-P (0.013±0.012)mg/L(0.009±0.003)mg/L] while the minimum COD was (5.35±2.21)mg/L, TNH~_+4-N (0.047±0.048)mg/L,NO~_-3-N (0.002±0.002)mg/L, NO~_-2-N (0.001±0.001)mg/L and PO_4-P (0.003±0.002)mg/L. The results showed that a fresh water layer on the surface was apparently devoted to the relatively high water temperature in the middle and the bottom water layers, and to affect the vertical distribution of DO, pH,COD contents and nutrients, but did not affect the transparency and light intensity under the ice.