| 摘要: |
| 根据2002 年6月对小清河口及毗邻海域进行的一次大面调查资料, 对叶绿素a、营养盐、溶解氧、化学耗氧量等环境因子的空间分布特征进行了研究, 分析了各环境参数之间的相关性。结果表明,研究区域没有明显的层化现象, 各参数的垂直分布都比较均匀。各环境参数在河口内外的分布情况具有显著差异。河口内为高温、低盐、高营养盐、低溶解氧、高化学耗氧量和高叶绿素a, 河口外则与此相反。在河口外, 硝酸盐由于受到黄河水输入的影响而比河口内浓度更高, 这使得河口外磷限制情况加剧而硅限制情况减轻。除亚硝酸盐外, 各参数均表现出良好的相关性。河口内丰富的营养盐使得浮游藻类过度繁殖, 水体叶绿素a含量平均达到8.0 mg/m3, 而河口外叶绿素a含量只有1.5 mg/m3。溶解氧在河口外海域平均值为3.5 mg/L, 而在河口内却低于2.0 mg/L, 处于低氧状态, 河口内最上游的站位表层达到了无氧状态, 是营养盐和有机物的双重污染促使了这种情况的发生。 |
| 关键词: 小清河口 叶绿素a 溶解氧 营养盐 缺氧 |
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| 基金项目:国家水体污染控制与治理科技重大专项项目(2008ZX07526-003); 山东省自然科学基金项目(Y2008E06) |
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| Chlorophyll a and other environmental parameters in the Xiaoqing River Estuary, Laizhou Bay: spatial distributions and statistical analysis |
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| Abstract: |
| Based on the observations from Jun. 6 to 7, 2002 in the Xiaoqing River Estuary, Laizhou Bay, Bohai, the spatial distributions and statistical correlations of chlorophyll a (Chl-a) and other environmental parameters, such as nutrient, dissolved oxygen (DO), chemical oxygen demand (COD), were analyzed. Regression analysis of Chl-a with DO and nutrients was performed to better understand their relationships. The research area is quite shallow, the water body is mixed equably, and there is no obvious stratification. So all parameters were well distributed vertically; however, the horizontal distributions of each parameter within and out of the estuary were significantly different. The levels of temperature, nutrients (except nitrate and nitrite), COD and Chl-a were relatively higher within the Xiaoqing River Estuary, whereas salinity and DO were lower. The nitrate out of the estuary was more abundant than that within the estuary because of the input of the Yellow River, and it intensified the phosphorous limitation and reduced the silicate limitation out of the estuary. Except nitrite, all parameters showed good correlations with each other. There were negative correlations between Chl-a and DO or nitrate, and positive correlations between Chl-a and phosphorous, silicate or ammonia. Regression analysis showed that the relationships between Chl-a and DO and ammonia were concentration-dependent. When the DO was higher than 3mg/L or the ammonia was higher than 25μmol/L the Chl-a had a square parabolic correlation with either of them, and there was no obvious relationship found when the DO and ammonia were at lower concentrations. The phytoplankton multiplied excessively because of high nutrient levels in the estuary, and the mean Chl-a content in the water was up to 8mg/m3. However, the mean Chl-a out of he estuary was only 1.5 mg/m3 because of the phosphorous limitation. The mean value of DO out of the estuary was 3.5mg/L, but within the estuary it was lower than 2mg/L (there was no DO at the surface layer of most upriver station). Hypoxia happened within the estuary, which was triggered by the co-pollution of nutrients and organic pollutants. |
| Key words: Xiaoqing River Estuary chlorophyll a dissolved oxygen nutrient hypoxia |
