莱州湾沿岸河流对邻近海域表层水体中Chl a浓度的影响

The impact of rivers on the Chl a concentrations in coastal surface waters of the Laizhou Bay

根据2012年9月底对莱州湾沿岸河流和邻近海域表层水体中Chl a和相关环境参数的调查,分析了Chl a在该区域的分布、影响因素、富营养化状况以及变化趋势。莱州湾沿岸河流Chl a浓度平均值为51.9μg/L,邻近海域为3.9μg/L。在沿岸河流,与Chl a呈显著正相关的仅有悬浮颗粒物(SPM),而在邻近海域,与Chl a呈显著正相关的有SPM、PO4-P、NH4-N、NO3-N。氮和磷都是莱州湾近岸海域Chl a的限制因子,其中氮的限制作用较大。莱州湾沿岸河流水体的富营养化程度主要表现为过度和高度富营养化,近岸海域水体的富营养化程度则主要表现为低度富营养化。沿岸河流高浓度的氮磷汇入,将会促进莱州湾近岸海域浮游植物生长,进而导致莱州湾近岸海域Chl a浓度增加并有可能使该区域的富营养化程度增加。

The distribution of Chl a concentration in riverine and coastal surface waters of the Laizhou Bay was investigated in September 2012. Related environmental parameters were also measured and their impact on the distribution of Chl a concentration was analyzed. The results showed that the average concentration of Chl a in the riverine and marine regions was 51. 9 and 3. 9 μg / L,respectively. In the riverine region of the Laizhou Bay,only suspended particulate matter（ SPM） had a significantly positive correlation with Chl a; while in the marine region,SPM,PO4-P,NH4-N and NO3-N had significantly positive correlations with Chl a. Both nitrogen（ N） and phosphorus（ P） were the limiting factors for the distribution of Chl a in the surface waters of the marine region,and N seemed to play a greater role than P. Surface waters in the riverine region were mainly in the status of serious and high eutrophication,and surface waters in the marine region were mainly in the status of low eutrophication. The rivers,the waters of which contain nutrients of high concentration,discharge considerable amounts of nutrients into the Laizhou Bay,making its coastal marine area more suitable for the growth of phytoplankton and then promoting the concentration of Chl a,and have the potential to aggravate the extent of eutrophication of this area.