鸭绿江口邻近海域夏季粒级叶绿素a分布及影响因素研究

于2016年8月在鸭绿江口邻近海域采集水样，讨论了鸭绿江口邻近海域夏季粒级Chl a含量的空间分布规律及环境影响因素。结果表明，调查海域总Chl a含量介于2.91~17.46 μg/L之间，平均含量为6.54±3.56 μg/L，表层Chl a含量高于底层。小型级（Micro）Chl a含量表、底层分布规律相近，高值区均位于河流入海口处；表层和底层微微型级（Pico）Chl a分布规律相近，含量值在河流入海口处由东北向西南逐渐降低。微型级（Nano）Chl a含量在表层高值区位于河流入海口处偏西方向，底层则呈现北低南高的分布趋势。Micro级Chl a为夏季鸭绿江口邻近海域总Chl a的主要贡献者，平均贡献率为55.10%；Pico级和Nano级Chl a平均贡献率为27.61%和17.29%。Chl a主成分分析结果表明:底层各粒级Chl a含量与各环境因子均呈显著正相关（p < 0.05）；表层各粒级Chl a含量与盐度、透明度呈显著负相关，与硝酸盐（NO₃-N）、亚硝酸盐（NO₂-N）、磷酸盐（PO₄-P）、DIN、氮磷比、悬浮物浓度等呈显著正相关（p < 0.05）；Micro级Chl a含量与营养盐因子相关性更显著。

Size-fractionated chlorophyll a and its relationship with environmental factors in adjacent water of the Yalu River estuary in summer

Samples of chlorophyll a were collected in adjacent water of Yalu River estuary in August 2016 to discuss the distribution of sized-fractionated chlorophyll a and its influencing factors.The results showed that the total chlorophyll a concentration ranged from 2.91 μg/L to 17.46 μg/L, with an average value of 6.54±3.56 μg/L.The concentration of chlorophyll a in surface layer was much higher than it in bottom.The horizontal distributions of concentration of Micro-sized chlorophyll a in surface and bottom layer showed analogous tendency in general, which value reached to peak at the estuary of the river.Furthermore, the pattern of concentration distributions horizontally of Pico-sized chlorophyll a in bottom layer was similar to surface layer, with a degree of content gradually decreasing from northeast to southwest.However, the high value zone of the Nano-sized chlorophyll a in surface is situated on the west of the river estuary, with a horizontal distribution of north high and south low at bottom.As primary contributor the average contribution rate of Micro-sized chlorophyll a was up to 51.10% followed by Pico-sized chlorophyll a (27.61%) and Nano-sized chlorophyll a (17.29%).The principal component analysis (PCA) between size-fractioned chlorophyll a and environmental factors indicated that the concentration of underlying size-fractionated chlorophyll a was positive related to all environmental factors (p < 0.05).Moreover, the salinity, transparency were negative connected with size-fractionated chlorophyll a, whereas the content of nitrate, nitrite, phosphate, dissolved inorganic nitrogen (DIN), suspended substance and ratios of dissolved inorganic nitrogen (DIN) to phosphate could positively affect the structure of superficial size-fractionated chlorophyll a (p < 0.05).The concentration of Micro-sized chlorophyll a showed extremely positive correlation with nutrients than Nano-sized and Pico-sized chlorophyll a.