PHYTOPLANKTON HABITATS RESPONSE TO THE VARIABILITY OF ESTUARINE HYDRODYNAMIC CONDITION IN THE MACROTIDAL CHIKUGO RIVER ESTUARY
PHYTOPLANKTON HABITATS RESPONSE TO THE VARIABILITY OF ESTUARINE HYDRODYNAMIC CONDITION IN THE MACROTIDAL CHIKUGO RIVER ESTUARY
复制标题
筑后江口大潮汐浮游植物生境对河口水动力条件变化的响应
DOI：
10.1142/9789811275449_0041
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Azhikodan Gubash
中科院分区：
文献类型：
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作者：
Nwe Lett Wai;Yokoyama Katsuhide;Azhikodan Gubash
在2021年的小潮-大潮周期中，研究了水动力和混合条件对潮汐主导的筑后河口浮游植物组成及其生境变化的影响。在小潮-春季过渡期间，河口从分层状态转变为混合状态。研究期间河流流量< 60 m3 s-1。小潮期间海水侵入17公里（上游），大潮期间侵入16公里。小潮时表层悬浮泥沙浓度（SSC）较低，大潮时最高（~ 400 mg/L），与混合作用的变化相对应，大潮时河口最大浑浊带（ETM）在8-12 km之间形成。海洋环境中的硅藻是主要的群体，占浮游植物总数的20-89%。在一个小潮-大潮周期中，淡水绿色藻类的最大丰度出现在小潮期间，而硅藻（包括海洋和淡水生境）出现在小潮后2 d，淡水蓝绿色藻类出现在中潮，以响应混合条件的变化。海水硅藻和淡水蓝绿色藻类的分布与盐度呈正相关，淡水绿色藻类和淡水硅藻的分布与盐度呈负相关。本研究的结论是，盐水入侵和混合条件驱动的潮汐强迫主要控制的物种组成和栖息地在筑后河口。
The effects of hydrodynamic and mixing conditions on the variation of phytoplankton composition and their habitats were investigated in the tide-dominated macrotidal Chikugo River estuary during a neap-spring tidal cycle in 2021. The estuary changed from stratified to well-mixed conditions during a neap-spring transition. The river discharge was < 60 m3s-1during the study period. Seawater intruded towards 17 km (upstream) during neap tide and until 16 km during spring tide. Surface suspended sediment concentration (SSC) was low during neap tide and maximum (∼400 mg/L) during spring tide corresponding with changes in mixing and an estuarine turbidity maximum (ETM) was developed between 8-12 km during spring tide. Marine habitats diatoms were the major group with 20-89% of total phytoplankton. During a neap-spring tidal cycle, the maximum abundance of freshwater green algae was found during neap tide while diatoms (both marine and freshwater habitats) was in two days after neap tide and freshwater blue-green algae was in intermediate tide in response to changes in mixing conditions. The distribution of marine habitat diatoms and freshwater blue-green algae were positively correlated with salinity whereas freshwater green algae and freshwater habitat diatoms were negatively correlated with salinity. This study concludes that saltwater intrusion and mixing conditions driven by tidal forcing mainly controlled the species composition and their habitats in the Chikugo River estuary.