Nutrients (organic C, P, N, Si) in the eutrophic River Loire (France) and its estuary
Nutrients (organic C, P, N, Si) in the eutrophic River Loire (France) and its estuary
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DOI：
10.1016/0272-7714(88)90071-6
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发表时间：
1988-12
影响因子：
2.8
通讯作者：
M. Meybeck;G. Cauwet;S. Dessery;M. Somville;D. Gouleau;G. Billen
中科院分区：
文献类型：
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作者：
M. Meybeck;G. Cauwet;S. Dessery;M. Somville;D. Gouleau;G. Billen
1982 ~ 1985年，在卢瓦尔河口进行了13条低潮时的等深线纵剖面测量。营养盐（SiO2、NO3−、NH 4+、PO 3 −4、颗粒有机碳或POC）模式因季节、河口段（河流、河口内上部、淡水-咸水界面FSI上游、河口内下部（以高浊度区（HTZ）为特征）、河口外）和河流流量而变化很大。生物过程占主导地位。在富营养化的卢瓦尔河（夏季色素> 100 μg l−1），藻类的高生产力（藻类POC > 3 mg l−1）导致SiO2、PO 43 −、NO3−的严重耗竭。在细菌活动强烈的HTZ中，巨大的生物量（55 000吨藻类POC/年）被降解。因此，通常会再生溶解的SiO2和PO 43-，显著的NH 4+最大值，而NO3-在HTZ接近缺氧时是保守的或耗尽的。可以考虑其他过程，包括化肥计划（PO 43-，NH 4+）和水热发电厂（NH 4+）的污染。在浑浊度较低的外河口，营养盐一般是保守的。在最低氯度段（Cl−< 1 g kg−）和FSI上游（此处定义为Cl−增加100%）观察到浓度的主要变化。SiO2和NO2−对海洋的营养输入没有显著影响，但PO 43 −和NH 4+增加了70%和180%，POC减少了60%。奇怪的水文事件，特别是一些洪水，可能会扰乱，甚至掩盖通常的季节性模式中观察到的配置文件。
The Loire estuary has been surveyed from 1982 to 1985 by 13 isochronous longitudinal profiles realized at low tide. Nutrient (SiO2, NO3−, NH4+, PO3−4, particulate organic carbon or POC) patterns are very variable depending on the season, the estuarine section [river, upper-inner estuary, upstream of the fresh-water-saline-water interphase FSI, the lower-inner estuary characterized by the high turbidity zone (HTZ), the outer estuary] and the river discharge. Biological processes are dominant. In the eutrophied River Loire (summer pigment > 100 μg l−1), the high algal productivity (algal POC > 3 mg l−1) results in severe depletion of SiO2, PO43−, NO3−. The enormous biomass (55 000 ton algal POC/year) is degraded in the HTZ where bacterial activity is intense. As a result, there is generally a regeneration of dissolved SiO2and PO43−, a marked NH4+maximum, while NO3−is conservative or depleted when the HTZ is nearly anoxic. Other processes can be considered including pollution from fertilizer plans (PO43−, NH4+) and from a hydrothermal power plant (NH4+). In the less turbid outer estuary, nutrients are generally conservative. Major variations of concentrations are observed in the lowest chlorinity section (Cl−< 1 g kg−) and also upstream the FSI, defined here as a 100% increase in Cl−. Nutrient inputs to the ocean are not significantly modified for SiO2and NO2−, but are increased by 70% and 180% for PO43−and NH4+and depleted by 60% for POC. Odd hydrological events, especially some floods, may perturbate or even mask the usual seasonal pattern observed in profiles.