Particulate N and P characterizing the fate of nutrients along the estuarine gradient of the River Neva (Baltic Sea)
Particulate N and P characterizing the fate of nutrients along the estuarine gradient of the River Neva (Baltic Sea)
复制标题
表征涅瓦河（波罗的海）河口梯度营养物命运的颗粒 N 和 P
DOI：
10.1016/j.ecss.2004.04.016
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发表时间：
2004
影响因子：
2.8
通讯作者：
H. Pitkänen
中科院分区：
文献类型：
--
作者：
J. Lehtoranta;A. Heiskanen;H. Pitkänen
由于圣彼得堡的高营养负荷，涅瓦河河口出现富营养化。先前的研究表明，大部分氮和磷负荷有效地保留在河口。然而，河口海域颗粒物氮和磷的去向仍不确定。因此，研究了涅瓦河河口梯度沿线近期沉积物中碳、氮和磷沉积速率以及沉积物有机质（烧失量，LOI）、总氮（TN）和磷（TP）的变化。氮和磷的高总沉降率表明氮和磷在河口内的有效滞留。沿河口梯度沉降颗粒C和N浓度的增加与沉积物中有机质和TN浓度和埋藏的增加一致。然而，虽然沉降物中的磷浓度也沿着河口梯度增加，但沉积物中的总磷浓度却下降了。这种下降与沉积物有机质浓度的增加显着相关，但与河口梯度沿线的水深无关。结果表明，沿河口梯度有机质的增加和水动力条件的变化会降低顶部0-10 cm沉积物层保留磷的能力。沉降颗粒物中氮的平均浓度为23.3 mg g−1DW，沉积物表面的氮平均浓度为6.5 mg g−1DW。相应的 P 值彼此更接近，即分别为 3.3 和 2.8 mg g−1DW。这表明，在表层沉积物（0-1 cm）中，沉降的 P 比 N 更有效地保留和/或积累。相反，在 0-10 cm 沉积物层中，N 似乎比 P 更有效地保留。
The estuary of the River Neva is eutrophied due to the high nutrient load from St. Petersburg. Previous studies have suggested that a large part of the N and P load is efficiently retained in the estuary. However, the fate of particulate N and P in the estuarial sea area has remained uncertain. Variations in the C, N and P sedimentation rate and in sediment organic matter (loss on ignition, LOI), total nitrogen (TN) and phosphorus (TP) were therefore studied in the recent sediment deposits along the estuarine gradient of the River Neva. The high gross sedimentation rate of N and P indicated efficient retention of both N and P in the inner estuary. An increase in the concentrations of settling particulate C and N along the estuarine gradient was consistent with the increase in the concentrations and burial of organic matter and TN in sediments. However, although the concentration of P in settling matter also increased along the estuarine gradient, a decrease was noted in the sediment TP concentration. This decrease correlated significantly with an increase in the concentration of sediment organic matter, but not with water depth along the estuarine gradient. The result indicates that an increase in organic matter and changes in hydrodynamic conditions along the estuarine gradient can reduce the capacity of the top 0–10 cm sediment layer to retain P. The average concentration of N in settling particulate matter was 23.3 mg g−1DW and in the sediment surface 6.5 mg g−1DW. Corresponding values for P were much closer to each other, that is, 3.3 and 2.8 mg g−1DW, respectively. This suggests that, in the surface sediments (0–1 cm), settled P was more efficiently retained and/or accumulated than N. In contrast, in the 0–10 cm sediment layer N seemed to be more efficiently retained than P.