Exchange of Nitrogen and Phosphorus Between a Shallow Lagoon and Coastal Waters
Exchange of Nitrogen and Phosphorus Between a Shallow Lagoon and Coastal Waters
复制标题
浅泻湖和沿海水域之间的氮和磷交换
DOI：
--
复制
发表时间：
2014
影响因子：
2.7
通讯作者：
K. McGlathery
中科院分区：
文献类型：
--
作者：
M. Hayn;R. Howarth;Roxanne Marino;N. Ganju;P. Berg;K. Foreman;A. Giblin;K. McGlathery
西法尔茅斯港是科德角的一个浅水泻湖，自20世纪90年代中后期以来，由于被市政污水处理厂污染的地下水流入，其氮负荷增加了三倍。我们测量了氮和磷在港口和Buzzards湾沿岸水域之间的交换在几年里当港口经历氮负荷升高的时候。在夏季，该港口不仅保留了整个流域的氮负荷，而且还从Buzzards湾净进口氮。在春季和秋季，该港口向Buzzards湾净出口氮气。我们没有测量冬季的出口量，但假设冬季净出口量低于负荷的112%，那么港口的年出口量不到流域氮负荷的一半。对于磷，该港口在春季和夏季从沿海水域净进口，在秋季净出口。尽管港口的氮负荷大幅增加，但夏季从Buzzards湾进口的磷足以维持夏季初级生产力的氮限制。我们的研究结果表明，当与沿海水域交换有足够的磷供应时，由底栖生物生产者主导的浅层系统有可能保留大量的陆地氮负荷。
West Falmouth Harbor, a shallow lagoon on Cape Cod, has experienced a threefold increase in nitrogen load since the mid- to late 1990s due to input from a groundwater plume contaminated by a municipal wastewater treatment plant. We measured the exchange of nitrogen and phosphorus between the harbor and the coastal waters of Buzzards Bay over several years when the harbor was experiencing this elevated nitrogen load. During summer months, the harbor not only retained the entire watershed nitrogen load but also had a net import of nitrogen from Buzzards Bay. During the spring and fall, the harbor had a net export of nitrogen to Buzzards Bay. We did not measure the export in winter, but assuming the winter net export was less than 112 % of the load, the harbor exported less than half of the watershed nitrogen load on an annual basis. For phosphorus, the harbor had a net import from coastal waters in the spring and summer months and a net export in the fall. Despite the large increase in nitrogen load to the harbor, the summertime import of phosphorus from Buzzards Bay was sufficient to maintain nitrogen limitation of primary productivity during the summer. Our findings illustrate that shallow systems dominated by benthic producers have the potential to retain large terrestrial nitrogen loads when there is sufficient supply of phosphorus from exchange with coastal waters.