Dissolved Trace Element Concentrations in the East River-Long Island Sound System: Relative Importance of Autochthonous versus Allochthonous Sources

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• 作者：Nathaniel J. Buck ; Christopher J. Gobler ; and Sergio A. Sañ ; udo-Wilhelmy
• 刊名：Environmental Science & Technology
• 出版年：2005
• 出版时间：May 15, 2005
• 年：2005
• 卷：39
• 期：10
• 页码：3528 - 3537
• 全文大小：335K
• 年卷期：v.39,no.10(May 15, 2005)
• ISSN：1520-5851

文摘

Dissolved trace metal (Ag, Cd, Cu, Fe, Ni, Pb, and Zn),inorganic nutrient (NO₃, NH₄, PO₄, H₄SiO₄), and DOCconcentrations were measured at 43 stations during low(July 2000) and high (April 2001) river discharge conditionsin surface waters of Long Island Sound (LIS). To evaluatethe impact of fluvial sources to the total metal budgetof the sound, samples were collected from major tributariesdischarging into LIS (Thames, Quinnipiac, Housatonic,Connecticut, and East Rivers). To compare LIS with othercoastal embayments, samples were also collected fromfive LIS coastal embayments (Manhassett Bay, HuntingtonHarbor, Oyster Bay, Hempstead Harbor, and Port JeffersonHarbor), which are monitored by the U.S. National Status andTrends Program. Metal and nutrient distributions identifiedtwo biogeochemical regimes within LIS: an area ofrelatively high nutrient and metal concentrations in theEast River/Narrows region in western LIS and an area inthe eastern region of the sound that had comparatively lowerconcentrations. Mass balance estimates indicated that,during low flow conditions, the East River was the dominantallochthonous source of most trace metals (Ag, Cd, Cu,Ni, Zn) and inorganic nutrients (NO₃ and PO₄); during highflow conditions, the most influential source of theseconstituents was the Connecticut River. Mass balanceestimates also evidenced a large autochthonous sourceof Cu, Ni, and Zn, as their spatial distributions displayedelevated concentrations away from point sources such asthe East River. Principal component analysis suggestedthat metal and nutrient distributions in the LIS system wereinfluenced by different seasonal processes: remobilizationfrom contaminated sediments, anthropogenic inputsfrom sewage discharges and phytoplankton scavengingduring the spring freshet, and benthic remobilization duringsummer conditions.