Sweeney Alison, Sañudo-Wilhelmy Sergio A
Illinois Wesleyan University, Bloomington, IL 61701, USA.
Mar Pollut Bull. 2004 Apr;48(7-8):663-70. doi: 10.1016/j.marpolbul.2003.10.009.
A suite of dissolved trace metals (Ag, Cd, Cu and Pb), inorganic nutrients (NO(3), PO(4)), and chlorophyll a was measured along a 55 mile transect from the East River into western and central Long Island Sound. The main objectives of this study were to determine the relative levels of contamination from sewage, and to assess its possible biological impact on local waters. The East River-Long Island Sound system receives large volumes of treated sewage and industrial effluent as a result of the heavy urbanization of the area. Despite these strong environmental pressures, this study is among the first to report dissolved metal levels from that region. Consistent with the locations of anthropogenic sources, a strong east-west concentration gradient was observed for Ag, Pb, NO(3) and PO(4) with the highest levels found in the East River. In contrast, dissolved Cd and Cu were relatively constant throughout the area of study, suggesting that sewage sources have a more limited influence on the levels of those metals. Remobilization from contaminated sediments may represent the primary source of Cd and Cu to the Long Island Sound under low-runoff conditions in summer. Chlorophyll a concentrations, used as an indicator of total biomass, were also low in the East River. These low chlorophyll concentrations could not be explained by nutrient or light limitation, water column stratification, or to advection of phytoplankton out of the river during tidal flushing. These preliminary results suggest a potential toxic effect of sewage on the biological communities of the East River.
沿着一条从东河到长岛海峡西部和中部长达55英里的断面，对一系列溶解态痕量金属（银、镉、铜和铅）、无机营养物（硝酸盐、磷酸盐）以及叶绿素a进行了测量。本研究的主要目的是确定污水污染的相对水平，并评估其对当地水域可能产生的生物影响。由于该地区的高度城市化，东河 - 长岛海峡系统接纳了大量经过处理的污水和工业废水。尽管存在这些强大的环境压力，但本研究是首批报道该地区溶解态金属水平的研究之一。与人为污染源的位置一致，观察到银、铅、硝酸盐和磷酸盐存在强烈的东西向浓度梯度，其中东河的含量最高。相比之下，溶解态镉和铜在整个研究区域相对恒定，这表明污水源对这些金属的水平影响较为有限。在夏季径流较低的情况下，受污染沉积物的再活化可能是长岛海峡镉和铜的主要来源。叶绿素a浓度用作总生物量的指标，在东河中也较低。这些低叶绿素浓度无法用营养物或光照限制、水柱分层或潮汐冲刷期间浮游植物被平流带出河流来解释。这些初步结果表明污水对东河生物群落可能产生毒性作用。
