Pruell Richard J, Taplin Bryan K, Miller Kenneth M
U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Atlantic Ecology Division, 27 Tarzwell Drive, Narragansett, RI 02882, USA.
U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Atlantic Ecology Division, 27 Tarzwell Drive, Narragansett, RI 02882, USA.
Mar Pollut Bull. 2017 May 15;118(1-2):41-47. doi: 10.1016/j.marpolbul.2017.02.009. Epub 2017 Feb 12.
Nitrogen isotope ratios (δN) in juvenile winter flounder, Pseudopleuronectes americanus, were used to examine changes in nitrogen inputs to several Rhode Island, USA estuarine systems. Fish were collected over two three-year periods with a ten-year interval between sampling periods (2002-2004 and 2012-2014). During that interval numerous changes to nutrient management practices were initiated in the watersheds of these estuarine systems including the upgrade of several major wastewater treatment facilities that discharge to Narragansett Bay, which significantly reduced nitrogen inputs. Following these reductions, the δN values of flounder in several of the systems decreased as expected; however, isotope ratios in fish from upper Narragansett Bay significantly increased. We believe that low δN values measured in 2002-2004 were related to concentration-dependent fractionation at this location. Increased δN values measured between 2012 and 2014 may indicate reduced fractionation or that changes in wastewater treatment processes altered the nitrogen isotopic ratios of the effluents.
利用美洲黄盖鲽幼鱼的氮同位素比率（δN）来研究美国罗德岛州几个河口系统的氮输入变化。在两个三年期间收集鱼类样本，采样期之间间隔十年（2002 - 2004年和2012 - 2014年）。在此期间，这些河口系统流域的养分管理措施发生了许多变化，包括对几个向纳拉甘西特湾排放污水的主要污水处理设施进行升级，这显著减少了氮输入。氮输入减少后，几个系统中的黄盖鲽δN值如预期那样下降；然而，纳拉甘西特湾上游鱼类的同位素比率显著增加。我们认为，2002 - 2004年测得的低δN值与该地点的浓度依赖性分馏有关。2012年至2014年期间测得的δN值增加可能表明分馏减少，或者污水处理过程的变化改变了废水的氮同位素比率。
