Four-site Analysis of Variance (ANOVA) Results for Levels of Total Organic Contaminants in Fish Captured for Davis Pond Postdiversion Sampling, 2007-2009

The diversion of freshwater from the Mississippi River is intended to mitigate saltwater intrusion from the Gulf of Mexico and to lessen the concomitant loss of wetland areas. Though effective, freshwater diversion can affect wildlife and habitat; therefore, prediversion and postdiversion data collections are necessary to identify effects. The Davis Pond freshwater diversion area is located between the Mississippi River and Bayou Lafourche and extends to Barataria Bay Basin, Louisiana. Results and interpretations from the prediversion biomonitoring done in 2001 - which included data on fish, eagles, and bivalves - are presented in the U.S. Geological Survey (USGS) Scientific Investigations Report 2008-5067, "Davis Pond Freshwater Prediversion Biomonitoring Study: Freshwater Fisheries and Eagles." The postdiversion data generated approximately 6 years later from the sampling of fish whole bodies are presented here in this USGS Data Series. An accompanying log of postdiversion study site photographs was also produced in USGS Data Series 605, "Photographic Images Captured While Sampling for Bald Eagles near the Davis Pond Freshwater Diversion Structure in Barataria Bay, Louisiana (2009-10).

This table presents the results of statistical analysis of variance of organic contaminants in fish sampled pre- and postdiversion of Davis Pond. Data collected consist of measurements of organic contaminants detected in largemouth bass, blue catfish and striped mullet samples collected in 2001 (prediversion) and 2007-2009 (6-8 years postdiversion). Total amounts of organic contaminants were compared using two-way and three-way analysis of variance (ANOVA) tests. Organic contaminants tested for include aliphatic hydrocarbons (AHs), polycyclic aromatic hydrocarbons (PAHs), organochlorines (OCs), DDT, DDE, and polychlorinated biphenyls (PCBs). A four-site analysis was performed to compare levels of contamination in fish drawn from the Mississippi River, and those collected from three marsh sites (Lake Cataouatche, Bayou Couba, and Lake Salvador).

从密西西比河（Mississippi River）开展淡水分流工程，旨在缓解墨西哥湾（Gulf of Mexico）引发的盐水入侵问题，并减轻伴随发生的湿地面积缩减。尽管淡水分流具备实效，但其仍可能对野生生物及其栖息地造成影响，因此开展分流前与分流后的数据采集工作，对识别此类影响而言必不可少。戴维斯塘淡水分流区地处密西西比河与拉富什溪（Bayou Lafourche）之间，延伸至路易斯安那州（Louisiana）的巴拉塔里亚湾盆地（Barataria Bay Basin）。2001年开展的分流前生物监测工作（涵盖鱼类、鹰类与双壳类生物数据），其结果与解读已收录于美国地质调查局（U.S. Geological Survey, USGS）《科学调查报告2008-5067：戴维斯塘淡水分流前生物监测研究：淡水渔业与鹰类》（"Davis Pond Freshwater Prediversion Biomonitoring Study: Freshwater Fisheries and Eagles"）。本次美国地质调查局数据系列中，收录了约6年后开展的全鱼体采样所得到的分流后数据。配套的分流后研究场地摄影日志则收录于美国地质调查局数据系列605：《路易斯安那州巴拉塔里亚湾戴维斯塘淡水分流设施附近白头海雕采样过程中拍摄的影像（2009-2010年）》（"Photographic Images Captured While Sampling for Bald Eagles near the Davis Pond Freshwater Diversion Structure in Barataria Bay, Louisiana (2009-10)"）。

本表格呈现了戴维斯塘淡水分流前后鱼类体内有机污染物的方差统计分析结果。本次采集的数据，为2001年（分流前）与2007-2009年（分流后6至8年）采集的大口黑鲈、蓝鲶与条纹鲻鱼样本中检测到的有机污染物含量测定值。本次采用双向与三向方差分析（analysis of variance, ANOVA）检验方法，对有机污染物总含量进行对比。本次检测的有机污染物涵盖脂肪烃（aliphatic hydrocarbons, AHs）、多环芳烃（polycyclic aromatic hydrocarbons, PAHs）、有机氯（organochlorines, OCs）、DDT、DDE以及多氯联苯（polychlorinated biphenyls, PCBs）。本次开展了四站点分析，以对比取自密西西比河的鱼类与取自三处沼泽站点（卡图阿奇湖、库巴溪与萨尔瓦多湖）的鱼类污染物含量水平。