Lead Concentrations in Fish from the Davis Pond Freshwater Postdiversion Sampling (2007-2009) with a Comparison to Prediversion Levels (2001)

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).

Figures 17A and 17C represent the concentration of lead detected in largemouth bass, blue catfish and striped mullet samples collected in 2007-2009, approximately six years after the Davis Pond freshwater diversion structure was operational. Figure 17B compares these concentrations to those collected in the 2001 prediversion study. Samples are from the Mississippi River, Lake Cataouatche, Bayou Couba, and Lake Salvador.

从密西西比河调配淡水，旨在缓解墨西哥湾引发的咸水入侵，并减轻伴随发生的湿地面积流失。尽管淡水调蓄工程成效显著，但仍可能对野生生物及其栖息环境造成影响，因此开展调蓄前与调蓄后的数据集采集工作，对明确其生态影响至关重要。
戴维斯塘淡水调蓄工程区位于密西西比河与拉富什河湾之间，延伸至路易斯安那州的巴拉塔里亚湾流域。
2001年开展的调蓄前生物监测工作（涵盖鱼类、鹰类及双壳类生物数据），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：戴维斯塘淡水调蓄前生物监测研究：淡水渔业与鹰类》。
本份美国地质调查局数据系列则收录了调蓄工程运行约6年后，通过全鱼体采样获取的调蓄后监测数据。
同期还编制了调蓄后研究样地的摄影日志，收录于美国地质调查局数据系列605：《2009-2010年路易斯安那州巴拉塔里亚湾戴维斯塘淡水调蓄设施周边白头海雕采样过程中拍摄的影像资料》。
图17A与图17C展示了2007-2009年（即戴维斯塘淡水调蓄设施投用约6年后）采集的大口黑鲈、蓝鲶及条纹鲻样本中的铅浓度检测结果。图17B将上述浓度数据与2001年调蓄前监测研究的对应数据进行了对比。本次采样样本取自密西西比河、卡托阿奇湖、库巴河湾及萨尔瓦多湖。