ENVR 84 |
| As part of the Interagency Performance Evaluation Task Force (IPET), we investigated environmental impacts in the vicinity of New Orleans, Louisiana, following Hurricane Katrina. An environmental concern post-Katrina was chemical contamination impacts in surrounding wetlands. We compared sediment chemistry, toxicity and benthic community structure at sites in the vicinity of functioning and non-functioning pumping stations that discharged into Violet Marsh during Hurricane Katrina. Sediments were analyzed for 163 organic and inorganic chemicals. Whole sediment 10-day toxicity tests were conducted using the estuarine amphipod, Leptocheirus plumulosus. A comparison of sediment chemistry data from this study made with other studies showed that the relative concentrations for four representative chemicals (arsenic, benzo[a]pyrene, DDD and lead) were generally lower than the concentrations reported within New Orleans by other investigators. This suggests that sediment-associated contaminants present within the levees during Katrina may not have been pumped into the marsh in appreciable quantities. A comparison of the bioassay and chemical analysis results suggested a relationship between the concentrations of several chemicals analyzed in the sediment and mortality of L. plumulosus for several samples. In general, Violet Marsh samples further from the levees had lower chemical concentrations and resulted in less L. plumulosus mortality relative to other samples. The benthic community data suggested that floodwater pumping affected benthic assemblages as indicated by the low abundance, diversity, altered species composition and high degree of variability in pumped areas. The cause for such effects on benthos is likely due to unmeasured physical, chemical or biological stressors. |
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Natural Disasters: Identifying and Addressing Environmental Concerns
1:30 PM-3:35 PM, Monday, April 7, 2008 Morial Convention Center -- Rm. 236, Oral
Division of Environmental Chemistry |