Metal levels and toxicity of sediments from the Mobile River/Chickasaw Creek watershed using chemical, ecological, and toxicological evaluations

The Chickasaw Creek/Mobile River watershed (Mobile, Alabama, USA) in the Mobile Delta is an area with a large industrial presence. Contamination of surface water and sediment as a result of airborne emission and effluent discharge from these facilities is of great concern. To test for contamination, a chemical and biological assessment of several locations was performed and compared to previous studies. Results indicated low levels of metals away from areas of high industrial density, while locations within the vicinity of industries contained higher concentrations of heavy metals. Benthic invertebrate sampling indicated large numbers of aquatic polychaetes typically associated with impacted sediments. To assess potential bioaccumulation from sediments, a 28-day sediment bioaccumulation test was conducted using Lumbriculus variegatus. Bioaccumulation of metals occurred in all sediments; however, there was not a significant difference in tissue concentrations between sample sites.