Skip Links

USGS - science for a changing world

Open-File Report 2012–1172

Radioisotopic Data of Sediment Collected in Mobile and Bon Secour Bays, Alabama

By Marci E. Marot and Christopher G. Smith

Thumbnail image of report cover and link to report PDF


The focus of this study was to determine the extent of natural and (or) anthropogenic impacts on the sedimentary records of Mobile and Bon Secour Bays, Alabama during the last 150 years. These bays are unique in that anthropogenic activities are generally widespread and span both the eastern and western shorelines. However, there is a clear distinction in the types of human development and infrastructure between the western and eastern shorelines. These activities and the differences in land-use and -change influence the overall supply and remobilization of sediment to and within the bay. These factors could subsequently threaten the health and integrity of these environments and their ability to mitigate against long-term processes associated with climate change. In an attempt to characterize long-term accretion rates within the Mobile Bay Estuarine System (MBES), seven box cores were collected and analyzed for excess lead-210 (210Pbxs, the difference between total and supported 210Pb) and cesium-137 (137Cs) activities. The MBES receives sediment and water from the Alabama and Tombigbee River watersheds, which converge into the Mobile-Tensaw River (MTR) system just prior to discharging into Mobile Bay. Riverine discharge from the MTR system to the bay is second only to the Mississippi River discharge to the Gulf of Mexico for the conterminous United States.

First posted August 30, 2012

For additional information contact:
Marci E. Marot
St. Petersburg Coastal and Marine Science Center
600 4th Street South
St. Petersburg, FL 33701

St. Petersburg Coastal and Marine Science Center

Part or all of this report is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge.

Suggested citation:

Marot, M.E., and Smith, C.G., 2012, Radioisotopic data of sediment collected in Mobile and Bon Secour Bays, Alabama: U.S. Geological Survey Open-File Report 2012–1172, 15 p.



Data Collection and Processing

Collection and Processing of Box Cores

Gamma Spectroscopy Analyses

Alpha Spectroscopy Analyses

Results and Discussion


References Cited

Accessibility FOIA Privacy Policies and Notices logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Contact USGS
Page Last Modified: Saturday, January 12, 2013, 03:26:57 PM