2002 Progress Report: Resolution of Sedimentation Rates in Impacted Coastal Environments Using 137Cs and 210Pb Markers: Dog River and Fowl River Embayments

EPA Grant Number: R827072C032
Subproject: this is subproject number 032 , established and managed by the Center Director under grant R827072
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: Alabama Center For Estuarine Studies (ACES)
Center Director: Shipp, Robert L.
Title: Resolution of Sedimentation Rates in Impacted Coastal Environments Using 137Cs and 210Pb Markers: Dog River and Fowl River Embayments
Investigators: Sanders, Justin , Fearn, Miriam , Haywick, Douglas
Institution: University of South Alabama
EPA Project Officer: Packard, Benjamin H
Project Period: July 1, 2000 through December 31, 2003
Project Period Covered by this Report: July 1, 2001 through December 31, 2002
RFA: Alabama Center For Estuarine Studies (ACES) (1999) RFA Text |  Recipients Lists
Research Category: Targeted Research

Objective:

The objective of this research project is to determine sedimentation rates for multiple sites on Dog River and Fowl River using the technique of high-resolution gamma-ray spectrometry. The sampling sites have been chosen to allow different tributaries of Dog River to be compared regarding the degree to which development in western Mobile County has affected runoff sedimentation in the river.

Progress Summary:

This year's activities have focused on the continuing gamma ray analysis of sediment cores, as well as grain-size analysis of the sediment from selected cores. The cores were previously extracted from six sites on Dog River and its tributaries. Four sites were in the main channel of the river: near its mouth (site DRA), upstream of the mouth (site DRB), at the mouth of Moores Creek (site DRC), and downstream of Luscher Park (site DRD). The two sites in tributaries were in Rabbit Creek (site DRE) and Hall's Mill Creek (site DRF). In Fowl River, cores were taken from three sites extending from upstream of the Fowl River Bridge (site FRA) to well upstream of the Bellingrath Estate (sites FRB and FRC). Finally, cores were extracted from two sites (CVA and CVB) in Converse Reservoir (Big Creek Lake) to provide a contrasting sediment environment to the two rivers. Duplicate archival cores were taken at each site. The cores were extruded and sliced into 2-cm samples (1 cm for the Converse Reservoir cores) and air dried.

Gamma ray analysis of the samples from the cores was performed using a high-purity germanium (HPGe) spectrometer system. Low-background radiation shielding is used with the spectrometer to minimize radiation from the surroundings to overwhelm the low-level radiation in each sample. Each sample was counted for 54,000 seconds (about 15 hours). Cores from all six Dog River sites, one of the Fowl River sites, and one Converse Reservoir site have been analyzed for 137Cs. The analysis of these eight cores has required measuring the 137Cs gamma ray emission from approximately 300 sample slices. One Converse Reservoir core and two cores from Fowl River remain to be analyzed.

An unnormalized yield of 137Cs can be obtained for each core slice from the number of 137Cs gamma rays counted in a fixed time divided by the dry mass of each sample. A depth profile of the yield of 137Cs allows the 1954 horizon to be determined as the depth of the onset of 137Cs. Such a depth profile is provided in Figure 1 for core DRE1. Preliminary results from the 137Cs analysis are provided in Table 1. Accumulation and sedimentation rates in Dog River are noticeably higher at the mouth of Moores Creek (DRC1) and in Hall's Mill Creek (DRF1), while Rabbit Creek (DRE1), which has seen less development than the other two tributaries, is more similar to the main channel of the river (DRA1, DRB1, and DRD3) and to Fowl River (FRB1).

Figure 1. Cs Depth Profile for Core DRE1

Table 1. Average Accumulation and Sedimentation Rates

Core
Accumulation Rate (cm yr-1)
Sedimentation Rate (g cm-2 yr-1)
DRA1
0.72 ± 0.04
0.58 ± 0.03
DRB1
1.13 ± 0.04
0.74 ± 0.03
DRC1
2.30 ± 0.04
1.15 ± 0.02
DRD3
1.16 ± 0.04
0.43 ± 0.02
DRE1
1.40 ± 0.04
0.50 ± 0.02
DRF1
1.94 ± 0.08
1.07 ± 0.03
FRB1
1.06 ± 0.04
0.36 ± 0.02
CVA1
0.26 ± 0.02
0.17 ± 0.02
CVB1
0.21 ± 0.02
0.27 ± 0.03

Grain-size analysis also has been performed on cores DRC1, DRD3, DRE1, DRF1, and FRB1 following gamma ray analysis. Because 137Cs preferentially binds to clay in sediment, knowledge of the clay content of the sediment will help in the more detailed interpretation of the 137Cs depth profiles. Figure 2 presents a grain-size histogram from a typical slice. Silt and clay are the primary constituents of this particular slice, and consequently, it would be expected that this slice is representative of one in which 137Cs is effectively bound.

Figure 2. Grain Size Histogram, Core DRF1, Sample Interval 2-4 cm

Future Activities:

We will continue and complete the 137Cs and 210Pb analyses, and also will correlate the results of grain-size analysis with the 137Cs analysis.

Journal Articles:

No journal articles submitted with this report: View all 6 publications for this subproject

Supplemental Keywords:

high-resolution gamma-ray spectrometry, analysis of sediment cores, silt and clay, ecosystem, ecosystem protection, ecology, ecological effects, ecological indicators, environmental exposure, geographic area, water, water use, aquatic ecosystem, coastal ecosystem, coastal environments, estuary, estuaries, estuarine research, estuarine waters, environmental chemistry, chemistry, risk, assessment, indicators, Alabama, AL, human modifications., RFA, Scientific Discipline, Geographic Area, ECOSYSTEMS, Water, Ecosystem Protection/Environmental Exposure & Risk, Aquatic Ecosystems & Estuarine Research, estuarine research, Environmental Chemistry, Ecosystem/Assessment/Indicators, Ecosystem Protection, State, Chemistry, Soils, Restoration, Aquatic Ecosystem, Aquatic Ecosystems, Terrestrial Ecosystems, Ecological Monitoring, Ecology and Ecosystems, Aquatic Ecosystem Restoration, Ecological Indicators, coastal ecosystem, river discharge, wetlands, estuaries, high resolution spectroscopy, watersheds, erosion, shorelines, Alabama (AL), coastal environments, anthropogenic impact, wetland stabilization, Alabama estuaries, rivers, ecosystem, environmental indicators, estuarine waters, water quality, human modifications, sediment dynamics, riverine ecosystems

Relevant Websites:

http://www.southalabama.edu/aces/ Exit
http://www.usouthal.edu/geography/haywick/weeksbay.htm Exit
http://www.usouthal.edu/geography/fearn/research.htm Exit

Progress and Final Reports:

Original Abstract
  • 2001
  • 2003
  • Final

  • Main Center Abstract and Reports:

    R827072    Alabama Center For Estuarine Studies (ACES)

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R827072C001 Fluorescent Whitening Agents As Facile Pollution Markers In Shellfishing Waters
    R827072C002 Red Snapper Demographics on Artificial Reefs: The Effect of Nearest-Neighbor Dynamics
    R827072C003 Stabilization of Eroding Shorelines in Estuarine Wave Eliminates with Constructed Fringe Wetlands Incorporating Offshore Breakwaters
    R827072C004 Interaction Between Water Column Structure and Reproduction in Jellyfish Populations Of Mobile Bay (SGER)
    R827072C005 Effects of Variation in River Discharge and Wind-Driven Resuspension on Higher Trophic Levels in the Mobile Bay Ecosystem
    R827072C006 Results of Zooplankton Component
    R827072C007 Benthic Study Component
    R827072C008 A Preliminary Survey of Macroalgal and Aquatic Plant Distribution in the Mobile Tensaw Delta
    R827072C009 Fisheries-induced changes in the structure and function of shallow water "nursery habitats": an experimental assessment
    R827072C010 Effects Of Variation in River Discharge and Wind-Driven Resuspension on Lower Trophic Levels of the Mobile Bay Ecosystem
    R827072C011 Evaluation of Alabama Estuaries as Developmental Habitat for Juvenile Sea Turtles
    R827072C012 Effects of Salinity Stress on Natural and Anthropogenically-Derived Bacteria in Estuarine Environments
    R827072C013 The Role of Land-Use/Land-Cover and Sub-estuarine Ecosystem Nitrogen Cycling in the Regulation of Nitrogen Delivery to a River Dominated Estuary; Mobile Bay, Alabama
    R827072C014 Environmental Attitudes of Alabama Coastal Residents: Public Opinion Polls and Environmental Policy
    R827072C015 Synthesis and Characterization of an Electrochemical Peptide Nucleic Acid Probe
    R827072C016 Determinants of Small-Scale Variation in the Abundance of the Blue Crab Callinectes Sapidus
    R827072C017 Effects of Estrogen Pollution on the Reproductive Fitness of the Gulf Pipefish, Syngnathus scovelli
    R827072C019 A Model for Genetic Diversity Aquatic Insects of the Mobile/Tensaw River Delta
    R827072C020 Evaluating Trophic Processes as Indicators of Anthropogenic Eutrophication in Coastal Ecosystems: An Exploratory Analysis
    R827072C021 Effects of Anthropogenic Eutrophication on the Magnitude and Trophic Fate of Microphytobenthic Production in Estuaries
    R827072C022 Characteristics of Ship Waves and Wind Waves in Mobile Bay
    R827072C023 Methods Comparison Between Stripping Voltammetry and Plasma Emission Spectroscopy for Metals in Mobile Bay
    R827072C024 Changes in Water Conditions and Sedimentation Rates Associated With Construction of the Mobile Bay Causeway
    R827072C025 Cold-Induced Hibernation of Marine Vibrios in the Gulf of Mexico: A Study of Cell-Cell Communication and Dormancy in Vibrio vulnificus
    R827072C026 Holocene Sedimentary History of Weeks Bay, AL: Human and Natural Impacts on Deposition in a Gulf Coast Estuary
    R827072C027 Shelter Bottlenecks and Self-Regulation in Blue Crab Populations: Assessing the Roles of Nursery Habitats and Juvenile Interactions for Shelter Dependent Organisms
    R827072C028 Predicting Seagrass Survival in Nutrient Enriched Waters: Toward a New View of an Existing Paradigm
    R827072C029 DMSP and its Role as an Antioxidant in the Salt Marsh Macrophyte Spartina alterniflora
    R827072C030 A Preliminary Survey of Aerial and Ground-Dwelling Insects of the Mobile/Tensaw Delta
    R827072C031 Natural Biogeochemical Tags of Striped Mullet, Mugil cephalus, Estuarine Nursery Areas in the North Central Gulf of Mexico
    R827072C032 Resolution of Sedimentation Rates in Impacted Coastal Environments Using 137Cs and 210Pb Markers: Dog River and Fowl River Embayments
    R827072C033 Investigation of the Use of Pulse Amplitude Modulated (PAM) Fluorometry as an Indicator of Submerged Aquatic Vegetation Health in Mobile Bay
    R827072C034 Influence of Invasive Plant Species in Determining Diversity of Aquatic Vegetation in the Mobile-Tensaw Delta
    R827072C035 The Influence of Shallow Water Hydrodynamics on the Importance of Seagrass Detritus in Estuarine Food Webs
    R827072C036 Food Web Interactions, Spatial Subsidies and the Flow of Energy Between the Mobile Bay Delta and Offshore Waters: A SGER Proposal to the Alabama Center for Estuarine Studies
    R830651C001 Meteorological Modeling of Hurricanes and Coastal Interactions: A Stability Study For Vertical Pressure Levels
    R830651C002 Characterization of Glycoprotein Cues Used by the Parasitic Rhizocephalan Barnacle Loxothylacus texanus To Identify Its Blue Crab Host, Callinectes sapidus
    R830651C003 Survey of Diamondback Terrapin Populations in Alabama Estuaries
    R830651C004 An Assessment of Environmental Contaminant Levels in Water and Dragonfly Larvae Tissues from the Mobile/Tensaw Delta