{
    "tag": 21110,
    "title": "Collection, analysis, and age-dating of sediment cores from coastal wetlands in Oyster Bay, Alabama, 2021",
    "pubdate": "2026",
    "sername": null,
    "series_name": null,
    "issue": "DOI:10.5066\/P1XVJEZG",
    "publish": null,
    "publisher_name": null,
    "onlink": "https:\/\/cmgds.marine.usgs.gov\/catalog\/whcmsc\/SB_data_release\/DR_P1XVJEZG\/Meta_AL21_cores.faq.html",
    "format": null,
    "email": null,
    "descript": "To assess historical environment changes associated with changes in hydrologic connection to the Gulf Intracoastal Waterway (GIW) and Mobile Bay, six sediment cores (50-80 cm in length) were collected in 2021 from two coastal wetland sites. These two sites in Gulf Shores, Alabama were: Oyster Bay Nature Preserve (\"OB\", a brackish marsh with natural hydrology) and the Emmet O. and Vina Wenzel Wetland Preserve (\"WW\", an impounded coastal wetland). The OB control site is a 1.5 square kilometer wetland with unobstructed natural oscillations in water levels and continuous connection to the GIW and Mobile Bay. The WW impounded study site is approximately 1.9 square kilometers; it has been cut off from saltwater exchange by three events. First, construction of the GIW in 1937 created berms of dredge spoils along the southern border. Second, culverts installed during completion of County Road 4 in the 1970s sharply reduced exchange between the wetland and the GIW.  Third, Hurricane Ivan (2004) dropped a barge on the wetland; after several years, it was removed by dragging across the wetland and County Road 4 into the GIW. This sharply altered the geomorphology of the eastern section of the wetland located north of County Road 4. These three events have led to a nearly complete occlusion of the WW wetland from the GIW and Mobile Bay. As a result, the WW wetland does not experience tidal exchange and is continuously flooded due to retention of surface water from surrounding uplands. Transects were established, at both sites, starting from the tidal creek at OB and from the former tidal inlet at WW and moving toward the marsh interior. Cores were collected from three sites along each transect; core sections were age-dated using radioisotopes, and analyzed for carbon, nitrogen, and sulfur content and stable isotopes. Age-models were constructed from lead-210 in five of the six cores; the OB3 core (collected furthest from the tidal creek) was not dateable because the excess lead-210 profile was disturbed down to 20 centimeters. Accretion rates at OB were similar across the two dateable sites (OB1 and OB2) and through time with an average of 2.7 +\/- 1.0 millimeters per year. Vertical accretion rates have increased with time across the WW sites, with the highest rates (6.0 +\/- 1.2 millimeters per year) observed at WW2 (midway along the transect) since near total impoundment in 2008. Carbon accretion rates at OB1 and OB2 have remained similar through the past century at 65 +\/- 28 grams Carbon per square meter per year. Prior to impoundment, accretion rates at WW were lower (38 +\/- 24 grams Carbon per square meter per year) than OB. Since impoundment, carbon storage rates at WW have reached 132 +\/- 60 grams Carbon per square meter per year.",
    "lang": null,
    "journal": null,
    "pwid": null,
    "originator": [
        {
            "name": "O'Keefe Suttles, Jennifer A.",
            "role": "Author"
        },
        {
            "name": "Eagle, Meagan J.",
            "role": "Author"
        },
        {
            "name": "Shannon Valley",
            "role": "Author"
        }
    ],
    "index_term": [
        {
            "thcode": 2,
            "code": "1420",
            "name": "carbon",
            "scope": "Nonmetal element with symbol C and atomic number 6 <http:\/\/periodic.lanl.gov\/6.shtml>"
        },
        {
            "thcode": 2,
            "code": "142",
            "name": "carbon isotope analysis",
            "scope": "Experimental determination of the proportion of a given stable carbon isotope (C12 or C13) in a sample."
        },
        {
            "thcode": 2,
            "code": "1799",
            "name": "coastal processes",
            "scope": "Processes unique to coastal areas including longshore transport, beach erosion, storm surge, shoreline change, delta formation, barrier island migration, beach stabilization by vegetation"
        },
        {
            "thcode": 2,
            "code": "310",
            "name": "ecological processes",
            "scope": "Dynamic biogeochemical interactions that occur among and between biotic and abiotic components of the biosphere."
        },
        {
            "thcode": 2,
            "code": "1522",
            "name": "nitrogen",
            "scope": "Nonmetal element with symbol N and atomic number 7 <http:\/\/periodic.lanl.gov\/7.shtml>"
        },
        {
            "thcode": 2,
            "code": "2062",
            "name": "piston coring",
            "scope": "Use of a piston mechanism and a weight with a triggering mechanism to drive a coring tube deep into underwater sediments for extraction and study."
        },
        {
            "thcode": 2,
            "code": "911",
            "name": "plot sampling",
            "scope": "Outlining small areas of land within a larger area to use as samples to study biological populations or ecosystems."
        },
        {
            "thcode": 2,
            "code": "954",
            "name": "radiometric dating",
            "scope": "Methods for age determination of rocks and fossils by measuring the proportions of naturally occurring radioactive isotopes to their decay products."
        },
        {
            "thcode": 2,
            "code": "1028",
            "name": "sea-level change",
            "scope": "Variation in the relative vertical position of land and ocean waters. Caused globally by changes in the distribution of ice masses and the shape of the oceans, and locally by the rate of uplift or subsidence of the land surface.  Includes both global (eustatic) and local (relative) sea-level variations."
        },
        {
            "thcode": 2,
            "code": "1036",
            "name": "sedimentation",
            "scope": "Process of deposition of sediments (loose, uncemented pieces of rock, mineral fragments, or biological materials).  The sediments settle out of water or air into layers on a surface."
        },
        {
            "thcode": 2,
            "code": "1078",
            "name": "soil chemistry",
            "scope": "Branch of chemistry concerned with the elements and compounds that make up soils. Includes chemical processes involving soils."
        },
        {
            "thcode": 2,
            "code": "1582",
            "name": "sulfur",
            "scope": "Nonmetal element with symbol S and atomic number 16 <http:\/\/periodic.lanl.gov\/16.shtml>"
        },
        {
            "thcode": 2,
            "code": "1326",
            "name": "wetland ecosystems",
            "scope": "Ecosystems whose soil is saturated for long periods seasonally or continuously, including marshes, swamps, and ephemeral ponds.  More detailed terms for wetlands can be selected from the FGDC Wetland Classification <http:\/\/fgdc.gov\/standards\/status\/sub3_4.html>."
        },
        {
            "thcode": 2,
            "code": "1327",
            "name": "wetland functions",
            "scope": "Processes related to wetlands such as support of ecosystems, evaporation effects on weather, nutrient cycles, etc."
        },
        {
            "thcode": 15,
            "code": "002",
            "name": "biota",
            "scope": "Flora or fauna in natural environment, for example wildlife, vegetation, biological sciences, ecology, wilderness, sea life, wetlands, habitat, biological resources"
        },
        {
            "thcode": 15,
            "code": "006",
            "name": "elevation",
            "scope": "Height above or below sea level, for example altitude, bathymetry, digital elevation models, slope, derived products, DEMs, TINs"
        },
        {
            "thcode": 15,
            "code": "007",
            "name": "environment",
            "scope": "Environmental resources, protection and conservation, for example environmental pollution, waste storage and treatment, environmental impact assessment, monitoring environmental risk, nature reserves, landscape, water quality, air quality, environmental modeling"
        },
        {
            "thcode": 15,
            "code": "008",
            "name": "geoscientificInformation",
            "scope": "Information pertaining to earth sciences, for example geophysical features and processes, geology, minerals, sciences dealing with the composition, structure and origin of the earth's rocks, risks of earthquakes, volcanic activity, landslides, gravity information, soils, permafrost, hydrogeology, groundwater, erosion"
        },
        {
            "thcode": 15,
            "code": "012",
            "name": "inlandWaters",
            "scope": "Inland water features, drainage systems and characteristics, for example rivers and glaciers, salt lakes, water utilization plans, dams, currents, floods and flood hazards, water quality, hydrographic charts, watersheds, wetlands, hydrography"
        },
        {
            "thcode": 15,
            "code": "013",
            "name": "location",
            "scope": "Positional information and services, for example addresses, geodetic networks, geodetic control points, postal zones and services, place names, geographic names"
        },
        {
            "thcode": 15,
            "code": "014",
            "name": "oceans",
            "scope": "Features and characteristics of salt water bodies (excluding inland waters), for example tides, tidal waves, coastal information, reefs, maritime, outer continental shelf submerged lands, shoreline"
        }
    ],
    "place_term": [],
    "image": [
        {
            "name": "https:\/\/www.sciencebase.gov\/catalog\/file\/get\/69c14714b66b01d4f71ecb05?name=ImpoundedWetland_WestWenzel.JPG",
            "description": "Browse graphic is a photograph of the impounded study site, Wenzel Wetland in Gulf Shores, Alabama."
        }
    ],
    "fan": [
        "2021-034-FA"
    ]
}