Collection, analysis, and age-dating of sediment cores from mangrove wetlands in San Juan Bay Estuary, Puerto Rico, 2016

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Frequently anticipated questions:

What does this data set describe?

Title:
Collection, analysis, and age-dating of sediment cores from mangrove wetlands in San Juan Bay Estuary, Puerto Rico, 2016
Abstract:
The San Juan Bay Estuary, Puerto Rico, contains mangrove forests that store significant amounts of organic carbon in soils and biomass. There is a strong urbanization gradient across the estuary, from the highly urbanized and clogged Caño Martin Peña in the western part of the estuary, a series of lagoons in the center of the estuary, and a tropical forest reserve (Piñones) in the easternmost part with limited urbanization. We collected sediment cores to determine carbon burial rates and vertical sediment accretion from five sites in the San Juan Bay Estuary. Cores were radiometrically-dated using lead-210 and the Plum age model. Sites had soil C burial rates ranging from 50 grams per meter squared per year (g m-2 y-1) in the San José lagoon to 632 g m-2 y-1 in the Caño Martin Peña in recent decades. Soil accretion and carbon burial rates were greater in recent decades (1970-2016) compared to historic decades (1930-1970) at some of the forest mangrove sites (i.e. Caño Martin Peña). Apparently, not only urbanization, but site-specific flushing patterns, landscape setting, and soil characteristics affected soil C burial rates. This dataset can help evaluate how differences in urbanization (low in the forest preserve to high in the clogged canal), flushing, and landscape setting influence soil accretion and carbon burial in urban, tropical mangrove forests.
  1. How might this data set be cited?
    Eagle, Meagan J., Wigand, Cathleen, Branoff, Benjamin, Balogh, Stephen, Miller, Kenneth M., Martin, Rose M., Hanson, Alana, Oczkowski, Autumn J., Huerta, Evelyn, Loffredo, Joseph, Watson, Elizabeth B., and Jennifer A. O'Keefe Suttles, 20210630, Collection, analysis, and age-dating of sediment cores from mangrove wetlands in San Juan Bay Estuary, Puerto Rico, 2016: data release DOI:10.5066/P97CAF30, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Eagle, M.J., Wigand, C., Branoff, B., Balogh, S., Miller, K.M., Martin, R.M., Hanson, A., Oczkowski, A.J., Huertas, E., Loffredo, J., Watson, E.B., and O'Keefe Suttles, J.A., 2021, Collection, analysis, and age-dating of sediment cores from mangrove wetlands, San Juan Bay estuary Puerto Rico, 2016: U.S. Geological Survey data release, https://doi.org/10.5066/P97CAF30.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -66.05859
    East_Bounding_Coordinate: -65.95644
    North_Bounding_Coordinate: 18.44027
    South_Bounding_Coordinate: 18.42839
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/60902e3fd34e93746a710491?name=PR_mangrove_coring.png (PNG)
    Browse graphic is a photograph of study collaborators collecting a sediment core in a mangrove, Puerto Rico.
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 03-Mar-2016
    Currentness_Reference:
    Ground Condition. These are the dates when the cores were collected.
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: tabulated comma-separated values file (*.csv).
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 1.0E-5. Longitudes are given to the nearest 1.0E-5. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.
  7. How does the data set describe geographic features?
    Data_PR_Cores.csv
    Comma separated text file (*csv) and Microsoft Excel file (.xlsx) with soil core data collected from five mangrove sites along an urbanization gradient in San Juan, Puerto Rico. Mirosoft Excel versions of each entitiy are provided for users to verify proper text formatting that may not be preserved when opening the CSV UTF-8 files in certain editors. The file includes latitude and longitude of core collection, calculated values of soil dry bulk density, radionuclide data from gamma spectroscopy, soil carbon and nitrogen content, carbon-13 and nitrogen-15 data for select core sections. The dataset includes 184 records. (Source: Producer-defined)
    Site
    A text identifier for the general location of the study site. Note that multiple cores were collected from the same site. Refer to the attributes "Replicate" and "ID" for specific core details. (Source: Producer-defined)
    ValueDefinition
    Martin Peña WestA data point from a sediment core collected from a mangrove wetland in a dredged canal along the west end of the Caño de Martín Peña. Relative flushing at this site is medium to high.
    Martin Peña EastA data point from a sediment core collected from a mangrove wetland in a clogged canal along the east end of the Caño de Martín Peña, toward the Laguna San José. Relative flushing at this site is low.
    Torrecilla LagoonA data point from a sediment core collected from a mangrove wetland in the Torrecilla Lagoon. Relative flushing at this site is medium to high.
    San José LagoonA data point from a sediment core collected from a mangrove wetland in the José Lagoon. Relative flushing at this site is medium.
    PiñonesA data point from a sediment core collected from a mangrove wetland within the Piñones Forested Reserve. Relative flushing at this site is low.
    Replicate
    A numerical identifier indicating from which duplicate core the data is reported. (Source: Producer-defined)
    ValueDefinition
    OneData point collected from a replicate core number 1.
    TwoData point collected from replicate core number 2.
    ID
    Abbreviated alphabetical identification code of each core to indicate: 1) the study site from which it was collected using a two or three letter abbreviation; and 2) a number 1 or 2 to indicate the replicate core number from which the data is reported. (Source: Producer-defined)
    ValueDefinition
    MPW1Martin Peña West, core 1.
    MPE1Martin Peña East, core 1.
    MPE2Martin Peña East, core 2.
    TORR1Torrecilla, core 1.
    TORR2Torrecilla, core 2.
    SJ1San José, core 1.
    SJ2San José, core 2.
    PIN1Piñones, core 1.
    PIN2Piñones, core 2.
    Date
    A numeric identifier of the date the core was collected in the format of month/day/year. (Source: Producer defined)
    Range of values
    Minimum:03/03/2016
    Maximum:03/06/20106
    Units:mm/dd/yyyy
    Lat
    Latitude decimal degrees north, NAD83 (Source: Producer-defined)
    Range of values
    Minimum:18.42839
    Maximum:18.44027
    Units:decimal degrees
    Lon
    Longitude decimal degrees west, NAD83. The negative value indicates a location in the western hemisphere. (Source: Producer-defined)
    Range of values
    Minimum:-66.05859
    Maximum:-65.95644
    Units:decimal degrees
    Depth_min
    A numeric identifier of the interval minimum depth below the sediment interface in centimeters. (Source: Producer-defined)
    Range of values
    Minimum:0
    Maximum:49
    Units:centimeters
    Depth_max
    A numeric identifier of the interval maximum depth below the sediment interface in centimeters. (Source: Producer-defined)
    Range of values
    Minimum:1.0
    Maximum:51.0
    Units:centimeters
    Depth_mid
    A numeric identifier of the interval mid-point depth below the sediment interface in centimeters. (Source: Producer-defined)
    Range of values
    Minimum:0.5
    Maximum:50.0
    Units:centimeters
    DBD
    Dry Bulk Density: A numeric identifier of the sediment dry bulk density in grams per cubic centimeter (g/cm3). Blank/empty cells indicate the measurement was not done. (Source: Producer-defined)
    Range of values
    Minimum:0.0587
    Maximum:2.3570
    Units:grams per cubic centimeter
    210Pb
    A numeric identifier of the sediment total lead-210 activity in decays per minute per gram (dpm/g). Measured at 46.5 kiloelectron volts (KeV) on a planar gamma counter. Blank/empty cells indicate the measurement was not done. (Source: Producer-defined)
    Range of values
    Minimum:0.0892
    Maximum:18.1456
    Units:decays per minute per gram
    210Pb_e
    A numeric identifier of the measurement error in sediment total lead-210 activity in decays per minute per gram (dpm/g). Blank/empty cells indicate the measurement was not done. The value 0.00 is given to analyzed samples found to be below detection. (Source: Producer-defined)
    Range of values
    Minimum:0.0205
    Maximum:1.5671
    Units:decays per minute per gram
    226Ra
    A numeric identifier of the sediment total radium-226 activity in decays per minute per gram (dpm/g). Measured at 352 kiloelectron volts (KeV) on a planar gamma counter. Blank/empty cells indicate the measurement was not done. The value 0.00 is given to analyzed samples found to be below detection. (Source: Producer-defined)
    Range of values
    Minimum:0.0509
    Maximum:10.9070
    Units:decays per minute per gram
    226Ra_e
    A numeric identifier of the measurement error in sediment total radium-226 activity in decays per minute per gram (dpm/g). Blank/empty cells indicate the measurement was not done. The value 0.00 is given to analyzed samples found to be below detection. (Source: Producer-defined)
    Range of values
    Minimum:0.0021
    Maximum:0.8606
    Units:decays per minute per gram
    210Pbex
    A numeric identifier of the sediment excess lead-210 activity in decays per minute per gram (dpm/g), decay-corrected to date of core collection. Calculated as the difference between total lead-210 and total radium-226 activities. Blank/empty cells indicate the measurement was not done. (Source: Producer-defined)
    Range of values
    Minimum:-3.4577
    Maximum:16.5907
    Units:decays per minute per gram
    210Pbex_e
    A numeric identifier of the propagated measurement error in sediment excess lead-210 activity in decays per minute per gram (dpm/g), decay-corrected to date of core collection. Blank/empty cells indicate the measurement was not done. (Source: Producer-defined)
    Range of values
    Minimum:0.0206
    Maximum:1.8000
    Units:decays per minute per gram
    137Cs
    A numeric identifier of the sediment total cesium-137 activity in decays per minute per gram (dpm/g), decay-corrected to date of core collection. Measured at 662 kiloelectron volts (KeV) on a planar gamma counter. Blank/empty cells indicate the measurement was not done. The value 0.00 is given to analyzed samples found to be below detection. (Source: Producer-defined)
    Range of values
    Minimum:0.0825
    Maximum:1.0983
    Units:decays per minute per gram
    137Cs_e
    A numeric identifier of the measurement error in sediment total cesium-137 activity in decays per minute per gram (dpm/g), decay-corrected to date of core collection. Blank/empty cells indicate the measurement was not done. The value 0.00 is given to analyzed samples found to be below detection. (Source: Producer-defined)
    Range of values
    Minimum:0.0048
    Maximum:0.0993
    Units:decays per minute per gram
    7Be
    A numeric identifier of the measurement error in sediment total beryllium-7 activity in decays per minute per gram (dpm/g), decay-corrected to date of core collection. Measured at 477 kiloelectron volts (KeV) on a planar gamma counter. Blank/empty cells indicate the measurement was not done. The value 0.00 is given to analyzed samples found to be below detection. (Source: Producer-defined)
    Range of values
    Minimum:0.0000
    Maximum:0.0000
    Units:decays per minute per gram
    7Be_e
    A numeric identifier of the measurement error in sediment total beryllium-7 activity in decays per minute per gram (dpm/g), decay-corrected to date of core collection. Blank/empty cells indicate the measurement was not done. The value 0.00 is given to analyzed samples found to be below detection. (Source: Producer-defined)
    Range of values
    Minimum:0.0000
    Maximum:0.0000
    Units:decays per minute per gram
    wtC
    Total amount of organic carbon by weight percent in soil. Sediments in this sample set were placed in an acid fuming desiccator to remove inorganic carbon prior to analysis. Blank/empty cells indicate the measurement was not done. Refer to the attribute accuracy and process step sections for further details. (Source: Producer-defined)
    Range of values
    Minimum:1.1033
    Maximum:35.5859
    Units:unitless
    wtN
    Total amount of organic nitrogen by weight percent in soil. Sediments in this sample set were placed in a acid fuming desicator to remove inorganics prior to analysis. Blank/empty cells indicate the measurement was not done. Refer to the attribute accuracy and process step sections for further details. (Source: Producer-defined)
    Range of values
    Minimum:0.0722
    Maximum:2.2809
    Units:unitless
    13C
    The carbon isotopic signature of the soil sample relative to Pee Dee Belemnite (PDB) standard. Blank/empty cells indicate the measurement was not done. (Source: Producer-defined)
    Range of values
    Minimum:-29.2365
    Maximum:-23.8330
    Units:parts per thousand OR per mil
    15N
    The nitrogen isotopic signature of the soil sample relative to air. Blank/empty cells indicate the measurement was not done. (Source: Producer-defined)
    Range of values
    Minimum:2.3182
    Maximum:7.6890
    Units:parts per thousand OR per mil
    Data_PR_AgeModel.csv
    Comma separated text file (*csv) and Microsoft Excel file (.xlsx) with soil core modeled age depth data from five mangrove sites along an urbanization gradient in San Juan, Puerto Rico. Mirosoft Excel versions of each entitiy are provided for users to verify proper text formatting that may not be preserved when opening the CSV UTF-8 files in certain editors. The file includes latitude and longitude of core collection and modeled mass accumulation rates, vertical accretion rates, carbon accretion rates and nitrogen accretion rates based on lead-210 derived Plum sediment age-models. Vertical accretion rates were obtained from each chronology using the “accrate depth” function in Plum at 1 cm depth intervals. Data required for those calculations (radionuclides, DBD, wtC, wtN) as well as carbon and nitrogen isotope ratios (13C, 15N) are reported in an additional entity provided with this data release. Note that actual cores were sectioned at 1 cm or 2 cm intervals, with finer sections near the sediment surface and coarser sectioning at depth. The age-model was run at 1 cm intervals for the entire core, with the modeled mass, carbon and nitrogen accretion rates based on analysis of parameters from 2 cm sediment sections. DBD, wtC and wtN were only matched to one modeled core interval per measurement, so blank values occur. For example, sediment properties were measured on the 10-12 cm interval, and matched with model results from 10-11 cm, with no sediment properties matched to 11-12 cm. The dataset includes 323 records. (Source: Producer-defined)
    Site
    A text identifier for the general location of the study site. Note that multiple cores were collected from the same site. Refer to the attributes "Replicate" and "ID" for specific core details. (Source: Producer-defined)
    ValueDefinition
    Martin Peña WestA data point from a sediment core collected from a mangrove wetland in a dredged canal along the west end of the Caño de Martín Peña. Relative flushing at this site is medium to high.
    Martin Peña EastA data point from a sediment core collected from a mangrove wetland in a clogged canal along the east end of the Caño de Martín Peña, toward the Laguna San José. Relative flushing at this site is low.
    Torrecilla LagoonA data point from a sediment core collected from a mangrove wetland in the Torrecilla Lagoon. Relative flushing at this site is medium to high.
    San José LagoonA data point from a sediment core collected from a mangrove wetland in the José Lagoon. Relative flushing at this site is medium.
    PiñonesA data point from a sediment core collected from a mangrove wetland within the Piñones Forested Reserve. Relative flushing at this site is low.
    Replicate
    A numerical identifier indicating from which duplicate core the data is reported. (Source: Producer-defined)
    ValueDefinition
    OneData point collected from a replicate core number 1.
    TwoData point collected from replicate core number 2.
    ID
    Abbreviated alphabetical identification code of each core to indicate: 1) the study site from which it was collected using a two or three letter abbreviation; and 2) a number 1 or 2 to indicate the replicate core number from which the data is reported. (Source: Producer-defined)
    ValueDefinition
    MPW1Martin Peña West core 1.
    MPE1Martin Peña East, core 1.
    MPE2Martin Peña East, core 2.
    TORR1Torrecilla, core 1.
    TORR2Torrecilla, core 2.
    SJ1San José, core 1.
    SJ2San José, core 2.
    PIN1Piñones, core 1.
    PIN2Piñones, core 2.
    Date
    A numeric identifier of the date the core was collected in the format of month/day/year. (Source: Producer defined)
    Range of values
    Minimum:03/03/2016
    Maximum:03/06/20106
    Units:mm/dd/yyyy
    Lat
    Latitude decimal degrees north, NAD83 (Source: Producer-defined)
    Range of values
    Minimum:18.42839
    Maximum:18.44027
    Units:decimal degrees
    Lon
    Longitude decimal degrees west, NAD83. The negative value indicates a location in the western hemisphere. (Source: Producer-defined)
    Range of values
    Minimum:-66.05859
    Maximum:-65.95644
    Units:decimal degrees
    Depth_min
    A numeric identifier of the interval minimum depth below the sediment interface in centimeters. (Source: Producer-defined)
    Range of values
    Minimum:0
    Maximum:49
    Units:centimeters
    Depth_max
    A numeric identifier of the interval maximum depth below the sediment interface in centimeters. (Source: Producer-defined)
    Range of values
    Minimum:1
    Maximum:50
    Units:centimeters
    VAR_LL
    Vertical Accretion Rate at the lower limit of the 95% confidence interval. A numeric identifier for the vertical accretion rate of the sediment in millimeters per year (mm/y). Accretion rates were obtained from each chronology using the “accrate depth” function in Plum at 1 cm depth intervals. (Source: Producer-defined)
    Range of values
    Minimum:0.3
    Maximum:7.2
    Units:millimeters per year
    VAR_50
    Mean Vertical Accretion Rate. A numeric identifier for the vertical accretion rate of the sediment in millimeters per year (mm/y). Accretion rates were obtained from each chronology using the “accrate depth” function in Plum at 1 cm depth intervals.. (Source: Producer-defined)
    Range of values
    Minimum:0.62
    Maximum:13.68
    Units:millimeters per year
    VAR_UL
    Vertical Accretion Rate at the upper limit of the 95% confidence interval. A numeric identifier for the vertical accretion rate of the sediment in millimeters per year (mm/y). Accretion rates were obtained from each chronology using the “accrate depth” function in Plum at 1 cm depth intervals. (Source: Producer-defined)
    Range of values
    Minimum:1.43
    Maximum:26.07
    Units:millimeters per year
    MAR_LL
    Mass Accumulation Rate at the lower limit of the 95% confidence interval. A numeric identifier for the mass accumulation rate of the sediment in grams per square meter per year (g/m2/y). Calculated by multiplying dry bulk density times vertical accretion rate. Refer to the entity description for an explanation of blank cells. (Source: Producer-defined)
    Range of values
    Minimum:46
    Maximum:3710
    Units:grams sediment per square meter per year
    MAR_50
    Mean Mass Accumulation Rate. A numeric identifier for the mass accumulation rate of the sediment in grams per square meter per year (g/m2/y). Calculated by multiplying dry bulk density times vertical accretion rate. Refer to the entity description for an explanation of blank cells. (Source: Producer-defined)
    Range of values
    Minimum:82
    Maximum:8635
    Units:grams sediment per square meter per year
    MAR_UL
    Mass Accumulation Rate at the upper limit of the 95% confidence interval. A numeric identifier for the mass accumulation rate of the sediment in grams per square meter per year (g/m2/y). Calculated by multiplying dry bulk density times vertical accretion rate. Refer to the entity description for an explanation of blank cells. (Source: Producer-defined)
    Range of values
    Minimum:147
    Maximum:27036
    Units:grams sediment per square meter per year
    CAR_LL
    Carbon Accumulation Rate at the lower limit of the 95% confidence interval. A numeric identifier for the carbon mass accumulation rate of the sediment in grams of carbon per square meter per year (gC/m2/y). Calculated by multiplying the average mass accumulation rates for the combined depth interval of the elemental sample times weight percent carbon. Refer to the entity description for an explanation of blank cells. (Source: Producer-defined)
    Range of values
    Minimum:5.84
    Maximum:606.98
    Units:grams carbon per square meter per year
    CAR_50
    Mean Carbon Accumulation Rate. A numeric identifier for the carbon mass accumulation rate of the sediment in grams of carbon per square meter per year (gC/m2/y). Calculated by multiplying the average mass accumulation rates for the combined depth interval of the elemental sample times weight percent carbon. Refer to the entity description for an explanation of blank cells. (Source: Producer-defined)
    Range of values
    Minimum:12.1
    Maximum:1108.63
    Units:grams carbon per square meter per year
    CAR_UL
    Carbon Accumulation Rate at the upper limit of the 95% confidence interval. A numeric identifier for the carbon mass accumulation rate of the sediment in grams of carbon per square meter per year (gC/m2/y). Calculated by multiplying the average mass accumulation rates for the combined depth interval of the elemental sample times weight percent carbon. Refer to the entity description for an explanation of blank cells. (Source: Producer-defined)
    Range of values
    Minimum:31.3
    Maximum:2356.17
    Units:grams carbon per square meter per year
    NAR_LL
    Nitrogen Accumulation Rate at the lower limit of the 95% confidence interval. A numeric identifier for the nitrogen mass accumulation rate of the sediment in grams of nitrogen per square meter per year (g N/m2/y). Calculated by multiplying the average mass accumulation rates for the combined depth interval of the elemental sample times weight percent nitrogen. Refer to the entity description for an explanation of blank cells. (Source: Producer-defined)
    Range of values
    Minimum:0.47
    Maximum:34.52
    Units:grams nitrogen per square meter per year
    NAR_50
    Mean Nitrogen Accumulation Rate. A numeric identifier for the nitrogen mass accumulation rate of the sediment in grams of nitrogen per square meter per year (g N/m2/y). Calculated by multiplying the average mass accumulation rates for the combined depth interval of the elemental sample times weight percent nitrogen. Refer to the entity description for an explanation of blank cells. (Source: Producer-defined)
    Range of values
    Minimum:0.86
    Maximum:68.51
    Units:grams nitrogen per square meter per year
    NAR_UL
    Nitrogen Accumulation Rate at the upper limit of the 95% confidence interval. A numeric identifier for the nitrogen mass accumulation rate of the sediment in grams of nitrogen per square meter per year (g N/m2/y). Calculated by multiplying the average mass accumulation rates for the combined depth interval of the elemental sample times weight percent nitrogen. Refer to the entity description for an explanation of blank cells. (Source: Producer-defined)
    Range of values
    Minimum:1.56
    Maximum:181.85
    Units:grams nitrogen per square meter per year
    Year_LL
    The year corresponding to the soil horizon at the lower limit of the 95% confidence interval based on the age-depth models generated by radiometric dating and Plum models. Calculated as collection date minus age of sediment at each depth interval. (Source: Producer-defined.)
    Range of values
    Minimum:1814
    Maximum:2016
    Units:calendar year
    Year_50
    Mean of the year corresponding to the soil horizon based on the age-depth models generated by radiometric dating and Plum models. Calculated as collection date minus age of sediment at each depth interval. (Source: Producer-defined.)
    Range of values
    Minimum:1842
    Maximum:2016
    Units:calendar year
    Year_UL
    The year corresponding to the soil horizon at the upper limit of the confidence interval, 97.5th percentile based on the age-depth models generated by radiometric dating and Plum models. Calculated as collection date minus age of sediment at each depth interval. (Source: Producer-defined.)
    Range of values
    Minimum:1875
    Maximum:2016
    Units:calendar year

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Meagan J. Eagle
    • Cathleen Wigand
    • Benjamin Branoff
    • Stephen Balogh
    • Kenneth M. Miller
    • Rose M. Martin
    • Alana Hanson
    • Autumn J. Oczkowski
    • Evelyn Huerta
    • Joseph Loffredo
    • Elizabeth B. Watson
    • Jennifer A. O'Keefe Suttles
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Meagan J Eagle
    Northeast Region: WOODS HOLE COASTAL and MARINE SCIENCE CENTER
    Research Physical Scientist
    384 Woods Hole Road
    Woods Hole, MA
    US

    508-548-8700 x2280 (voice)
    meagle@usgs.gov

Why was the data set created?

Sediment cores were collected, age-dated, and their carbon and nitrogen content were measured to calculate vertical accretion and carbon and nitrogen burial rates. Data were collected to evaluate how urban influence and hydrology impact accretion in mangrove forests.

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: 2016 (process 1 of 4)
    Five mangrove sites along an urbanization gradient in the San Juan Bay Estuary, Puerto Rico were selected for this study. Sites included the highly urbanized and clogged Caño Martin Peña in the western part of the estuary, a series of lagoons in the center of the estuary, and a tropical forest reserve (Piñones) in the eastern-most part. Mangrove sediment cores, two from each site, about 1 m apart, were collected in March 2016 in the Martin Peña West (MPW), Martin Peña East (MPE), San José Lagoon (SJ), Torrecilla Lagoon (Torr), and Piñones forest (Pin) with a Russian peat sampler to a maximum depth of 50 cm depending upon ability to penetrate coarse mangrove rhizomes. Core depths ranged from 37 – 50 cm. Cores were first covered in saran wrap, then aluminum foil, and then secured with duct tape in a PVC holder for stabilization and transport to the lab. Samples were placed in coolers and shipped to the US mainland via FedEx overnight air transport. Cores were shipped to the USEPA Environmental Effects Research Laboratory, Atlantic Ecology Division in Narragansett, RI. Upon arrival at the lab, the cores were put into the freezer (-18C) until processed.
    One core collected from MPW was damaged during air transport to the US mainland and was not radiometrically dated. The other nine cores were sliced in one cm increments at the surface (0 - 3 cm) and then every 2 cm to the bottom of the core (unless otherwise indicated). After slicing, the subsamples were dried in pre-weighed aluminum tins (see subsequent processing steps below). Soil subsamples were used for radiometric dating, stable isotope, percent C, dry bulk density (DBD), and sediment accretion analyses as described below. However, only one of the two replicates from the San José lagoon was processed for DBD due to human error, so DBD values from one SJ core were used in calculations of C storage and sequestration for both replicates from that site. Person who carried out this activity:
    Cathleen Wigand
    USEPA Environmental Effects Research Laboratory
    Research Physical Scientist
    27 Tarzwell Drive
    Narragansett, RI
    US

    401-782-3090 (voice)
    Wigand.cathleen@Epa.gov
    Date: 2018 (process 2 of 4)
    Sliced subsamples were measured (length, width, and height) and then dried at 60°C for at least 48 hours. The soils were not sieved so the peat included live and decomposing roots. The dried soils were used to determine dry bulk density (gram dry weight divided by volume; g ml-1). A subsample of the dried soil was ground to a fine powder using a mortar and pestle. The dried, ground material was used for stable isotope (C,N) and percent C and N analyses. To remove carbonates, subsamples to be used for %C and C isotope analyses were fumigated prior to analyses with 12 M HCl following the method of Harris and others, 2001. Subsamples for %N and N isotope analyses were not fumigated. The C and N isotope compositions were determined using an Elementar Vario Micro elemental analyzer connected to a continuous flow Isoprime 100 isotope ratio mass spectrometer (IRMS) (Elementar Americas, Mt. Laurel, NJ). Replicate analyses of isotopic standard reference materials USGS 40 (δ13C = -26.39 ‰; δ15N = -4.52 ‰) and USGS 41 (δ13C = 37.63 ‰; δ15N = 47.57 ‰) were used to normalize isotopic values of working standards to the air (δ15N) and Vienna Pee Dee Belemnite (δ13C) scales (Paul and others, 2007). Stable isotope values are expressed in sigma (δ) notation following the formula δX (‰) = [(Rsample / Rstandard) – 1] × 103, where X is the less common isotope and R is ratio of the less common to more common isotope [13C/12C or 15N/14N]. Working standards were analyzed after every 24 samples to monitor instrument performance and check data normalization. The precision of the laboratory standards was better than ± 0.3‰ for δ13C and δ15N. The %C and %N were calculated by comparing the peak area of the unknown sample to a standard curve of peak area versus the C or N content of a known standard.
    Harris, D., Horwarth, W.R., and van Kessel, C., 2001, Acid fumigation of soils to remove carbonates prior to total organic carbon or carbon-13 isotopic analysis: Soil Sci. Soc. Am. J. 65:1853–6.
    Paul, D., Skrzypek, G. and Fórizs, I., 2007, Normalization of measured stable isotopic compositions to isotope reference scales – A review: Rapid Communications in Mass Spectrometry 21 (18): 3006–3014. Person who carried out this activity:
    Cathleen Wigand
    USEPA Environmental Effects Research Laboratory
    Research Physical Scientist
    27 Tarzwell Drive
    Narragansett, RI
    US

    401-782-3090 (voice)
    Wigand.cathleen@Epa.gov
    Date: 2018 (process 3 of 4)
    Gamma analysis was performed on 10 to 20 samples that spanned each sediment core. One to ten grams of homogenized sediment were sealed for 3 weeks and counted on a planar-type gamma counter for 24 to 48 hours to measure 137Cs, 210Pb, and 226Ra at 661.6, 46.5 and 352 KeV energies respectively (Canberra Inc. USA). Activities of 137Cs and 210Pb were decay corrected to time of collection; suppression of low energy peaks by self-absorption was corrected according to Cutshall and others, 1983. Age models were developed using Plum (Aquino-López and others, 2018; Blaauw and others, 2020) version 0.1.4 in R version 4.0.0 (R Core Team 2020). Plum is an age-depth model that utilizes 210Pb and is based on the same Bayesian chronology statistical treatment as Bacon, a widely used model with 14C ages (Blaauw and Christen 2011). Plum uses distributions of prior environmental parameters that impact the 210Pb profile, including 210Pb deposition rates, supported 210Pb (i.e., 226Ra) and accretion rates, with posterior distributions providing realistic uncertainty estimates. A major benefit of Plum over the commonly used analytical solution to the continuous rate of supply model (Appleby and Oldfield 1978) is that chronologies can be calculated even if radioisotopes have not been analyzed for the entire core. Furthermore, this model yields more than one accretion rate estimate, unlike the constant initial concentration model (Goldberg, 1963) which is normally used for cores with discontinuous 210PB profiles. Total 210Pb data were input into Plum, with supported 210Pb (i.e., 226Ra) estimated within the model framework from the deepest samples. We broadened the priors from default settings within Plum. We simulated means (50%) and the lower (6%) and upper confidence limits (94%) for each 1 cm depth in the sediment cores. We report means and 88% confidence intervals in the age-depth profiles for each core. Sediment accretion rates (SAR) were obtained from each chronology using the “accrate depth” function in Plum at 1 cm depth intervals.
    Cutshall, N.H., Larsen, I.L., and Olsen, C.R., 1983, Direct analysis of 210 Pb in sediment samples—Self-absorption corrections: Nuclear Instruments and Methods in Physics Research, v. 206, issues 1–2, p. 309–312, https://doi.org/10.1016/0167-5087(83)91273-5.
    Aquino-López, M.A., Blaauw, M., Christen, J.A., and Sanderson, N.K., 2018, Bayesian analysis of 210 Pb dating: Journal of Agricultural, Biological and Environmental Statistics, v. 23, p. 317–333, https://doi.org/10.1007/s13253-018-0328-7.
    Blaauw, M., Christen, J.A., Aquino-López, M.A., Esquivel-Vazquez, J., Gonzalez V., O.M., Belding, T., Theiler, J., Gough, B. and Karney, C., 2020, rplum: Bayesian Age-Depth Modelling of Cores Dated by Pb-210. R package version 0.1.4. https://cran.r-project.org/web/packages/rplum/index.html.
    Blaauw, M., and Christen, J.A., 2011. Flexible paleoclimate age-depth models using an autoregressive gamma process: Bayesian Analysis, v. 6, p. 457–474, https://doi.org/10.1214/11-BA618.
    Appleby, P.G., and Oldfield, F., 1978, The calculation of lead-210 dates assuming a constant rate of supply of unsupported 210Pb to the sediment: Catena, v. 5, issue 1, p. 1–8, https://doi.org/10.1016/S0341-8162(78)80002-2.
    Goldberg, E.D., 1963, Geochronology with 210 Pb, in Miller, J.A., convener, Radioactive dating: International Atomic Energy Agency Symposium on Radioactive Dating, Athens, Greece, November 19-23, 1962, [Proceedings], p. 121-131. Person who carried out this activity:
    Meagan J Eagle
    Northeast Region: WOODS HOLE COASTAL and MARINE SCIENCE CENTER
    Research Physical Scientist
    384 Woods Hole Road
    Woods Hole, MA
    US

    508-548-8700 x2280 (voice)
    meagle@usgs.gov
    Date: 2021 (process 4 of 4)
    For data in the entity, Data_PR_Cores.csv (and Data_PR_Cores.xlsx), raw data were entered into Excel spreadsheets where calculations for radionuclide decays per minute per gram (dpm/g), dry bulk density, percent carbon, percent nitrogen, and carbon and nitrogen isotope content were completed. Calculations are described in the process steps for each analysis or in each attribute definition. These calculated values were compiled into a CSV file using Microsoft Excel. The CSV file was processed in MATLAB to round calculated values to appropriate place values and truncate extra digits; it was then exported as a comma separated text file (*.csv). Using Microsoft Excel, this exported file was edited to allow for preferential use of special characters and formats, and re-saved as a CSV UTF-8 file, Data_PR_Cores.csv, included in this data release.
    The entity, Data_PR_AgeModel.csv, is an output from analysis in R in which we used a bootstrap approach to generate means and 95% confidence bounds for each parameter within cores and specific time periods. The bootstrap analysis generated 1,000 sets of randomly selected data from the reported values for the given core/time period (Efron and Tibshirani 1993). The mean of those 1,000 values was used as the overall mean estimate for the parameter, and the 2.5th and 97.5th percentiles of those 1,000 values were the upper and lower confidence bounds. We report age means and 95% confidence intervals in the age-depth profiles for each core and use these estimates to calculate accretion rates. This file is saved as csv UTF-8.
    Note that all calculations were performed prior to rounding and truncating values reported in this data release. Microsoft Excel (*.xlsx) versions of each entity are provided for users to verify proper text formatting that may not be preserved when opening the .csv files in certain editors.
    Efron, B., and Tibshirani, R.J., 1993, An Introduction to the Bootstrap. Boca Raton, FL: Chapman and Hall/CRC. Person who carried out this activity:
    Meagan J Eagle
    Northeast Region: WOODS HOLE COASTAL and MARINE SCIENCE CENTER
    Research Physical Scientist
    384 Woods Hole Road
    Woods Hole, MA
    US

    508-548-8700 x2280 (voice)
    meagle@usgs.gov
  3. What similar or related data should the user be aware of?
    Wigand, Cathleen, Eagle, Meagan, Branoff, Benjamin, Balogh, Stephen, Miller, Kenneth, M., Martin, Rose M., Hanson, Alana, Oczkowski, Autumn J., Huertas, Evelyn, Loffredo, Joseph, and Watson, Elizabeth B., 2021, Recent carbon storage and burial exceed historic rates in the San Juan Bay Estuary peri-urban mangrove forests (Puerto Rico, USA): Frontiers in Forests and Global Change doi: 10.3389/ffgc.2021.676691, Creative Commons, Mountain View, CA.

    Online Links:

    Other_Citation_Details: The journal article this data release supports.

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    One core collected from Martin Peña West (MPW) was damaged during air transport to the US mainland and was not radiometrically dated. Additionally, only one of the two replicates from the San José (SJ) lagoon was processed for dry bulk density (DBD) due to human error, so DBD values from one SJ core were used in calculations of C storage and sequestration for both replicates from that site.
    Radionuclide detection limits are specific to an individual sample and are a function of: 1) the detector efficiency at the energy level of the peak being measured; 2) the branching ratio (expected fraction of decay events at the energy level), 3) the background activity within the sample. Detector efficiency was determined from EPA standard pitchblende ore in the same geometry as the samples. Activities of 7Be, 137Cs, and excess 210Pb (i.e. unsupported) were decay-corrected to time of collection. Suppression of low energy peaks by self-absorption was corrected for according to Cutshall and others, 1983. Peak detection, with respect to background activity, is calculated for each radionuclide in the APTEC peak integration spectroscopy software during sample analysis. Generally, measured radionuclide activity greater than or equal to 0.08 (210Pb), 0.05 (226Ra), 2.17 (7Be), and 0.08 (137Cs) dpm/g were accepted as above detection limit for this dataset.
    The C and N isotope compositions were determined using an Elementar Vario Micro elemental analyzer connected to a continuous flow Isoprime 100 isotope ratio mass spectrometer (IRMS) (Elementar Americas, Mt. Laurel, NJ). Replicate analyses of isotopic standard reference materials USGS 40 (δ13C = -26.39 ‰; δ15N = -4.52 ‰) and USGS 41 (δ13C = 37.63 ‰; δ15N = 47.57 ‰) were used to normalize isotopic values of working standards to the air (δ15N) and Vienna Pee Dee Belemnite (δ13C) scales (Paul and others, 2007). Working standards were analyzed after every 24 samples to monitor instrument performance and check data normalization. The precision of the laboratory standards was better than ± 0.3‰ for δ13C and δ15N. The %C and %N were calculated by comparing the peak area of the unknown sample to a standard curve of peak area versus the C or N content of a known standard.
    Paul, D., Skrzypek, G. and Fórizs, I. (2007). Normalization of measured stable isotopic compositions to isotope reference scales – A review. Rapid Communications in Mass Spectrometry 21 (18): 3006–3014.
    Cutshall, N.H., Larsen, I.L., and Olsen, C.R., 1983, Direct analysis of 210 Pb in sediment samples—Self-absorption corrections: Nuclear Instruments and Methods in Physics Research, v. 206, issues 1–2, p. 309–312, https://doi.org/10.1016/0167-5087(83)91273-5.
  2. How accurate are the geographic locations?
    Latitude and longitude were measured in the field at time of sediment core collection using the Soft Stack Dev application, Map Coordinates (http://softstackdev.com/), on a GPS-enabled smart phone. The GPS coordinates are accurate to within 5 meters. Duplicate sediment cores were collected from within 1 meter of each other, the same latitude and longitude are reported for all cores collected from each site.
  3. How accurate are the heights or depths?
    Samples were collected every centimeter in the core using a meter stick affixed to the core tube as a reference. Sample depth is defined as the interval within the core. No formal positional accuracy tests were conducted.
  4. Where are the gaps in the data? What is missing?
    One core collected from Martin Peña West (MPW) was damaged during air transport to the US mainland and was not radiometrically dated. Additionally, only one of the two replicates from the San José (SJ) lagoon was processed for dry bulk density (DBD) due to human error, so DBD values from one SJ core were used in calculations of C storage and sequestration for both replicates from that site. Otherwise, cores collected were treated in the same manner. All sample measurements are reported.
  5. How consistent are the relationships among the observations, including topology?
    Dataset was queried for maximum and minimum values to be sure sample analyses were within expected ranges for the environmental conditions. Data were plotted to look for any obvious outliers that may have been indicative of analytical error. Samples with questionable results were re-analyzed. Detection limits are defined in the attribute accuracy section of the metadata. Any analysis value below detection is given the numerical value of 0. Any attribute that was not measured for a specific sample is listed as an empty or blank cell (in some instances, empty spaces were used as place holders for blank cells). Each sample was treated in the same manner for each analysis. Note that 7Be was not detectable in this sample set.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints none
Use_Constraints none
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey
    Attn: ScienceBase
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO
    United States

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? The dataset contains two CSV files containing the data (Data_PR_Cores.csv; Data_PR_AgeModel.csv) as well as two Microsoft Excel files (Data_PR_Cores.xlsx; Data_PR_AgeModel.xlsx), the browse graphic, and the FGDC CSDGM metadata in XML format.
  3. What legal disclaimers am I supposed to read?
    Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  4. How can I download or order the data?
    • Availability in digital form:
      Data format: The data release includes 2 comma separated files, 2 Excel files, a browse graphic, and the FGDC CSDGM metadata. Mirosoft Excel versions of each entitiy are provided for users to verify proper text formatting that may not be preserved when opening the CSV UTF-8 files in certain editors. in format CSV (version Microsoft Excel Office 365) Size: 1
      Network links: https://www.sciencebase.gov/catalog/file/get/60902e3fd34e93746a710491
      https://doi.org/10.5066/P97CAF30
      Data format: The data release includes 2 comma separated files, 2 Excel files, a browse graphic, and the FGDC CSDGM metadata. Mirosoft Excel versions of each entitiy are provided for users to verify proper text formatting that may not be preserved when opening the CSV UTF-8 files in certain editors. in format XLSX (version Microsoft Excel Office 365) Size: 1
      Network links: https://www.sciencebase.gov/catalog/file/get/60902e3fd34e93746a710491
      https://doi.org/10.5066/P97CAF30
    • Cost to order the data: None

  5. What hardware or software do I need in order to use the data set?
    The data release includes 2 comma-delimited text files. The user must have software capable of opening the text file and reading the data formats.

Who wrote the metadata?

Dates:
Last modified: 19-Mar-2024
Metadata author:
Jennifer A. O'Keefe Suttles
Northeast Region: WOODS HOLE COASTAL and MARINE SCIENCE CENTER
Chemist
384 Woods Hole Road
Woods Hole, MA
United States

508-548-8700 x2385 (voice)
whsc_data_contact@usgs.gov
Contact_Instructions:
The metadata contact email address is a generic address in the event the person is no longer with USGS. (updated on 20240319)
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/SB_data_release/DR_P97CAF30/Meta_PR_cores.faq.html>
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