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     data   graph     files  public Denitrification and DNRA data from Little Lagoon, Alabama collected from 2012-2013    ?     I   M   background (external link) RSS Subscribe BCO-DMO bcodmo_dataset_723966

The Dataset's Variables and Attributes

Row Type Variable Name Attribute Name Data Type Value
attribute NC_GLOBAL access_formats String .htmlTable,.csv,.json,.mat,.nc,.tsv
attribute NC_GLOBAL acquisition_description String Little Lagoon is a shallow coastal lagoon that is tidally connected to the
Gulf of Mexico but has no riverine inputs. The water in the lagoon is
replenished solely from precipitation and groundwater inputs primarily on the
East end (Su et al. 2012). Because of the rapid development in Baldwin County,
a large amount of NO3- enters the Little Lagoon system through SGD (Murgulet &
Tick 2008). In this region, there can be rapid changes in the depth to
groundwater (Fig. 4.1 inset) and episodic SGD inputs to the lagoon (Su et
al.2013). Within the lagoon, three sites were selected (East, Mouth, and West)
to represent the gradient that exists across the lagoon from the input of
groundwater. Sites were sampled on a near-monthly basis from February 2012 to
February 2013.

Approximately 1 L of outflow water was collected from the inflow water and
each core forDNRA analysis. Appropriate sample volume was determined after NH4
+ nutrient analysis and expected atom % enrichment. \u03b415N-NH4 + was
measured in samples, constructed blanks, and standards that bracketed the NH4
+ concentration of the samples following a modified ammonium diffusion
procedure (Holmes et al. 1998) that collects NH4 + dissolved in water by
converting NH4 + to NH3 under basic conditions and then traps the NH3 on an
acidified glass fiber filter. Non diffused standards were prepared according
to Stark and Hart (1996) to account for blank corrections. After 15N analysis
on a Europa Scientific SL-2020 system (Stable Isotope Lab, Utah State
University), DNRA was calculated from the production rate of 15NH4 + (p15NH4
+) during the incubation according to Christensen et. al (2000): (7) where is
the production of 15N-NH4 + and D14 and D15 are the denitrification rates of
14N-NO3 - and 15N-NO3 -, respectively. This assumes that DNRA takes place in
the same sediment layers as denitrification and that the 15N labeling of NO3 -
being reduced to NH4 + equals the 15N labeling of NO3 - being reduced to N2
(Christensen et al. 2000).

Denitrification and anammox from slurry assays

Volumetric rates of denitrification, anammox, and the relative contribution of
anammox to gross N2 production were determined from sediment slurry
incubations. Slurry rates for depth-integrated sediments (0-50 mm) were
prepared in Exetainers (Thamdrup & Dalsgaard 2002) with artificial seawater
(ASW) (70.2g NaCl, 3.0g KCl, 49.4 g MgSO4*7H2O, 5.8g CaCl2*2H2O L-1)
constructed at a salinity of 52 and diluted with deionized water to match the
salinity of each site. After dilution, homogenized sediment from 0 to 50 mm
was added to the ASW and the incubation bottle was sparged with N2 and amended
with 100 \u03bcmol L-1 Na15NO3 - (99 atom %). Sediment slurry was dispensed to
12 ml Exetainers, yielding approximately 1 ml of sediment and 11 ml ASW with
no headspace. For each site, 12 vials total were incubated with three vials
stopped at time points 0 to 36 h. Incubations were stopped by adding 250
\u03bcL of ZnCl2 and resealing the vials without headspace. Denitrification
and anammox rates in slurries were calculated according to equations 5 and 6
described below.\u00a0

Excess 29N2 and 30N2 concentrations for intact core and slurry incubations
were calculated from dissolved 29N2:28N2 and 30N2:28N2 measured using a MIMS.
Rates of excess 29N2 (p29) and 30N2 (p30) production were calculated from the
flux calculation described above. Rates of ambient 14N2 production (p14) in
core incubations with 15NO3 - tracer addition were determined as (Nielsen
1992, Risgaard-Petersen et al. 2003):\u00a0

(1) p14 = 2 x r14 \u00b1 [p29 + p30 \u00b1 (1 - r16)]

The 14N:15N ratio of NO3 - undergoing reduction to N2 (r14) was determined as

(2) r14 = [R29 x (1 - ra) - ra] x (2 - ra) ^-1

where R29 was the ratio of p29 to p30 determined for the cores and ra was the
relative contribution of anammox to gross N2 production determined in vial
slurry incubations. Gross denitrification and anammox rates within intact
sediment cores with 15NO3 - tracer addition were calculated as follows:\u00a0

(3) denitrification = p14 \u00b1 (1 - ra)

(4) anammox = p14 \u00b1 ra

Denitrification stimulated by the added 15N-NO3 - (D15) was calculated from
the classical IPT (Nielsen 1992) and these amended rates are a measure of the
denitrification capacity under field conditions when NO3 - is not

Rates of denitrification and anammox in vial slurry incubations with 15NO3 -
amendments were calculated from the equations of Thamdrup and Dalsgaard
(2002): (5) (6) where FN was the fraction of 15N in NO3 -. For months when
anammox slurry incubations were not performed (August and November 2012), p14
is calculated as D14 from the IPT (Nielsen 1992). Potential denitrification
and anammox rates were converted to an areal basis using the wet weight of the
sediment in the slurry. All rates and fluxes pertaining to N species in this
study were normalized to one atom N.

Additional methodology can be found in:

Bernard, Rebecca & Mortazavi, Behzad & A. Kleinhuizen, Alice. (2015).
Dissimilatory nitrate reduction to ammonium (DNRA) seasonally dominates
NO3\u2212 reduction pathways in an anthropogenically impacted sub-tropical
coastal lagoon. Biogeochemistry. 125.
attribute NC_GLOBAL awards_0_award_nid String 497637
attribute NC_GLOBAL awards_0_award_number String OCE-0962008
attribute NC_GLOBAL awards_0_data_url String http://nsf.gov/awardsearch/showAward?AWD_ID=0962008 (external link)
attribute NC_GLOBAL awards_0_funder_name String NSF Division of Ocean Sciences
attribute NC_GLOBAL awards_0_funding_acronym String NSF OCE
attribute NC_GLOBAL awards_0_funding_source_nid String 355
attribute NC_GLOBAL awards_0_program_manager String David L. Garrison
attribute NC_GLOBAL awards_0_program_manager_nid String 50534
attribute NC_GLOBAL cdm_data_type String Other
attribute NC_GLOBAL comment String Denitrification and DNRA
B. Mortazavi and W. Burnett, PIs
Version 16 January 2018
attribute NC_GLOBAL Conventions String COARDS, CF-1.6, ACDD-1.3
attribute NC_GLOBAL creator_email String info at bco-dmo.org
attribute NC_GLOBAL creator_name String BCO-DMO
attribute NC_GLOBAL creator_type String institution
attribute NC_GLOBAL creator_url String https://www.bco-dmo.org/ (external link)
attribute NC_GLOBAL data_source String extract_data_as_tsv version 2.3 19 Dec 2019
attribute NC_GLOBAL date_created String 2018-01-17T20:11:39Z
attribute NC_GLOBAL date_modified String 2019-03-15T18:07:13Z
attribute NC_GLOBAL defaultDataQuery String &time<now
attribute NC_GLOBAL doi String 10.1575/1912/bco-dmo.723966.1
attribute NC_GLOBAL infoUrl String https://www.bco-dmo.org/dataset/723966 (external link)
attribute NC_GLOBAL institution String BCO-DMO
attribute NC_GLOBAL instruments_0_acronym String IR Mass Spec
attribute NC_GLOBAL instruments_0_dataset_instrument_description String Used for 15N analysis
attribute NC_GLOBAL instruments_0_dataset_instrument_nid String 724410
attribute NC_GLOBAL instruments_0_description String The Isotope-ratio Mass Spectrometer is a particular type of mass spectrometer used to measure the relative abundance of isotopes in a given sample (e.g. VG Prism II Isotope Ratio Mass-Spectrometer).
attribute NC_GLOBAL instruments_0_instrument_external_identifier String https://vocab.nerc.ac.uk/collection/L05/current/LAB16/ (external link)
attribute NC_GLOBAL instruments_0_instrument_name String Isotope-ratio Mass Spectrometer
attribute NC_GLOBAL instruments_0_instrument_nid String 469
attribute NC_GLOBAL instruments_0_supplied_name String Europa Scientific SL-2020 system
attribute NC_GLOBAL instruments_1_dataset_instrument_description String Used to filter sediment
attribute NC_GLOBAL instruments_1_dataset_instrument_nid String 724409
attribute NC_GLOBAL instruments_1_description String A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action. Pumps can be classified into three major groups according to the method they use to move the fluid: direct lift, displacement, and gravity pumps
attribute NC_GLOBAL instruments_1_instrument_name String Pump
attribute NC_GLOBAL instruments_1_instrument_nid String 726
attribute NC_GLOBAL instruments_1_supplied_name String Multichannel proportioning pump
attribute NC_GLOBAL instruments_2_acronym String MIMS
attribute NC_GLOBAL instruments_2_dataset_instrument_description String Used to measure dissolved gas
attribute NC_GLOBAL instruments_2_dataset_instrument_nid String 724407
attribute NC_GLOBAL instruments_2_description String Membrane-introduction mass spectrometry (MIMS) is a method of introducing analytes into the mass spectrometer's vacuum chamber via a semipermeable membrane.
attribute NC_GLOBAL instruments_2_instrument_name String Membrane Inlet Mass Spectrometer
attribute NC_GLOBAL instruments_2_instrument_nid String 661606
attribute NC_GLOBAL instruments_2_supplied_name String MIMS
attribute NC_GLOBAL instruments_3_acronym String CFA
attribute NC_GLOBAL instruments_3_dataset_instrument_description String Used to measure continuous flow rate
attribute NC_GLOBAL instruments_3_dataset_instrument_nid String 724408
attribute NC_GLOBAL instruments_3_description String A sample is injected into a flowing carrier solution passing rapidly through small-bore tubing.
attribute NC_GLOBAL instruments_3_instrument_name String Continuous Flow Analyzer
attribute NC_GLOBAL instruments_3_instrument_nid String 661968
attribute NC_GLOBAL instruments_3_supplied_name String Continuous Flow Analyzer
attribute NC_GLOBAL keywords String bco, bco-dmo, biological, chemical, data, dataset, date, description, dmo, east, East_SE, erddap, management, mouth, Mouth_SE, oceanography, office, preliminary, value, Value_Description, west, West_SE, year
attribute NC_GLOBAL license String https://www.bco-dmo.org/dataset/723966/license (external link)
attribute NC_GLOBAL metadata_source String https://www.bco-dmo.org/api/dataset/723966 (external link)
attribute NC_GLOBAL param_mapping String {'723966': {}}
attribute NC_GLOBAL parameter_source String https://www.bco-dmo.org/mapserver/dataset/723966/parameters (external link)
attribute NC_GLOBAL people_0_affiliation String National Science Foundation
attribute NC_GLOBAL people_0_affiliation_acronym String NSF-DEB
attribute NC_GLOBAL people_0_person_name String Dr Behzad Mortazavi
attribute NC_GLOBAL people_0_person_nid String 491316
attribute NC_GLOBAL people_0_role String Principal Investigator
attribute NC_GLOBAL people_0_role_type String originator
attribute NC_GLOBAL people_1_affiliation String Florida State University
attribute NC_GLOBAL people_1_affiliation_acronym String FSU - EOAS
attribute NC_GLOBAL people_1_person_name String Dr William C. Burnett
attribute NC_GLOBAL people_1_person_nid String 491315
attribute NC_GLOBAL people_1_role String Co-Principal Investigator
attribute NC_GLOBAL people_1_role_type String originator
attribute NC_GLOBAL people_2_affiliation String National Science Foundation
attribute NC_GLOBAL people_2_affiliation_acronym String NSF-DEB
attribute NC_GLOBAL people_2_person_name String Dr Behzad Mortazavi
attribute NC_GLOBAL people_2_person_nid String 491316
attribute NC_GLOBAL people_2_role String Contact
attribute NC_GLOBAL people_2_role_type String related
attribute NC_GLOBAL people_3_affiliation String Woods Hole Oceanographic Institution
attribute NC_GLOBAL people_3_affiliation_acronym String WHOI BCO-DMO
attribute NC_GLOBAL people_3_person_name String Hannah Ake
attribute NC_GLOBAL people_3_person_nid String 650173
attribute NC_GLOBAL people_3_role String BCO-DMO Data Manager
attribute NC_GLOBAL people_3_role_type String related
attribute NC_GLOBAL project String LittleLagoonGroundwater
attribute NC_GLOBAL projects_0_acronym String LittleLagoonGroundwater
attribute NC_GLOBAL projects_0_description String This project investigated the link between submarine groundwater discharge (SGD) and microalgal dynamics in Little Lagoon, Alabama.  In contrast to most near-shore environments, it is fully accessible; has no riverine inputs; and is large enough to display ecological diversity (c. 14x 0.75 km) yet small enough to be comprehensively sampled on appropriate temporal and spatial scales. The PIs have previously demonstrated that the lagoon is a hot-spot for toxic blooms of the diatom Pseudo-nitzchia spp. that are correlated with discharge from the surficial aquifer. This project assessed variability in SGD, the dependence of benthic nutrient fluxes on microphytobenthos (MPB) abundance and productivity, and the response of the phytoplankton to nutrient enrichment and dilution. The work integrated multiple temporal and spatial scales and demonstrated both the relative importance of SGD vs. benthic recycling as a source of nutrients, and the role of SGD in structuring the microalgal community. (paraphrased from Award abstract)
attribute NC_GLOBAL projects_0_end_date String 2014-08
attribute NC_GLOBAL projects_0_geolocation String southern Alabama, east of Mobile
attribute NC_GLOBAL projects_0_name String Groundwater Discharge, Benthic Coupling and Microalgal Community Structure in a Shallow Coastal Lagoon
attribute NC_GLOBAL projects_0_project_nid String 491318
attribute NC_GLOBAL projects_0_start_date String 2010-03
attribute NC_GLOBAL publisher_name String Biological and Chemical Oceanographic Data Management Office (BCO-DMO)
attribute NC_GLOBAL publisher_type String institution
attribute NC_GLOBAL sourceUrl String (local files)
attribute NC_GLOBAL standard_name_vocabulary String CF Standard Name Table v55
attribute NC_GLOBAL summary String Denitrification and DNRA data from Little Lagoon, Alabama collected from 2012-2013
attribute NC_GLOBAL title String Denitrification and DNRA data from Little Lagoon, Alabama collected from 2012-2013
attribute NC_GLOBAL version String 1
attribute NC_GLOBAL xml_source String osprey2erddap.update_xml() v1.3
variable Year   byte  
attribute Year _FillValue byte 127
attribute Year actual_range byte 1, 2
attribute Year bcodmo_name String unknown
attribute Year description String Year ID that samples were taken
attribute Year long_name String Year
attribute Year units String unitless
variable Value_Description   String  
attribute Value_Description bcodmo_name String unknown
attribute Value_Description description String Description of the measurment taken; description includes relevant units for each sample taken; Descriptions include: DIN:DIP = ratio of dissolved inorganic nitrogen to dissolved inorganic phosphate; Denitrification = Denitrification; p14 ambient denitrification = ambient denitrification rates; DNRA = dissimilatory nitrate reduction to ammonium; D15 denitrification = denitrification from added heavy labeled isotope.
attribute Value_Description long_name String Value Description
attribute Value_Description units String unitless
variable Date   String  
attribute Date bcodmo_name String date
attribute Date description String Month and day that samples were taken; MMM-DD
attribute Date long_name String Date
attribute Date nerc_identifier String https://vocab.nerc.ac.uk/collection/P01/current/ADATAA01/ (external link)
attribute Date units String unitless
variable East   float  
attribute East _FillValue float NaN
attribute East actual_range float -55.13, 5072.2
attribute East bcodmo_name String N
attribute East description String Denitrification and DNRA values collected at the East site; location of site is 30.253347, -87.724729
attribute East long_name String East
attribute East units String umol N m-2 hr-1; umol N m-2 d-1; mmol NH4+ m-2 d-1
variable East_SE   float  
attribute East_SE _FillValue float NaN
attribute East_SE actual_range float 0.0, 1260.2
attribute East_SE bcodmo_name String N
attribute East_SE description String Standard error of denitrification and DNRA values collected at the East site
attribute East_SE long_name String East SE
attribute East_SE units String umol N m-2 hr-1; umol N m-2 d-1; mmol NH4+ m-2 d-1
variable Mouth   float  
attribute Mouth _FillValue float NaN
attribute Mouth actual_range float -52.28, 2549.4
attribute Mouth bcodmo_name String N
attribute Mouth description String Denitrification and DNRA values collected at the Mouth site; location of site is 30.243683, -87.738407
attribute Mouth long_name String Mouth
attribute Mouth units String umol N m-2 hr-1; umol N m-2 d-1; mmol NH4+ m-2 d-1
variable Mouth_SE   float  
attribute Mouth_SE _FillValue float NaN
attribute Mouth_SE actual_range float 0.0, 458.2
attribute Mouth_SE bcodmo_name String N
attribute Mouth_SE description String Standard error of denitrification and DNRA values collected at the Mouth site
attribute Mouth_SE long_name String Mouth SE
attribute Mouth_SE units String umol N m-2 hr-1; umol N m-2 d-1; mmol NH4+ m-2 d-1
variable West   float  
attribute West _FillValue float NaN
attribute West actual_range float -77.78, 5678.0
attribute West bcodmo_name String N
attribute West description String Denitrification and DNRA values collected at the West site; location of site is 30.247181, -87.767856
attribute West long_name String West
attribute West units String umol N m-2 hr-1; umol N m-2 d-1; mmol NH4+ m-2 d-1
variable West_SE   float  
attribute West_SE _FillValue float NaN
attribute West_SE actual_range float 0.0, 1181.1
attribute West_SE bcodmo_name String N
attribute West_SE description String Standard error of denitrification and DNRA values collected at the West site
attribute West_SE long_name String West SE
attribute West_SE units String umol N m-2 hr-1; umol N m-2 d-1; mmol NH4+ m-2 d-1

The information in the table above is also available in other file formats (.csv, .htmlTable, .itx, .json, .jsonlCSV1, .jsonlCSV, .jsonlKVP, .mat, .nc, .nccsv, .tsv, .xhtml) via a RESTful web service.

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