gov.noaa.nodc:0223379 eng utf8 dataset NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact HTTPS NOAA Contact Information Information for contacts at NCEI. information custodian 2025-05-16T15:50:33Z ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) Denitrification Capacity of a Natural and a Restored Marsh in the Northern Gulf of Mexico from 2014-02-27 to 2015-02-26 (NCEI Accession 0223379) 2021-01-13 publication 2020-12-18 creation NOAA National Centers for Environmental Information gov.noaa.nodc:0223379 NCEI Archive Management System 0223379 NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact HTTPS NCEI Contact Information Information for contacts at NCEI. information publisher Lei Hu Dauphin Island Sea Lab (DISL) lhu@disl.org https://www.disl.edu/ HTTPS Dauphin Island Sea Lab (DISL) website Institution web page information resourceProvider Dauphin Island Sea Lab (DISL) https://www.disl.edu/ HTTPS Dauphin Island Sea Lab (DISL) website Institution web page information resourceProvider Behzad Mortazavi University of Alabama (UA) bmortazavi@ua.edu principalInvestigator Mortazavi, Behzad University of Alabama author Kleinhuizen, Alice University of Alabama author tableDigital This dataset includes denitrification rates across a typical northern Gulf of Mexico salt marsh landscape that included a natural marsh, a tidal creek, and a 21-year-old restored salt marsh. Denitrification capacity, measured with the isotope pairing technique on a membrane inlet mass spectrometer, was comparable across the sites despite significant differences in above and below ground characteristics. Total extractable ammonium concentrations and sediment carbon content were higher at the natural marsh compared to the restored marsh. Hydrogen sulfide concentrations were highest at the creek compared to the vegetated sites and lowest at the restored marsh. This suggests that marsh restoration projects reestablish nitrogen removal capacity at rates similar to those in natural systems and can help to significantly reduce nitrogen loads to the coastal ocean. This dataset on denitrification rates in restored and a nearby natural marsh are used to demonstrate that restored marshes can achieve nitrogen removal capacity that is similar to that natural marshes. This is despite some differences with the lower carbon content and total extractable ammonium and porewater phosphate, and nitrate and hydrogen sulfide concentrations compared to the natural marsh. While not all ecosystem attributes recover at the same rate following restoration, functions like nitrogen removal appear to recover and help with removing nitrogen that would otherwise be exported to nearby coastal waters. Funding Agency: National Science Foundation completed historicalArchive NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact HTTPS NCEI Contact Information Information for contacts at NCEI. information pointOfContact asNeeded https://www.ncei.noaa.gov/access/metadata/landing-page/bin/gfx?id=gov.noaa.nodc:0223379 Preview graphic PNG 0223379 NCEI ACCESSION NUMBER 2020-11-16 publication AMMONIUM (NH4) NITRATE nitrate + nitrite content (concentration) NITRITE phosphate SALINITY WATER TEMPERATURE theme NODC DATA TYPES THESAURUS CHN Analyzer GPS multi-parameter water quality sensor nutrient autoanalyzer sediment sampler - corer instrument NODC INSTRUMENT TYPES THESAURUS in situ theme NODC OBSERVATION TYPES THESAURUS Dauphin Island Sea Lab dataCentre NODC SUBMITTING INSTITUTION NAMES THESAURUS Coastal Waters of Gulf of Mexico place NODC SEA AREA NAMES THESAURUS oceanography theme WMO_CategoryCode 2012-09-15 publication EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > AMMONIA EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > NITRATE EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > NITRITE EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > PHOSPHATE EARTH SCIENCE > OCEANS > OCEAN TEMPERATURE > WATER TEMPERATURE EARTH SCIENCE > OCEANS > SALINITY/DENSITY > SALINITY theme Global Change Master Directory (GCMD) Science Keywords 2026 revision 24 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian C:N Carbon content of the sediment as percentage Chl-a extracted from sediments (mg m-2) D14 (denitrification rates from ambient nitrate) (uM N m-2 hr-1) D15 (denitrification rates from added 15 nitrate isotope) (uM N m-2 hr-1) DNF (Denitrification) Capacity (uM N m-2 hr-1) Dn14 (coupled nitriciation-denitrification) (uM N m-2 hr-1) Dn14 percent of D14 Dried organic biomass above ground (kg m-2) Dried organic biomass belowground in experiment cores to a depth of 20 cm (kg m-2) Dw14 (direct denitrification rates of in situ water column nitrate) (uM N m-2 hr-1) Elevation NH4 extracted from sediments in nmole g-1 dry sediment NH4 flux rates (uM N m-2 hr-1) NO3 flux rates (uM N m-2 hr-1) PO4 flux rates (uM N m-2 hr-1) Porewater NH4 at 10 cm depth (micromolar) Porewater NO2 at 10 cm depth (micromolar) Porewater NO3 at 10 cm depth (micromolar) Porewater NOx at 10 cm depth (micromolar) Porewater PO4 at 10 cm depth (micromolar) Porewater Sulfide at 10 cm depth (micromolar) Sample replicates Sampling site type Seawater NH4 (micromolar) Seawater NO2 (micromolar) Seawater NO3 (micromolar) Seawater NOx (micromolar) Seawater PO4 (micromolar) theme Provider Keywords AUTOANALYZER > AUTOANALYZER CHN ANALYZERS > Carbon, Hydrogen, Nitrogen Analyzers GPS RECEIVERS > GPS RECEIVERS SEDIMENT CORERS > SEDIMENT CORERS instrument Global Change Master Directory (GCMD) Instrument Keywords 2026 revision 24 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian 0.25 m2 quadrat Carlo Erba element analyzer Core tubes Membrane Inlet Mass Spectrometer Porewater sipper Skalar SAN + Autoanalyzer Trimble NetRS GPS Triplicate cores (ID 2.6 cm) YSI 556 Multiparameter meter cut off syringe corer (I.D. 1.3cm) instrument Provider Instrument Types OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > GULF OF AMERICA OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > GULF OF MEXICO place Global Change Master Directory (GCMD) Location Keywords 2026 revision 24 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian PMTKP3 Send2NCEI Submission Package ID accessLevel: public otherRestrictions Cite as: Mortazavi, Behzad; Kleinhuizen, Alice (2021). Denitrification Capacity of a Natural and a Restored Marsh in the Northern Gulf of Mexico from 2014-02-27 to 2015-02-26 (NCEI Accession 0223379). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0223379. Accessed [date]. Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives. otherRestrictions Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose. Kleinhuizen, A. A., & Mortazavi, B. (2018). Denitrification Capacity of a Natural and a Restored Marsh in the Northern Gulf of Mexico. Environmental Management, 62(3), 584–594. https://doi.org/10.1007/s00267-018-1057-y 2018-05-07 publication International DOI Foundation (IDF) https://doi.org/10.1007/s00267-018-1057-y https://doi.org/10.1007/s00267-018-1057-y HTTPS https://doi.org/10.1007/s00267-018-1057-y related journal article information Kleinhuizen, Alice A. author Mortazavi, Behzad Syracuse University author Springer Science and Business Media LLC publisher documentDigital Environmental Management 62(3) ISSN 0364-152X, ISSN 1432-1009, pp. 584-594 crossReference sciencePaper eng; USA utf8 environment oceans -88.0828 -88.0778 30.2508 30.2522 2014-02-27 2015-02-26 Additional sampling and analyzing information from submitter: The marsh platform elevations were measured at the beginning of the study with a Trimble NetRS GPS receiver and are reported relative to the NAV 83 (conus) datum, region 16N. In June 2014 triplicate cores to a depth of 10 cm were collected. Dried sediments were ground with a mortar and pestle and percent carbon and nitrogen contents of the sediments were measured on a Carlo Erba elemental analyzer. In June 2014 triplicate cores to a depth of 10 cm were collected. Dried sediments were ground with a mortar and pestle and percent carbon and nitrogen contents of the sediments were measured on a Carlo Erba elemental analyzer. Five cores (9.5 cm, 24 cm Height) were collected bimonthly during low tide at each site to a depth of 20 cm. Cores tubes were pushed into the marsh soil within patches of J. roemerianus at the natural and restored marsh sites within 5 cm of the vegetation base taking care not to include aboveground vegetation in the core. Belowground biomass was removed from each core by rinsing the cores and drying the material retained on a 2 mm sieve to dry weight at 60 degrees Celsius. At the natural marsh, aboveground vegetation was harvested bimonthly (n = 3) by placing 0.25 m2 quadrants over a patch of J. roemerianus and collecting the vegetation. Stems were dried at 60°C to a constant weight and aboveground mass per area was determined. Because the restored marsh is part of a public education and outreach center, vegetation could not be harvested frequently. Therefore, stems of J. roemerianus at the restored site were harvested at one time and individual stem heights were measured and dry weights recorded. A height versus mass vegetation regression was fit to this log transformed data (y = 1.33 × −2.48, R2 = 0.94) and used to estimate above- ground biomass from stem densities and heights in 0.25 m2 quadrats during bimonthly surveys (n = 3). Sediment Chl-α content was determined for samples collected in triplicate with a cut off syringe (I.D. 1.3 cm) to a depth of 1 cm. Sediments were freeze dried and extracted for 24 h in 90% acetone. Concentrations were determined fluorometrically and normalized per gram dry sediment. Porewaters from a depth of 10 cm were collected approximately biweekly during high tide from each sipper and along with triplicate surface water samples were glass fiber filtered (GF/F, 0.7 μm pore size) and nalyzed for dissolved inorganic nutrients. Nitrate, nitrite. Ammonium, and phosphate were measured on a Skalar SAN+ Autoanalyzer. Triplicate cores (2.6 cm ID) from the top 10 cm of sediments were collected biweekly at each site for analysis of total sediment extractable NH4 . One gram of homogenized sediments was weighed into 50 mL centrifuge tubes and extracted for 10 h with 10 mL of 1 M NaCl (Smith and Caffrey 2009) on a shaker table at 60 rpm. Samples were then centrifuged at 4500 rpm for 10 min and the supernatant was GF/F filtered and frozen prior to analyses as previously described. Triplicate cores (2.6 cm ID) from the top 10 cm of sediments were collected biweekly at each site for analysis of total sediment extractable NH4 . One gram of homogenized sediments was weighed into 50 mL centrifuge tubes and extracted for 10 h with 10 mL of 1 M NaCl (Smith and Caffrey 2009) on a shaker table at 60 rpm. Samples were then centrifuged at 4500 rpm for 10 min and the supernatant was GF/F filtered and frozen prior to analyses as previously described. The five bimonthly cores were capped underwater avoiding air bubbles and inflow and outflow tubing was connected to each core. Filtered site water (GF/F) spiked with sodium 15N-nitrate to a final concentration of 50 μM flowed through each core for 24 hr with a peristaltic pump at a rate of 2.5 mL per minute. Each core contained a magnetic stir bar suspended from the caps that stirred the overlying water. Water samples for NH4 Flux, NO3 Flux, and PO4 Flux were collected after 24 hours. Water samples were filtered through GF/F and frozen. NH4 and PO4 concentrations were measured on a Skalar SAN+ Autoanalyzer. NO3 concentrations were determined with a combination of VCl3 reduction as described in Schnetger B, Lehners C (2014). At the same time as nutrient flux samples, triplicate samples from the inflow and outflow line of each core for analysis of nitrogen gas isotopes were collected in 12 mL Exetainers by overflowing the volume of the vial twice and then preserving the samples with 250 μL of 50% w/v ZnCl2. Samples were capped and stored underwater until analysis for nitrogen gas isotopes on a membrane inlet mass spectrometer. NOAA National Centers for Environmental Information +1-301-713-3277 ncei.info@noaa.gov pointOfContact In most cases, electronic downloads of the data are free. However, fees may apply for custom orders, data certifications, copies of analog materials, and data distribution on physical media. Contact NCEI for other distribution options and instructions. Originator data format 0.332 https://www.ncei.noaa.gov/archive/accession/0223379 HTTPS Web browser NCEI Dataset Landing Page Navigate directly to the URL for a descriptive web page with download links. information https://www.ncei.noaa.gov/archive/accession/oas/223379 HTTPS Web browser Descriptive Information Navigate directly to the URL for a descriptive web page with download links. information https://www.ncei.noaa.gov/archive/accession/download/223379 HTTPS Web browser HTTPS Navigate directly to the URL for data access and direct download. download ftp://ftp-oceans.ncei.noaa.gov/nodc/archive/arc0166/0223379/ FTP Any FTP client FTP These data are available through the File Transfer Protocol (FTP). FTP is no longer supported by most internet browsers. You may copy and paste the FTP link to the data into an FTP client (e.g., FileZilla or WinSCP). download dataset NCEI Accession 0223379 v1.1 was published. 2021-01-13T22:35:33Z NCEI Accession 0223379 v1.1 publication https://www.ncei.noaa.gov/archive/accession/0223379/1.1 HTTPS NCEI Accession 0223379 v1.1 published 2021-01-13T22:35:33Z download dataset Parameter or Variable: Abiotic_date (measured); Units: NA; Observation Category: in situ; Sampling Instrument: NA; Sampling and Analyzing Method: Calendar date the sample was collected In mm/dd/yyyy format Parameter or Variable: Abiotic_Site (measured); Units: NA; Observation Category: in situ; Sampling Instrument: CHN Analyzer; Sampling and Analyzing Method: Sampling site the sample was collected Parameter or Variable: temperature (measured); Units: Celsius; Observation Category: in situ; Sampling Instrument: YSI 556 Multiparameter meter; Sampling and Analyzing Method: Water temperature in degrees Celsius Parameter or Variable: SALINITY (measured); Units: psu; Observation Category: in situ; Sampling Instrument: YSI 556 Multiparameter meter; Sampling and Analyzing Method: Water salinity in PSU Parameter or Variable: Site (measured); Units: NA; Observation Category: in situ; Sampling Instrument: NA; Sampling and Analyzing Method: Sampling site the sample was collected Parameter or Variable: Replicate (measured); Units: NA; Observation Category: in situ; Sampling Instrument: NA; Sampling and Analyzing Method: Sample replicate Parameter or Variable: Elevation (measured); Units: meters; Observation Category: in situ; Sampling Instrument: NA; Sampling and Analyzing Method: Elevation of the site measured in meters. Parameter or Variable: Carbon Content (measured); Units: Carbon content of the sediments as a %; Observation Category: in situ; Sampling Instrument: Trimble NetRS GPS; Sampling and Analyzing Method: The marsh platform elevations were measured at the beginning of the study with a Trimble NetRS GPS receiver and are reported relative to the NAV 83 (conus) datum, region 16N. In June 2014 triplicate cores to a depth of 10 cm were collected. Dried sediments were ground with a mortar and pestle and percent carbon and nitrogen contents of the sediments were measured on a Carlo Erba elemental analyzer. Parameter or Variable: C:N (measured); Units: Molar Ratios of Carbon to Nitrogen; Observation Category: in situ; Sampling Instrument: Carlo Erba elemental analyzer; Sampling and Analyzing Method: In June 2014 triplicate cores to a depth of 10 cm were collected. Dried sediments were ground with a mortar and pestle and percent carbon and nitrogen contents of the sediments were measured on a Carlo Erba elemental analyzer. Parameter or Variable: Below_biomass_Date (measured); Units: NA; Observation Category: in situ; Sampling Instrument: NA; Sampling and Analyzing Method: Calendar date the sample was collected In M/D/YYYY format Parameter or Variable: Below_biomass_site (measured); Units: NA; Observation Category: in situ; Sampling Instrument: NA; Sampling and Analyzing Method: Sampling site the sample was collected Parameter or Variable: Below_biomass_Core (measured); Units: NA; Observation Category: in situ; Sampling Instrument: NA; Sampling and Analyzing Method: Core replicate Parameter or Variable: Below Biomass (measured); Units: Dried organic biomass belowground in experiment cores to a depth of 20 cm in kg m-2; Observation Category: in situ; Sampling Instrument: Cores tubes; Sampling and Analyzing Method: Five cores (9.5 cm, 24 cm Height) were collected bimonthly during low tide at each site to a depth of 20 cm. Cores tubes were pushed into the marsh soil within patches of J. roemerianus at the natural and restored marsh sites within 5 cm of the vegetation base taking care not to include aboveground vegetation in the core. Belowground biomass was removed from each core by rinsing the cores and drying the material retained on a 2 mm sieve to dry weight at 60 degrees Celsius. Parameter or Variable: Above_Biomass_Date (measured); Units: NA; Observation Category: in situ; Sampling Instrument: NA; Sampling and Analyzing Method: Calendar date the above biomass sample was collected In M/D/Y format Parameter or Variable: Above_Biomass_Site (measured); Units: NA; Observation Category: in situ; Sampling Instrument: NA; Sampling and Analyzing Method: Sampling site the above biomass sample was collected Parameter or Variable: Above_Biomass_Replicate (measured); Units: NA; Observation Category: in situ; Sampling Instrument: NA; Sampling and Analyzing Method: Above biomass Sample replicate Parameter or Variable: Above Biomass (calculated); Units: Dried organic biomass above ground in kg m-2; Observation Category: in situ; Sampling Instrument: 0.25 m2 quadrat; Sampling and Analyzing Method: At the natural marsh, aboveground vegetation was harvested bimonthly (n = 3) by placing 0.25 m2 quadrants over a patch of J. roemerianus and collecting the vegetation. Stems were dried at 60°C to a constant weight and aboveground mass per area was determined. Because the restored marsh is part of a public education and outreach center, vegetation could not be harvested frequently. Therefore, stems of J. roemerianus at the restored site were harvested at one time and individual stem heights were measured and dry weights recorded. A height versus mass vegetation regression was fit to this log transformed data (y = 1.33 × −2.48, R2 = 0.94) and used to estimate above- ground biomass from stem densities and heights in 0.25 m2 quadrats during bimonthly surveys (n = 3). Parameter or Variable: chlorophyll_Date (measured); Units: NA; Observation Category: in situ; Sampling Instrument: NA; Sampling and Analyzing Method: Calendar date the chlorophyll sample was collected In M/D/Y format Parameter or Variable: chlorophyll_Site (measured); Units: NA; Observation Category: in situ; Sampling Instrument: NA; Sampling and Analyzing Method: Sampling site the chlorophyll sample was collected Parameter or Variable: chlorophyll_Replicate (measured); Units: NA; Observation Category: in situ; Sampling Instrument: NA; Sampling and Analyzing Method: chlorophyll sample replicate Parameter or Variable: Chl-a Extracted (measured); Units: Chlorophyll concentrations extracted from sediments in mg m-2; Observation Category: in situ; Sampling Instrument: Cut off syringe corer (I.D. 1.3 cm); Sampling and Analyzing Method: Sediment Chl-α content was determined for samples collected in triplicate with a cut off syringe (I.D. 1.3 cm) to a depth of 1 cm. Sediments were freeze dried and extracted for 24 h in 90% acetone. Concentrations were determined fluorometrically and normalized per gram dry sediment. Parameter or Variable: nutrients_Date (measured); Units: NA; Observation Category: in situ; Sampling Instrument: NA; Sampling and Analyzing Method: Calendar date the nutrients sample was collected In M/D/Y format Parameter or Variable: nutrients_Site (measured); Units: NA; Observation Category: in situ; Sampling Instrument: NA; Sampling and Analyzing Method: Sampling site the nutrients sample was collected Parameter or Variable: nutrients_Replicate (measured); Units: NA; Observation Category: in situ; Sampling Instrument: NA; Sampling and Analyzing Method: Nutrients sample replicate Parameter or Variable: SW NOx (measured); Units: Concentration of Nitrate plus Nitrite in the surface water in µM; Observation Category: in situ; Sampling Instrument: a Skalar SAN+ Autoanalyzer; Sampling and Analyzing Method: Porewaters from a depth of 10 cm were collected approximately biweekly during high tide from each sipper and along with triplicate surface water samples were glass fiber filtered (GF/F, 0.7 μm pore size) and nalyzed for dissolved inorganic nutrients. Nitrate, nitrite. Ammonium, and phosphate were measured on a Skalar SAN+ Autoanalyzer. Triplicate cores (2.6 cm ID) from the top 10 cm of sediments were collected biweekly at each site for analysis of total sediment extractable NH4 . One gram of homogenized sediments was weighed into 50 mL centrifuge tubes and extracted for 10 h with 10 mL of 1 M NaCl (Smith and Caffrey 2009) on a shaker table at 60 rpm. Samples were then centrifuged at 4500 rpm for 10 min and the supernatant was GF/F filtered and frozen prior to analyses as previously described. Parameter or Variable: SW NO2 (measured); Units: Concentration of Nitrite in the surface water in µM; Observation Category: in situ; Sampling Instrument: a Skalar SAN+ Autoanalyzer; Sampling and Analyzing Method: Porewaters from a depth of 10 cm were collected approximately biweekly during high tide from each sipper and along with triplicate surface water samples were glass fiber filtered (GF/F, 0.7 μm pore size) and analyzed for dissolved inorganic nutrients. Nitrate, nitrite. Ammonium, and phosphate were measured on a Skalar SAN+ Autoanalyzer. Triplicate cores (2.6 cm ID) from the top 10 cm of sediments were collected biweekly at each site for analysis of total sediment extractable NH4 . One gram of homogenized sediments was weighed into 50 mL centrifuge tubes and extracted for 10 h with 10 mL of 1 M NaCl (Smith and Caffrey 2009) on a shaker table at 60 rpm. Samples were then centrifuged at 4500 rpm for 10 min and the supernatant was GF/F filtered and frozen prior to analyses as previously described. Parameter or Variable: SW NO3 (measured); Units: Concentration of Nitrate in the surface water in µM; Observation Category: in situ; Sampling Instrument: a Skalar SAN+ Autoanalyzer; Sampling and Analyzing Method: Porewaters from a depth of 10 cm were collected approximately biweekly during high tide from each sipper and along with triplicate surface water samples were glass fiber filtered (GF/F, 0.7 μm pore size) and analyzed for dissolved inorganic nutrients. Nitrate, nitrite. Ammonium, and phosphate were measured on a Skalar SAN+ Autoanalyzer. Triplicate cores (2.6 cm ID) from the top 10 cm of sediments were collected biweekly at each site for analysis of total sediment extractable NH4 . One gram of homogenized sediments was weighed into 50 mL centrifuge tubes and extracted for 10 h with 10 mL of 1 M NaCl (Smith and Caffrey 2009) on a shaker table at 60 rpm. Samples were then centrifuged at 4500 rpm for 10 min and the supernatant was GF/F filtered and frozen prior to analyses as previously described. Parameter or Variable: SW PO4 (measured); Units: Concentration of Phosphate in the surface water in µM; Observation Category: in situ; Sampling Instrument: a Skalar SAN+ Autoanalyzer; Sampling and Analyzing Method: Porewaters from a depth of 10 cm were collected approximately biweekly during high tide from each sipper and along with triplicate surface water samples were glass fiber filtered (GF/F, 0.7 μm pore size) and analyzed for dissolved inorganic nutrients. Nitrate, nitrite. Ammonium, and phosphate were measured on a Skalar SAN+ Autoanalyzer. Triplicate cores (2.6 cm ID) from the top 10 cm of sediments were collected biweekly at each site for analysis of total sediment extractable NH4 . One gram of homogenized sediments was weighed into 50 mL centrifuge tubes and extracted for 10 h with 10 mL of 1 M NaCl (Smith and Caffrey 2009) on a shaker table at 60 rpm. Samples were then centrifuged at 4500 rpm for 10 min and the supernatant was GF/F filtered and frozen prior to analyses as previously described. Parameter or Variable: SW NH4 (measured); Units: Concentration of Ammonium in the surface water in µM; Observation Category: in situ; Sampling Instrument: a Skalar SAN+ Autoanalyzer; Sampling and Analyzing Method: Porewaters from a depth of 10 cm were collected approximately biweekly during high tide from each sipper and along with triplicate surface water samples were glass fiber filtered (GF/F, 0.7 μm pore size) and analyzed for dissolved inorganic nutrients. Nitrate, nitrite. Ammonium, and phosphate were measured on a Skalar SAN+ Autoanalyzer. Triplicate cores (2.6 cm ID) from the top 10 cm of sediments were collected biweekly at each site for analysis of total sediment extractable NH4 . One gram of homogenized sediments was weighed into 50 mL centrifuge tubes and extracted for 10 h with 10 mL of 1 M NaCl (Smith and Caffrey 2009) on a shaker table at 60 rpm. Samples were then centrifuged at 4500 rpm for 10 min and the supernatant was GF/F filtered and frozen prior to analyses as previously described. Parameter or Variable: PW NOx (measured); Units: Concentration of Nitrate plus Nitrite in the pore water at 10 cm depth in µM; Observation Category: in situ; Sampling Instrument: Porewater sipper; Sampling and Analyzing Method: Porewaters from a depth of 10 cm were collected approximately biweekly during high tide from each sipper and along with triplicate surface water samples were glass fiber filtered (GF/F, 0.7 μm pore size) and analyzed for dissolved inorganic nutrients. Nitrate, nitrite. Ammonium, and phosphate were measured on a Skalar SAN+ Autoanalyzer. Triplicate cores (2.6 cm ID) from the top 10 cm of sediments were collected biweekly at each site for analysis of total sediment extractable NH4 . One gram of homogenized sediments was weighed into 50 mL centrifuge tubes and extracted for 10 h with 10 mL of 1 M NaCl (Smith and Caffrey 2009) on a shaker table at 60 rpm. Samples were then centrifuged at 4500 rpm for 10 min and the supernatant was GF/F filtered and frozen prior to analyses as previously described. Parameter or Variable: PW NO2 (measured); Units: Concentration of Nitrite in the pore water at 10 cm depth in µM; Observation Category: in situ; Sampling Instrument: Porewater sipper; Sampling and Analyzing Method: Porewaters from a depth of 10 cm were collected approximately biweekly during high tide from each sipper and along with triplicate surface water samples were glass fiber filtered (GF/F, 0.7 μm pore size) and analyzed for dissolved inorganic nutrients. Nitrate, nitrite. Ammonium, and phosphate were measured on a Skalar SAN+ Autoanalyzer. Triplicate cores (2.6 cm ID) from the top 10 cm of sediments were collected biweekly at each site for analysis of total sediment extractable NH4 . One gram of homogenized sediments was weighed into 50 mL centrifuge tubes and extracted for 10 h with 10 mL of 1 M NaCl (Smith and Caffrey 2009) on a shaker table at 60 rpm. Samples were then centrifuged at 4500 rpm for 10 min and the supernatant was GF/F filtered and frozen prior to analyses as previously described. Parameter or Variable: PW NO3 (measured); Units: Concentration of Nitrate in the pore water at 10 cm depth in µM; Observation Category: in situ; Sampling Instrument: Porewater sipper; Sampling and Analyzing Method: Porewaters from a depth of 10 cm were collected approximately biweekly during high tide from each sipper and along with triplicate surface water samples were glass fiber filtered (GF/F, 0.7 μm pore size) and analyzed for dissolved inorganic nutrients. Nitrate, nitrite. Ammonium, and phosphate were measured on a Skalar SAN+ Autoanalyzer. Triplicate cores (2.6 cm ID) from the top 10 cm of sediments were collected biweekly at each site for analysis of total sediment extractable NH4 . One gram of homogenized sediments was weighed into 50 mL centrifuge tubes and extracted for 10 h with 10 mL of 1 M NaCl (Smith and Caffrey 2009) on a shaker table at 60 rpm. Samples were then centrifuged at 4500 rpm for 10 min and the supernatant was GF/F filtered and frozen prior to analyses as previously described. Parameter or Variable: PW NH4 (measured); Units: Concentration of Ammonium in the pore water at 10 cm depth in µM; Observation Category: in situ; Sampling Instrument: Porewater sipper; Sampling and Analyzing Method: Porewaters from a depth of 10 cm were collected approximately biweekly during high tide from each sipper and along with triplicate surface water samples were glass fiber filtered (GF/F, 0.7 μm pore size) and analyzed for dissolved inorganic nutrients. Nitrate, nitrite. Ammonium, and phosphate were measured on a Skalar SAN+ Autoanalyzer. Triplicate cores (2.6 cm ID) from the top 10 cm of sediments were collected biweekly at each site for analysis of total sediment extractable NH4 . One gram of homogenized sediments was weighed into 50 mL centrifuge tubes and extracted for 10 h with 10 mL of 1 M NaCl (Smith and Caffrey 2009) on a shaker table at 60 rpm. Samples were then centrifuged at 4500 rpm for 10 min and the supernatant was GF/F filtered and frozen prior to analyses as previously described. Parameter or Variable: PW PO4 (measured); Units: Concentration of Phosphate in the pore water at 10 cm depth in µM; Observation Category: in situ; Sampling Instrument: Porewater sipper; Sampling and Analyzing Method: Porewaters from a depth of 10 cm were collected approximately biweekly during high tide from each sipper and along with triplicate surface water samples were glass fiber filtered (GF/F, 0.7 μm pore size) and analyzed for dissolved inorganic nutrients. Nitrate, nitrite. Ammonium, and phosphate were measured on a Skalar SAN+ Autoanalyzer. Triplicate cores (2.6 cm ID) from the top 10 cm of sediments were collected biweekly at each site for analysis of total sediment extractable NH4 . One gram of homogenized sediments was weighed into 50 mL centrifuge tubes and extracted for 10 h with 10 mL of 1 M NaCl (Smith and Caffrey 2009) on a shaker table at 60 rpm. Samples were then centrifuged at 4500 rpm for 10 min and the supernatant was GF/F filtered and frozen prior to analyses as previously described. Parameter or Variable: Sulfide (measured); Units: Concentration of Hydrogen Sulfide in the pore water at 10 cm depth in µM; Observation Category: in situ; Sampling Instrument: Skalar SAN+ Autoanalyzer; Sampling and Analyzing Method: Porewaters from a depth of 10 cm were collected approximately biweekly during high tide from each sipper and along with triplicate surface water samples were glass fiber filtered (GF/F, 0.7 μm pore size) and analyzed for dissolved inorganic nutrients. Nitrate, nitrite. Ammonium, and phosphate were measured on a Skalar SAN+ Autoanalyzer. Triplicate cores (2.6 cm ID) from the top 10 cm of sediments were collected biweekly at each site for analysis of total sediment extractable NH4 . One gram of homogenized sediments was weighed into 50 mL centrifuge tubes and extracted for 10 h with 10 mL of 1 M NaCl (Smith and Caffrey 2009) on a shaker table at 60 rpm. Samples were then centrifuged at 4500 rpm for 10 min and the supernatant was GF/F filtered and frozen prior to analyses as previously described. Parameter or Variable: NH4 Extracted (measured); Units: Ammonium concentration extracted from sediments in nmole g-1 dry sediment; Observation Category: in situ; Sampling Instrument: Triplicate cores (2.6 cm ID); Sampling and Analyzing Method: Triplicate cores (2.6 cm ID) from the top 10 cm of sediments were collected biweekly at each site for analysis of total sediment extractable NH4 . One gram of homogenized sediments was weighed into 50 mL centrifuge tubes and extracted for 10 h with 10 mL of 1 M NaCl (Smith and Caffrey 2009) on a shaker table at 60 rpm. Samples were then centrifuged at 4500 rpm for 10 min and the supernatant was GF/F filtered and frozen prior to analyses as previously described. Parameter or Variable: fluxes_Date (measured); Units: N/A; Observation Category: in situ; Sampling Instrument: Calendar date the sample was collected In M/D/Y format Parameter or Variable: fluxes_Site (measured); Units: N/A; Observation Category: in situ; Sampling Instrument: Sampling site the sample was collected Parameter or Variable: fluxes_Core (measured); Units: N/A; Observation Category: in situ; Sampling Instrument: Core replicate Parameter or Variable: NH4 Flux (measured); Units: Ammonium flux rates measured in µmol N m-2 hr-1; Observation Category: in situ; Sampling Instrument: Skalar SAN+ Autoanalyzer; Sampling and Analyzing Method: Five cores (9.5 cm, ID, 24 cm height) were collected bimonthly during low tide at each site to a depth of 20 cm. Cores tubes were pushed into the marsh soil within patches of J. roemerianus at the natural and restored marsh sites within 5 cm of the vegetation base taking care not to include aboveground vegetation in the core. Cores were then capped underwater avoiding air bubbles and inflow and outflow tubing was connected to each core. Filtered site water (GF/F) spiked with sodium 15N-nitrate to a final concentration of 50 μM flowed through each core for 24 hr with a peristaltic pump at a rate of 2.5 mL per minute. Each core contained a magnetic stir bar suspended from the caps that stirred the overlying water. Water samples for NH4 Flux, NO3 Flux, and PO4 Flux were collected after 24 hours. Water samples were filtered through GF/F and frozen. NH4 and PO4 concentrations were measured on a Skalar SAN+ Autoanalyzer. NO3 concentrations were determined with a combination of VCl3 reduction as described in Schnetger B, Lehners C (2014). At the same time as nutrient flux samples, triplicate samples from the inflow and outflow line of each core for analysis of nitrogen gas isotopes were collected in 12 mL Exetainers by overflowing the volume of the vial twice and then preserving the samples with 250 μL of 50% w/v ZnCl2. Samples were capped and stored underwater until analysis for nitrogen gas isotopes on a membrane inlet mass spectrometer. Parameter or Variable: NO3 Flux (measured); Units: Nitrate flux rates measured in µmol N m-2 hr-1; Observation Category: in situ; Sampling Instrument: Skalar SAN+ Autoanalyzer; Sampling and Analyzing Method: Five cores (9.5 cm, ID, 24 cm height) were collected bimonthly during low tide at each site to a depth of 20 cm. Cores tubes were pushed into the marsh soil within patches of J. roemerianus at the natural and restored marsh sites within 5 cm of the vegetation base taking care not to include aboveground vegetation in the core. Cores were then capped underwater avoiding air bubbles and inflow and outflow tubing was connected to each core. Filtered site water (GF/F) spiked with sodium 15N-nitrate to a final concentration of 50 μM flowed through each core for 24 hr with a peristaltic pump at a rate of 2.5 mL per minute. Each core contained a magnetic stir bar suspended from the caps that stirred the overlying water. Water samples for NH4 Flux, NO3 Flux, and PO4 Flux were collected after 24 hours. Water samples were filtered through GF/F and frozen. NH4 and PO4 concentrations were measured on a Skalar SAN+ Autoanalyzer. NO3 concentrations were determined with a combination of VCl3 reduction as described in Schnetger B, Lehners C (2014). At the same time as nutrient flux samples, triplicate samples from the inflow and outflow line of each core for analysis of nitrogen gas isotopes were collected in 12 mL Exetainers by overflowing the volume of the vial twice and then preserving the samples with 250 μL of 50% w/v ZnCl2. Samples were capped and stored underwater until analysis for nitrogen gas isotopes on a membrane inlet mass spectrometer. Parameter or Variable: PO4 Flux (measured); Units: Phosphate flux rates measured in µmol P m-2 hr-1; Observation Category: in situ; Sampling Instrument: Skalar SAN+ Autoanalyzer; Sampling and Analyzing Method: Five cores (9.5 cm, ID, 24 cm height) were collected bimonthly during low tide at each site to a depth of 20 cm. Cores tubes were pushed into the marsh soil within patches of J. roemerianus at the natural and restored marsh sites within 5 cm of the vegetation base taking care not to include aboveground vegetation in the core. Cores were then capped underwater avoiding air bubbles and inflow and outflow tubing was connected to each core. Filtered site water (GF/F) spiked with sodium 15N-nitrate to a final concentration of 50 μM flowed through each core for 24 hr with a peristaltic pump at a rate of 2.5 mL per minute. Each core contained a magnetic stir bar suspended from the caps that stirred the overlying water. Water samples for NH4 Flux, NO3 Flux, and PO4 Flux were collected after 24 hours. Water samples were filtered through GF/F and frozen. NH4 and PO4 concentrations were measured on a Skalar SAN+ Autoanalyzer. NO3 concentrations were determined with a combination of VCl3 reduction as described in Schnetger B, Lehners C (2014). At the same time as nutrient flux samples, triplicate samples from the inflow and outflow line of each core for analysis of nitrogen gas isotopes were collected in 12 mL Exetainers by overflowing the volume of the vial twice and then preserving the samples with 250 μL of 50% w/v ZnCl2. Samples were capped and stored underwater until analysis for nitrogen gas isotopes on a membrane inlet mass spectrometer. Parameter or Variable: DNF Capacity (measured); Units: Denitrification rates measured in µmol N m-2 hr-1; Observation Category: in situ; Sampling Instrument: Membrane Inlet Mass Spectrometer; Sampling and Analyzing Method: Five cores (9.5 cm, ID, 24 cm height) were collected bimonthly during low tide at each site to a depth of 20 cm. Cores tubes were pushed into the marsh soil within patches of J. roemerianus at the natural and restored marsh sites within 5 cm of the vegetation base taking care not to include aboveground vegetation in the core. Cores were then capped underwater avoiding air bubbles and inflow and outflow tubing was connected to each core. Filtered site water (GF/F) spiked with sodium 15N-nitrate to a final concentration of 50 μM flowed through each core for 24 hr with a peristaltic pump at a rate of 2.5 mL per minute. Each core contained a magnetic stir bar suspended from the caps that stirred the overlying water. Water samples for NH4 Flux, NO3 Flux, and PO4 Flux were collected after 24 hours. Water samples were filtered through GF/F and frozen. NH4 and PO4 concentrations were measured on a Skalar SAN+ Autoanalyzer. NO3 concentrations were determined with a combination of VCl3 reduction as described in Schnetger B, Lehners C (2014). At the same time as nutrient flux samples, triplicate samples from the inflow and outflow line of each core for analysis of nitrogen gas isotopes were collected in 12 mL Exetainers by overflowing the volume of the vial twice and then preserving the samples with 250 μL of 50% w/v ZnCl2. Samples were capped and stored underwater until analysis for nitrogen gas isotopes on a membrane inlet mass spectrometer. Parameter or Variable: D14 (measured); Units: Denitrification rates from ambient nitrate measured in µmol N m-2 hr-1; Observation Category: in situ; Sampling Instrument: Membrane Inlet Mass Spectrometer; Sampling and Analyzing Method: Five cores (9.5 cm, ID, 24 cm height) were collected bimonthly during low tide at each site to a depth of 20 cm. Cores tubes were pushed into the marsh soil within patches of J. roemerianus at the natural and restored marsh sites within 5 cm of the vegetation base taking care not to include aboveground vegetation in the core. Cores were then capped underwater avoiding air bubbles and inflow and outflow tubing was connected to each core. Filtered site water (GF/F) spiked with sodium 15N-nitrate to a final concentration of 50 μM flowed through each core for 24 hr with a peristaltic pump at a rate of 2.5 mL per minute. Each core contained a magnetic stir bar suspended from the caps that stirred the overlying water. Water samples for NH4 Flux, NO3 Flux, and PO4 Flux were collected after 24 hours. Water samples were filtered through GF/F and frozen. NH4 and PO4 concentrations were measured on a Skalar SAN+ Autoanalyzer. NO3 concentrations were determined with a combination of VCl3 reduction as described in Schnetger B, Lehners C (2014). At the same time as nutrient flux samples, triplicate samples from the inflow and outflow line of each core for analysis of nitrogen gas isotopes were collected in 12 mL Exetainers by overflowing the volume of the vial twice and then preserving the samples with 250 μL of 50% w/v ZnCl2. Samples were capped and stored underwater until analysis for nitrogen gas isotopes on a membrane inlet mass spectrometer. Parameter or Variable: D15 (measured); Units: Denitrification rates from added 15 nitrate isotope measured in µmol N m-2 hr-1; Observation Category: in situ; Sampling Instrument: Membrane Inlet Mass Spectrometer; Sampling and Analyzing Method: Five cores (9.5 cm, ID, 24 cm height) were collected bimonthly during low tide at each site to a depth of 20 cm. Cores tubes were pushed into the marsh soil within patches of J. roemerianus at the natural and restored marsh sites within 5 cm of the vegetation base taking care not to include aboveground vegetation in the core. Cores were then capped underwater avoiding air bubbles and inflow and outflow tubing was connected to each core. Filtered site water (GF/F) spiked with sodium 15N-nitrate to a final concentration of 50 μM flowed through each core for 24 hr with a peristaltic pump at a rate of 2.5 mL per minute. Each core contained a magnetic stir bar suspended from the caps that stirred the overlying water. Water samples for NH4 Flux, NO3 Flux, and PO4 Flux were collected after 24 hours. Water samples were filtered through GF/F and frozen. NH4 and PO4 concentrations were measured on a Skalar SAN+ Autoanalyzer. NO3 concentrations were determined with a combination of VCl3 reduction as described in Schnetger B, Lehners C (2014). At the same time as nutrient flux samples, triplicate samples from the inflow and outflow line of each core for analysis of nitrogen gas isotopes were collected in 12 mL Exetainers by overflowing the volume of the vial twice and then preserving the samples with 250 μL of 50% w/v ZnCl2. Samples were capped and stored underwater until analysis for nitrogen gas isotopes on a membrane inlet mass spectrometer. Parameter or Variable: Dw14 (measured); Units: Direct denitrification rates of in situ water column nitrate measured in µmol N m-2 hr-1; Observation Category: in situ; Sampling Instrument: Membrane Inlet Mass Spectrometer; Sampling and Analyzing Method: Five cores (9.5 cm, ID, 24 cm height) were collected bimonthly during low tide at each site to a depth of 20 cm. Cores tubes were pushed into the marsh soil within patches of J. roemerianus at the natural and restored marsh sites within 5 cm of the vegetation base taking care not to include aboveground vegetation in the core. Cores were then capped underwater avoiding air bubbles and inflow and outflow tubing was connected to each core. Filtered site water (GF/F) spiked with sodium 15N-nitrate to a final concentration of 50 μM flowed through each core for 24 hr with a peristaltic pump at a rate of 2.5 mL per minute. Each core contained a magnetic stir bar suspended from the caps that stirred the overlying water. Water samples for NH4 Flux, NO3 Flux, and PO4 Flux were collected after 24 hours. Water samples were filtered through GF/F and frozen. NH4 and PO4 concentrations were measured on a Skalar SAN+ Autoanalyzer. NO3 concentrations were determined with a combination of VCl3 reduction as described in Schnetger B, Lehners C (2014). At the same time as nutrient flux samples, triplicate samples from the inflow and outflow line of each core for analysis of nitrogen gas isotopes were collected in 12 mL Exetainers by overflowing the volume of the vial twice and then preserving the samples with 250 μL of 50% w/v ZnCl2. Samples were capped and stored underwater until analysis for nitrogen gas isotopes on a membrane inlet mass spectrometer. Parameter or Variable: Dn14 (measured); Units: Coupled nitrification-denitrification measured in µmol N m-2 hr-1; Observation Category: in situ; Sampling Instrument: Membrane Inlet Mass Spectrometer; Sampling and Analyzing Method: Five cores (9.5 cm, ID, 24 cm height) were collected bimonthly during low tide at each site to a depth of 20 cm. Cores tubes were pushed into the marsh soil within patches of J. roemerianus at the natural and restored marsh sites within 5 cm of the vegetation base taking care not to include aboveground vegetation in the core. Cores were then capped underwater avoiding air bubbles and inflow and outflow tubing was connected to each core. Filtered site water (GF/F) spiked with sodium 15N-nitrate to a final concentration of 50 μM flowed through each core for 24 hr with a peristaltic pump at a rate of 2.5 mL per minute. Each core contained a magnetic stir bar suspended from the caps that stirred the overlying water. Water samples for NH4 Flux, NO3 Flux, and PO4 Flux were collected after 24 hours. Water samples were filtered through GF/F and frozen. NH4 and PO4 concentrations were measured on a Skalar SAN+ Autoanalyzer. NO3 concentrations were determined with a combination of VCl3 reduction as described in Schnetger B, Lehners C (2014). At the same time as nutrient flux samples, triplicate samples from the inflow and outflow line of each core for analysis of nitrogen gas isotopes were collected in 12 mL Exetainers by overflowing the volume of the vial twice and then preserving the samples with 250 μL of 50% w/v ZnCl2. Samples were capped and stored underwater until analysis for nitrogen gas isotopes on a membrane inlet mass spectrometer. Parameter or Variable: Dn14 % of D14 (measured); Units: see in Data Quality Method; Observation Category: in situ; Sampling Instrument: Membrane Inlet Mass Spectrometer; Sampling and Analyzing Method: Five cores (9.5 cm, ID, 24 cm height) were collected bimonthly during low tide at each site to a depth of 20 cm. Cores tubes were pushed into the marsh soil within patches of J. roemerianus at the natural and restored marsh sites within 5 cm of the vegetation base taking care not to include aboveground vegetation in the core. Cores were then capped underwater avoiding air bubbles and inflow and outflow tubing was connected to each core. Filtered site water (GF/F) spiked with sodium 15N-nitrate to a final concentration of 50 μM flowed through each core for 24 hr with a peristaltic pump at a rate of 2.5 mL per minute. Each core contained a magnetic stir bar suspended from the caps that stirred the overlying water. Water samples for NH4 Flux, NO3 Flux, and PO4 Flux were collected after 24 hours. Water samples were filtered through GF/F and frozen. NH4 and PO4 concentrations were measured on a Skalar SAN+ Autoanalyzer. NO3 concentrations were determined with a combination of VCl3 reduction as described in Schnetger B, Lehners C (2014). At the same time as nutrient flux samples, triplicate samples from the inflow and outflow line of each core for analysis of nitrogen gas isotopes were collected in 12 mL Exetainers by overflowing the volume of the vial twice and then preserving the samples with 250 μL of 50% w/v ZnCl2. Samples were capped and stored underwater until analysis for nitrogen gas isotopes on a membrane inlet mass spectrometer.; Data Quality Method: Percent of in situ denitrification (D14) from coupled nitrification-denitrification (Dn14) measured in % (This info is too long to enter in the Units field.) asNeeded Metadata are developed, maintained and distributed by NCEI. Updates are performed as needed to maintain currentness. NOAA National Centers for Environmental Information custodian CHN Analyzer CHN Analyzer Carbon, Hydrogen, and Nitrogen Analyzer Instrument used for measuring carbon, hydrogen, and nitrogen in organic and other types of materials. GPS GPS Global Positioning System receiver satellite-based instrument used for geo-location, positioning and navigation multi-parameter water quality sensor multi-parameter water quality sensor used to measure temperature, salinity, dissolved oxygen, and other parameters Instrument used to measure temperature, salinity, dissolved oxygen, and other parameters, often used to measure water quality parameters. Can be a hand-held instrument or a sonde for unattended monitoring. Often used in coastal water monitoring stations. YSI is the preeminent brand (as of 2024). nutrient autoanalyzer nutrient autoanalyzer Laboratory Instrument Nutrient Autoanalyzer is a generic term describing an automated flow-thru system used to conduct analyses of several different nutrients (nitrate, ammonium, orthophosphate, and silicate) simultaneously from a seawater sample. For example: SEAL AutoAnalyzer 3 HR Continuous Segmented Flow Analyzer sediment sampler - corer sediment sampler - corer sediment coring device gravity or other coring device used to collect surfacial and near-surficial sediment samples