Dataset: STING macronutrient concentrations

Name: Dissolved Macronutrient Concentrations from Depth Profiles and Incubation Experiments from STING I Cruise AE2305 on R/V Atlantic Explorer in the Gulf of Mexico from February to March 2023
Published: 2024-06-04
Keywords: STING, nutrient, West Florida shelf, oceans

View Data: Data not available yet

Cite This Dataset

Spatial Extent: N:28.5 E:-82.5 S:26.3 W:-86.6

Eastern Gulf of Mexico and West Florida Shelf

Temporal Extent: 2023-02-20 - 2023-03-05

Project:

Collaborative Research: Linking iron and nitrogen sources in an oligotrophic coastal margin: Nitrogen fixation and the role of boundary fluxes (Gulf of Mexico DON and Fe)

Principal Investigator:

Kristen Nicolle Buck (University of South Florida, USF)

Co-Principal Investigator:

Rene Maurice Boiteau (Oregon State University, OSU)

Phoebe Dreux Chappell (Old Dominion University, ODU)

Timothy M. Conway (University of South Florida, USF)

Angela N. Knapp (Florida State University, FSU)

Chris Smith (United States Geological Survey, USGS)

Joseph Tamborski (Old Dominion University, ODU)

Scientist:

Salvatore Caprara (University of South Florida, USF)

Student:

Caitlyn Elizabeth Parente (University of South Florida, USF)

BCO-DMO Data Manager:

Sawyer Newman (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2024-06-04

Restricted:

Yes

Release Date:

2025-03-01

Validated:

Current State:

Preliminary and in progress

Dissolved Macronutrient Concentrations from Depth Profiles and Incubation Experiments from STING I Cruise AE2305 on R/V Atlantic Explorer in the Gulf of Mexico from February to March 2023

Abstract:

Concentrations of inorganic dissolved macronutrients, including phosphate, nitrate plus nitrite (N+N), silicic acid, and nitrite, from phytoplankton shipboard incubation experiments and depth profiles collected on STING I cruise AE2305 on R/V Atlantic Explorer in the Gulf of Mexico from February to March 2023. This project investigates how groundwater discharge delivers important nutrients to the coastal ecosystems of the West Florida Shelf. Preliminary studies indicate that groundwater may supply both dissolved organic nitrogen (DON) and iron in this region. In coastal ecosystems like the West Florida Shelf that have very low nitrate and ammonium concentrations, DON is the main form of nitrogen available to organisms. Nitrogen cycling is strongly affected by iron availability because iron is essential for both photosynthesis and for nitrogen fixation. This study will investigate the sources and composition of DON and iron, and their influence on the coastal ecosystem. The team will sample offshore groundwater wells, river and estuarine waters, and conduct two expeditions across the West Florida Shelf in winter and summer.

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Methods & Sampling

Water column samples were collected in February and March 2023 aboard the R/V Atlantic Explorer using a trace metal clean rosette (SeaBird) outfitted with 12-L Niskin-X samplers (Ocean Test Equipment), a trace metal clean pump, or a custom surface pump “towfish” system (Mellett and Buck, 2020). Seawater samples for macronutrient analysis were filtered through 0.2 µm Pall Acropak Super membrane filter capsules, collected in acid-cleaned and triple-rinsed 15-mL Falcon tubes, and stored in ziplock bags in the fridge until analyzed shipboard following recommended practices (Becker et al., 2020), typically within 24 hours of collection.

Samples were analyzed shipboard for phosphate, nitrate+nitrite, silicate, and nitrite on a QuAAtro39 AutoAnalyzer (SEAL Analytical) according to standard colorimetric methods (Strickland and Parsons, 1972). All reagents were prepared in dedicated labware with high purity Milli-Q (>18 MΩ cm) water. Working standards were prepared fresh daily in an artificial seawater (ASW; 35 g/L sodium chloride, 0.5 g/L sodium bicarbonate) matrix using calibrated volumetric pipettes.

Nine-point standard curves were analyzed at the beginning of each run with multiple reagent blanks. Quality control checks were analyzed every twelfth sample with ASW blanks and standards. The highest standard from the calibration curve was analyzed approximately every twenty samples to check for drift during the runs. Subsamples of reference material for nutrients in seawater (Konso) were measured in each run (see Table 1 below).

Detection limits for each parameter were determined from three times the standard deviation of replicate lowest standards. Limits of detection were 0.035 µM for phosphate, 0.048 µM for nitrate+nitrite, 0.051 µM for silicate, and 0.012 µM for nitrite. Values below detection are reported as 0 µM with accompanying QC Flag 6.

Sample analyses for macronutrients were performed by USF MS student Caitlyn Parente. See the Supplemental File: 929305_v1_measured_and_certified_RMNS_results.csv and 929305_v1_measured_and_certified_RMNS_results_summary.csv for these figures and summary statistics.

Problems/Issues

No problems or issues were reported with this dataset.

Data Processing Description

Data were flagged using the SeaDataNet quality flag scheme recommended by GEOTRACES (https://www.geotraces.org/geotraces-quality-flag-policy/) and described below. Notes specific to the application of these flags to this dataset are noted in brackets […].

0: No Quality Control: No quality control procedures have been applied to the data value. This is the initial status for all data values entering the working archive. [Not used].

1: Good Value: Good quality data value that is not part of any identified malfunction and has been verified as consistent with real phenomena during the quality control process. [See Table 1 for blank and certified reference material values obtained in this study].

2: Probably Good Value: Data value that is probably consistent with real phenomena, but this is unconfirmed or data value forming part of a malfunction that is considered too small to affect the overall quality of the data object of which it is a part. [Used when no replicate measurements were available to check the quality of the data].

3: Probably Bad Value: Data value recognized as unusual during quality control that forms part of a feature that is probably inconsistent with real phenomena. [Used when all replicate measurements were too high to be consistent with real phenomena].

4: Bad Value: An obviously erroneous data value. [Not used].

5: Changed Value: Data value adjusted during quality control. Best practice strongly recommends that the value before the change be preserved in the data or its accompanying metadata. [Not used].

6: Value Below Detection Limit: The level of the measured phenomenon was less than the limit of detection (LOD) for the method employed to measure it. The accompanying value is the detection limit for the technique or zero if that value is unknown. [Values below detection are reported as 0.00 µM in the data file. Detection limits for each parameter are listed in the “methods and sampling” section of this form].

7: Value in Excess: The level of the measured phenomenon was too large to be quantified by the technique employed to measure it. The accompanying value is the measurement limit for the technique. [Not used].

8: Interpolated Value: This value has been derived by interpolation from other values in the data object. [Not used].

9: Missing Value: The data value is missing. Any accompanying value will be a magic number representing absent data [When sample was not collected the notation ‘na’ for ‘not applicable’ was used; when sample collected but there is no result for this parameter, the notation ‘NDA’ for ‘no data available’ was used].

A: Value Phenomenon Uncertain: There is uncertainty in the description of the measured phenomenon associated with the value such as chemical species or biological entity. [Not used.]

BCO-DMO Processing

- Spaces from column names replaced with underscores ("_")
- Special characters in column names replaced with plain text (i.e., "%" has been replaced with "percent")
- Date formats converted from %m/%d/%y to %Y-%m-%d
- Column "ISO_DateTime_UTC" created by merging the DATE_UTC and TIME_UTC columns

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-2326719

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
AE2305	STING I Cruise	2023-02-18	R/V Atlantic Explorer	Angela N. Knapp (Chief Scientist)	data info

Instruments

Discrete water sampler

Supplied Name: Towfish

Supplied Description:

Seawater samples were collected with a custom surface sampling system, “towfish” (Mellett and Buck 2020), comprised of acid cleaned Bev-A-Line-IV tubing and an Almatec Double PTFE Diaphragm Pump.

Instrument Type

Generic Name: Discrete water sampler

Generic Description:

A device that collects an in-situ discrete water sample from any depth and returns it to the surface without contamination by the waters through which it passes, such as a water bottle.

Niskin bottle

Supplied Name: 12-L X-Niskin bottles (Ocean Test Equipment)

Supplied Description:

12-L trace metal clean modified X-Niskin bottles (Ocean Test Equipment) mounted on a trace metal clean rosette with a programmable autofire module (Seabird) and deployed on 1/4” 12-strand Spectra synthetic line to collect depth profile seawater samples.

Instrument Type

Generic Name: Niskin bottle

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0412/

Generic Description:

A Niskin bottle (a next generation water sampler based on the Nansen bottle) is a cylindrical, non-metallic water collection device with stoppers at both ends. The bottles can be attached individually on a hydrowire or deployed in 12, 24, or 36 bottle Rosette systems mounted on a frame and combined with a CTD. Niskin bottles are used to collect discrete water samples for a range of measurements including pigments, nutrients, plankton, etc.

Nutrient Autoanalyzer

Supplied Name: QuAAtro39 AutoAnalyzer (SEAL Analytical)

Supplied Description:

QuAAtro39 AutoAnalyzer (SEAL Analytical) was used to measure macronutrient concentrations in seawater samples.

Instrument Type

Generic Name: Nutrient Autoanalyzer

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB04/

Generic Description:

Nutrient Autoanalyzer is a generic term used when specific type, make and model were not specified. In general, a Nutrient Autoanalyzer is an automated flow-thru system for doing nutrient analysis (nitrate, ammonium, orthophosphate, and silicate) on seawater samples.

Pump

Supplied Name: TM Pump

Supplied Description:

Wilden Pro-Flo Series P100 PTFE Diaphram Pump was deployed on 1/4” 12-strand Spectra synthetic line to collect surface and depth profile seawater samples at stations with water depth <50 m.

Instrument Type

Generic Name: Pump

Generic Description:

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

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
EVTNBR	Event number; ‘nda’ for ‘no data available’ or missing information; ‘na’ for ‘not applicable’ to that sample.	unitless	event
ISO_DateTime_UTC	UTC datetime when sample was collected. Format: %Y-%m-%dT%H:%MZ	unitless	DateTime
DATE_UTC	UTC date when sample was collected. Format: %Y-%m-%d	unitless	date
TIME_UTC	UTC time when sample was collected, in format HH:MM; ‘nda’ for ‘no data available’ or missing information; ‘na’ for ‘not applicable’ to that sample. Format: %H:%M	unitless	time
DATE_GMT	GMT date when sample was collected. Format: %Y-%m-%d	unitless	date
TIME_GMT	GMT time when sample was collected, in format HH:MM; ‘nda’ for ‘no data available’ or missing information; ‘na’ for ‘not applicable’ to that sample. Format: %H:%M	unitless	time
LATITUDE	Position when sample was collected in decimal decimal degrees, where a positive value indicates a Northern coordinate; ‘nda’ for ‘no data available’ or missing information; ‘na’ for ‘not applicable’ to that sample.	decimal degrees	lat
LONGITUDE	Position when sample was collected in decimal degrees where positive values represent an Eastern coordinate; ‘nda’ for ‘no data available’ or missing information; ‘na’ for ‘not applicable’ to that sample.	decimal degrees	lon
PLATFORM	Sampling system used. TMC CTD = trace metal CTD rosette. FISH = tow fish. TM PUMP = trace metal pump. INC = incubation.	unitless	platform
CASTNBR	Cast number; ‘na’ for ‘not applicable’ to that sample.	unitless	cast
STNNBR	Station number; ‘na’ for ‘not applicable’ to that sample.	unitless	sta_id
BTLNBR	CTD rosette bottle number; ‘na’ for ‘not applicable’ to that sample.	unitless	bot
DEPTH	Sample collection depth below sea surface; ‘no data available’ or missing information; ‘na’ for ‘not applicable’ to that sample.	meters (m)	depth
NO3_NO2	Concentrations of dissolved nitrate+nitrite.	micromoles per liter (uM)	NO3_NO2
NO3_NO2_STDEV	Standard deviation of replicate nitrate+nitrite concentration measurements. If only 2 replicates, the difference about the mean was used to calculate error.	micromoles per liter (uM)	NO3_NO2
NO3_NO2_FLAG	Quality flag for NO3_NO2. Refer to the Data Processing Description for more details about flags.	unitless	q_flag
PO4	Concentrations of dissolved phosphate.	micromoles per liter (uM)	PO4
PO4_STDEV	Standard deviation of replicate phosphate concentration measurements. If only 2 replicates, the difference about the mean was used to calculate error.	micromoles per liter (uM)	PO4
PO4_FLAG	6 = below the limit of detection.	unitless	q_flag
SiO4	Concentrations of dissolved silicate.	micromoles per liter (uM)	SiO4
SiO4_STDEV	Standard deviation of replicate silicate concentration measurements. If only 2 replicates, the difference about the mean was used to calculate error.	micromoles per liter (uM)	SiO4
SiO4_FLAG	Quality flag for SiO4.	unitless	q_flag
NO2	Concentrations of dissolved nitrite.	micromoles per liter (uM)	NO2
NO2_STDEV	Standard deviation of replicate nitrate+nitrite concentration measurements. If only 2 replicates, the difference about the mean was used to calculate error.	micromoles per liter (uM)	NO2
NO2_FLAG	Quality flag for NO2.	unitless	q_flag
STING_ID	need from submitter	unitless	no_bcodmo_term
NO3_NO2_percentRSD	Percent relative standard deviation of replicate nitrate+nitrite concentration measurements. Calculated as NO3_NO2_STDEV divided by NO3_NO2 and multiplied by 100; ‘na’ for ‘not applicable’, used when value of 0 assigned to concentrations <LOD.	unitless	NO3_NO2
PO4_percentRSD	Percent relative standard deviation of replicate phosphate concentration measurements. Calculated as PO4_STDEV divided by PO4 and multiplied by 100; ‘na’ for ‘not applicable’, used when value of 0 assigned to concentrations <LOD.	unitless	PO4
SiO4_percentRSD	Percent relative standard deviation of replicate silicate concentration measurements. Calculated as SiO4_STDEV divided by SiO4 and multiplied by 100.	unitless	SiO4
NO2_percentRSD	Percent relative standard deviation of replicate nitrite concentration measurements. Calculated as NO2_STDEV divided by NO2 and multiplied by 100; ‘na’ for ‘not applicable’, used when value of 0 assigned to concentrations <LOD.	unitless	NO2

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Dataset: STING macronutrient concentrations