Metadata: Identification_Information: Citation: Citation_Information: Originator: Nancy G. Prouty Publication_Date: 20250717 Title: Water and algal chemistry measurements collected from the National Park Service's National Park of American Samoa (NPS-NPSA) Ofu Island unit Geospatial_Data_Presentation_Form: comma-delimited text Series_Information: Series_Name: data release Issue_Identification: DOI: 10.5066/P1DVZPUV Publication_Information: Publication_Place: Pacific Coastal and Marine Science Center, Santa Cruz, California Publisher: U.S. Geological Survey Other_Citation_Details: Suggested Citation: Prouty, N.G., 2025, Water and algal chemistry measurements collected from the National Park Service's National Park of American Samoa (NPS-NPSA) Ofu Island unit: U.S. Geological Survey data release, https://doi.org/10.5066/P1DVZPUV. Online_Linkage: https://doi.org/10.5066/P1DVZPUV Description: Abstract: Geochemical analysis of coastal springs and possible source waters were conducted in the National Park Service's National Park of American Samoa (NPS-NPSA) Ofu Island unit. Water samples were analyzed for dissolved nutrients, nitrate isotopes (delta-18-O and delta-15-N). Algae samples were collected and analyzed for delta-15-N and delta-13-C values. Purpose: These samples were collected and analyzed as part of an effort to characterize the spatiotemporal variability of nutrient-enriched submarine groundwater (SGD) in NPSA. This project focused on identifying and quantifying the composition and fluxes of submarine groundwater discharged onto the reef. These results will inform help NPS-NPSA staff and local government to direct remediation actions related to outbreak of Valonia fastigiata algae. Supplemental_Information: Additional information about the field activity or activities from which these data were derived is available online at: http://cmgds.marine.usgs.gov/fan_info.php?fan=2020-601-FA http://cmgds.marine.usgs.gov/fan_info.php?fan=2020-620-FA http://cmgds.marine.usgs.gov/fan_info.php?fan=2020-670-FA Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20190705 Ending_Date: 20200209 Currentness_Reference: Ground condition at time data were collected. Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -169.6767950 East_Bounding_Coordinate: -169.6216050 North_Bounding_Coordinate: -14.1850000 South_Bounding_Coordinate: -14.1715070 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: oceans Theme_Keyword: environment Theme_Keyword: geoscientificInformation Theme: Theme_Keyword_Thesaurus: Data Categories for Marine Planning Theme_Keyword: Water-Quality Parameters Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: geochemistry Theme_Keyword: light stable isotope analysis Theme_Keyword: chemical analysis Theme: Theme_Keyword_Thesaurus: Marine Realms Information Bank (MRIB) keywords Theme_Keyword: coral reefs Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: U.S. Geological Survey Theme_Keyword: USGS Theme_Keyword: Coastal and Marine Hazards and Resources Program Theme_Keyword: CMHRP Theme_Keyword: Pacific Coastal and Marine Science Center Theme_Keyword: PCMSC Theme_Keyword: nutrients Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:67cf4de3d34ecfe34cc86a5b Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: Pacific Ocean Place_Keyword: Ofu Island Place_Keyword: Territory of American Samoa Place: Place_Keyword_Thesaurus: NGA GEOnet Names Server (GNS) Place_Keyword: Papaloloa Place_Keyword: Fattuana Access_Constraints: No access constraints Use_Constraints: USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey, and the National Park Service (NPS) as the originators of the dataset and in products derived from these data. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Person: PCMSC Science Data Coordinator Contact_Address: Address_Type: mailing and physical Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-427-4747 Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov Data_Set_Credit: Brendan Roark (Texas A&M) and Danielle Hull (University of Hawaii) completed the stable isotope analysis and nutrient analysis, respectively. Native_Data_Set_Environment: Mac OS 11.4, Microsoft Excel 16.52 for Mac. Cross_Reference: Citation_Information: Originator: D.M. Sigman Originator: K.L. Casciotti Originator: M. Andreani Originator: C. Barford Originator: M. Galanter Originator: J.K. Bohlke Publication_Date: 2001 Title: A bacterial method for the nitrogen isotopic analysis of nitrate in seawater and freshwater Online_Linkage: http://pubs.acs.org/doi/pdf/10.1021/ac010088e Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: All geochemistry data were calibrated against known standards Logical_Consistency_Report: No formal logical accuracy tests were conducted. Completeness_Report: Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the metadata for each part of this data release carefully for additional details. Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the metadata for each part of this data release carefully for additional details. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: A formal accuracy assessment of the horizontal positional information in the data set has not been conducted. The horizontal accuracy is based on hand-held Garmin GPS. Horizontal accuracy is approximately 3 meters. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: A formal accuracy assessment of the vertical positional information in the data set has not been conducted. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: University of California, Davis Stable Isotope Facility Publication_Date: 2020 Title: nitrate stable nitrogen isotope analysis Type_of_Source_Media: seawater lab samples Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20200913 Source_Currentness_Reference: Date when lab analyses were completed Source_Citation_Abbreviation: Nitrate delta-N-15 and delta-O-18 Source_Contribution: Denitrifier method of Sigman and others, (2001) using a Thermo Finnigan MAT 252 coupled with a GasBench II interface, isotope values are presented in per mil with respect to AIR for delta-N-15 and VSMO for delta-O-18 Source_Information: Source_Citation: Citation_Information: Originator: University of Hawaii, School of Ocean and Earth Science and Technology (SOEST) Publication_Date: 2020 Title: nutrient analysis Online_Linkage: http://www.soest.hawaii.edu/S-LAB/slab_prices.htm Type_of_Source_Media: water lab samples Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20200408 Source_Currentness_Reference: Date when lab analyses were completed Source_Citation_Abbreviation: nutrient analysis Source_Contribution: Nutrient autoanalyzer for analysis for dissolved nutrient (nitrate, ammonia, phosphate, and silicate) concentrations. Source_Information: Source_Citation: Citation_Information: Originator: Texas A&M University Publication_Date: 2020 Title: nutrient analysis Online_Linkage: http:// stableisotope.tamu.edu Type_of_Source_Media: algae lab samples Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20200723 Source_Currentness_Reference: Date when lab analyses were completed Source_Citation_Abbreviation: Stable isotope analysis Source_Contribution: Nitrogen (delta-N-15) and Carbon (delta-C-13) analysis on algae samples. Process_Step: Process_Description: Discrete water sampling included pumping from coastal springs at low tide and a groundwater well, marsh, and cesspool using a peristaltic pump with an in-line 0.45-micron filter and grab samples from the nearshore and reef flat by filtering with a 0.20-mircron syringe filter and storing frozen until analysis. Water samples were analyzed by several different labs (see Sources) for different variables. Data from all lab analyses were combined into a single document. -9999 cell value indicates no data (for example, where water sample was not analyzed for a particular variable given sample volume limitations). Algae samples were collected by snorkel, stored frozen, freeze dried at the lab, and homogenized prior to lab analysis for delta-N-15 and delta-C-13. Source_Used_Citation_Abbreviation: nutrient analysis Source_Used_Citation_Abbreviation: Nitrate delta-N-15 and delta-O-18 Source_Used_Citation_Abbreviation: Stable isotope analysis Process_Date: 2020 Source_Produced_Citation_Abbreviation: lab data Process_Step: Process_Description: Water and algae data were combined into a single document (Ofu_water_algal_chemistry.csv). Source_Used_Citation_Abbreviation: lab data Process_Date: 2020 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Point Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Point Point_and_Vector_Object_Count: 112 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.00000001 Longitude_Resolution: 0.0000001 Geographic_Coordinate_Units: Decimal degrees Geodetic_Model: Horizontal_Datum_Name: D_WGS_1984 Ellipsoid_Name: D_WGS_1984 Semi-major_Axis: 6378137.000000 Denominator_of_Flattening_Ratio: 298.257224 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: Ofu_water_algal_chemistry.csv Entity_Type_Definition: Output from chemical analysis of water and algae samples Entity_Type_Definition_Source: Producer defined. Attribute: Attribute_Label: Sample ID Attribute_Definition: Sample identification of sampled based on location (Ofu), site (CS=coastal spring, CP=cesspool, WL=well, MS=marsh, FR=forereef) or sample type (algae), sequential number and year of collection. Attribute_Definition_Source: Producer defined Attribute_Domain_Values: Unrepresentable_Domain: List of station names Attribute: Attribute_Label: Date Attribute_Definition: Sample collection date Attribute_Definition_Source: Producer defined. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 2019-07-05 Range_Domain_Maximum: 2020-02-09 Attribute_Units_of_Measure: YYYY-MM-DD Attribute: Attribute_Label: Time Attribute_Definition: Sample collection time (GMT-11). Values of -9999 indicate the parameter was not measured. Attribute_Definition_Source: Producer defined. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 7:26 Range_Domain_Maximum: 19:15 Attribute_Units_of_Measure: Hour:minutes Attribute: Attribute_Label: Latitude Attribute_Definition: Latitude of sample location Attribute_Definition_Source: Producer defined. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -14.18533201 Range_Domain_Maximum: -14.17150700 Attribute_Units_of_Measure: decimal degrees Attribute_Measurement_Resolution: 0.00000001 Attribute: Attribute_Label: Longitude Attribute_Definition: Longitude of sample location Attribute_Definition_Source: Producer defined. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -169.6767950 Range_Domain_Maximum: -169.6216050 Attribute_Units_of_Measure: decimal degrees Attribute_Measurement_Resolution: 0.000001 Attribute: Attribute_Label: Salinity Attribute_Definition: Measured salinity of water sample. Values of -9999 indicate the parameter was not measured. Attribute_Definition_Source: Producer defined. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.1 Range_Domain_Maximum: 35.0 Attribute_Units_of_Measure: parts per thousand Attribute_Measurement_Resolution: 0.1 Attribute: Attribute_Label: Temperature Attribute_Definition: Measured temperature of water sample. Values of -9999 indicate the parameter was not measured. Attribute_Definition_Source: Producer defined. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 25.5 Range_Domain_Maximum: 29.4 Attribute_Units_of_Measure: degrees Celsius Attribute_Measurement_Resolution: 0.1 Attribute: Attribute_Label: Phosphate Attribute_Definition: Dissolved inorganic phosphate concentration. Values of -9999 indicate the parameter was not measured. Attribute_Definition_Source: standard reporting value in inorganic chemistry Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.16 Range_Domain_Maximum: 340.18 Attribute_Units_of_Measure: micromole per liter of seawater Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: Silicate Attribute_Definition: Dissolved inorganic silicate concentration. Values of -9999 indicate the parameter was not measured Attribute_Definition_Source: standard reporting value in inorganic chemistry Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.91 Range_Domain_Maximum: 1203.85 Attribute_Units_of_Measure: micromole per liter of seawater Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: Nitrate and nitrite Attribute_Definition: Dissolved inorganic nitrate and nitrite concentration. Values of -9999 indicate the parameter was not measured Attribute_Definition_Source: standard reporting value in inorganic chemistry Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.37 Range_Domain_Maximum: 52.83 Attribute_Units_of_Measure: micromole per liter of seawater Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: Ammonium Attribute_Definition: Dissolved inorganic Ammonium concentration. Values of -9999 indicate the parameter was not measured. Values of -8888 indicate that the compound was not detected. Attribute_Definition_Source: standard reporting value in inorganic chemistry. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.02 Range_Domain_Maximum: 2783.34 Attribute_Units_of_Measure: micromole per liter of seawater Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: delta-N-15 Attribute_Definition: delta-N-15 is a measure of the ratio of stable isotopes Nitrogen-15:Nitrogen-14, reported in parts per thousand (per mil). Values of -9999 indicate the parameter was not measured. Attribute_Definition_Source: standard reporting value in inorganic chemistry. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -9.75 Range_Domain_Maximum: 9.77 Attribute_Units_of_Measure: per mil Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: delta-O-18 Attribute_Definition: delta-O-18 is a measure of the ratio of stable isotopes Oxygen-18:Oxygen-16 in water, reported in parts per thousand (per mil). Values of -9999 indicate the parameter was not measured. Attribute_Definition_Source: Producer defined. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -1.79 Range_Domain_Maximum: 4.84 Attribute_Units_of_Measure: per mil Attribute: Attribute_Label: Percent organic nitrogen Attribute_Definition: Percentage by weight (wt percent) of organic nitrogen; values of -9999 indicate the parameter was not measured. Attribute_Definition_Source: Producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.68 Range_Domain_Maximum: 2.77 Attribute_Units_of_Measure: percent weight Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: delta-C-13 Attribute_Definition: delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12 in water, reported in parts per thousand (per mil). Values of -9999 indicate the parameter was not measured. Attribute_Definition_Source: Producer defined. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -20.95 Range_Domain_Maximum: -5.18 Attribute_Units_of_Measure: per mil Attribute: Attribute_Label: Percent organic carbon Attribute_Definition: Percentage by weight (wt percent) of organic carbon; values of -9999 indicate the parameter was not measured. Attribute_Definition_Source: Producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 5.52 Range_Domain_Maximum: 10.59 Attribute_Units_of_Measure: percent weight Attribute_Measurement_Resolution: 0.01 Overview_Description: Entity_and_Attribute_Overview: The first line of the csv file is a header line. Entity_and_Attribute_Detail_Citation: U.S. Geological Survey Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - ScienceBase Contact_Address: Address_Type: mailing and physical Address: Denver Federal Center, Building 810, Mail Stop 302 City: Denver State_or_Province: CO Postal_Code: 80225 Contact_Voice_Telephone: 1-888-275-8747 Contact_Electronic_Mail_Address: sciencebase@usgs.gov Resource_Description: These data are available in a comma-delimited text file (Ofu_water_algal_chemistry.csv) which contains water and algae analysis. Distribution_Liability: Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: comma-separated text Format_Version_Number: 16.52 Format_Information_Content: comma-delimited text File_Decompression_Technique: none Transfer_Size: 0.03702 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/67cf4de3d34ecfe34cc86a5b Network_Resource_Name: https://doi.org/10.5066/P1DVZPUV Access_Instructions: Data can be downloaded using the Network_Resource_Name links. The first link is a direct link to download the zipped file of data and metadata. The second link points to the landing page for the entire data release. Fees: None. Technical_Prerequisites: These data can be viewed with any text editor software. Metadata_Reference_Information: Metadata_Date: 20250717 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Person: PCMSC Science Data Coordinator Contact_Address: Address_Type: mailing and physical Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-427-4747 Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998