Slide Menu
Search Help Show/Hide Menu
Short Citation:
Office for Coastal Management, 2023: Nitrate Mean Concentration,

Item Identification

Title: Nitrate Mean Concentration
Status: Completed

Nutrient data were obtained from the Bio-ORACLE project and represent a long-term composite of data from 2000 to 2014. The map layer represents mean nitrate concentration (micromoles per liter) in surface waters of the U.S. Exclusive Economic Zone. Additional data available for download here provide six nutrient concentrations at three different depths within the water column (surface, mean depth, and maximum depth). Data have a common spatial resolution of 5 arc minutes and were assessed using a cross‐validation framework against in situ quality‐controlled data.


To support ocean planning activities pursuant to the Executive Order Regarding the Ocean Policy to Advance the Economic, Security, and Environmental Interests of the United States, the Energy Policy Act, the National Environmental Policy Act, the Rivers and Harbors Act, and the Coastal Zone Management Act.


Theme Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Science Keywords
ISO 19115 Topic Category
ISO 19115 Topic Category
ISO 19115 Topic Category
ISO 19115 Topic Category
None alternative energy planning
None biogeographic
None coastal energy planning
None ecosystem
None environment
None environmental
None environmental energy planning
None farming
None marine cadastre
None marine spatial planning
None modeled
None nitrate
None nutrient
None ocean
None ocean energy planning
None offshore energy planning
None planningCadastre
None renewable energy planning

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords
None Alaska
None Atlantic
None East Coast
None Gulf of Mexico
None Hawaii
None Pacific
None United States
None West Coast

Physical Location

City: Charleston
State/Province: SC

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: As Needed
Data Presentation Form: Map (digital)
Distribution Liability:

Data Set Credit: NOAA Office for Coastal Management, NOAA National Centers for Coastal Ocean Science, Bureau of Ocean Energy Management

Support Roles

Point of Contact

CC ID: 1115702
Date Effective From: 2020-06
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202


Currentness Reference: Publication Date

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1115712
W° Bound: -180
E° Bound: 180
N° Bound: 74.75
S° Bound: -17.58305555556

Access Information

Security Class: Unclassified
Data Use Constraints:

For coastal and ocean planning

Distribution Information

Distribution 1

CC ID: 1121323
Download URL:
Description: Data Registry

Distribution 2

CC ID: 1115704
Download URL:

Technical Environment


Esri ArcGIS

Data Quality


The attributes in this dataset are believed to be accurate.

Horizontal Positional Accuracy:

Maximum scale of intended use is 1:80,000.

Completeness Report:

Spatial and attribute properties are believed to be complete, although attribute information has been simplified. Geometric thresholds from original data are preserved. No tests have been completed for exhaustiveness.

Conceptual Consistency:

These data are believed to be logically consistent. Geometry is topologically clean.



Bio-ORACLE: Marine Data Layers for Ecological Modelling

CC ID: 1115709
Contact Role Type: Publisher
Contact Type: Organization
Contact Name: Bio-ORACLE
Extent Type: Discrete
Extent Start Date/Time: 2020-02-01
Citation URL:
Citation URL Name: Source Online Linkage
Citation URL Description:

URL where the source data were originally accessed.

Source Contribution:

Provided modeled nitrate data at depth for the US EEZ.

Process Steps

Process Step 1

CC ID: 1115710

1) Data sets were derived from Bio‐ORACLE (ocean rasters for analysis of climate and environment) global data set.

2) Nitrate concentrations (micromoles per litre) are reported as six statistical measures including Lt. Max, Lt. Min, Min, Max, mean, and range over three depths (surface, mean, maximum). *Lt. (long-term) for average of the minimum and maximum records per year (e.g., temperature of the warmest month, on average). For the Marine Cadastre National Viewer, only the mean surface depth concentration is displayed as an example.

3) The Bio-ORACLE “Present data set” (2000 - 2014) was downloaded as Tiff Raster files (.tif) using Bio-ORACLE’s download manager.

4) This surface and benthic layers, for each of the three nutrients were then entered as a geodatabase into ArcGIS 10.7. Each .tif file was then clipped to the United States Exclusive Economic Zone (EEZ) using the EEZ shapefile.

5) Data were then given a continuous color schema to avoid issues with color-blind audiences (e.g. red to green) over the range of data values for each statistical measure. The lighter shade of a color represents areas with lower nitrate concentrations relative to the darker shades where higher nitrate values occur.

6) Surface, mean, and maximum concentration values were QA/QC’ed for any elements lacking in the data description or attributes, illogical values, spatial accuracy, and overall consistency across the data within the US EEZ.

7) Each data layer was then projected to WGS 1984 Web Mercator Auxiliary Sphere (EPSG: 3857) projection

8) Permission to use this data was received from the authors prior to use in Comparisons were also made to the ESRI Ecological Marine Unit (EMU) nutrient data where spatial overlap occurred, to ensure likeness in data over geographical space.

9) The Bio-ORACLE data are modeled and have been statistically downscaled and therefore have inherit biases associated with these types of analyses occur. However, methodology implemented here create a more spatially resolved data set for nutrients in US waters than any other known by the authors. However, these data lack high temporal resolution.

10) While the Bio-Oracle Nutrient data may have higher horizontal spatial resolution, the Esri EMU data has higher number of depth levels (102 depth levels). There are pros and cons of both data sets and users are recommended to compare the data sets before deciding which is best for their own analyses.

11) The pros to the ESRI EMU nutrient data is data are present over 102 depth levels, and can be used to statistically differentiate different portions of the water column. The cons lie its course spatial resolution, no temporal component, and no nearshore values (as of 2020). Sayre et al. (2019) ( ) are working towards coastal EMUs, which will increase the spatial coverage of the EMU data. It is recommended that users view the pros and cons of applying the various data sets (Bio-ORACLE vs. EMU) to their own analyses.

More information about methodology used can be found in these resources:

Assis, J., Tyberghein, L., Bosh, S., Verbruggen, H., Serrão, E. A., & De Clerck, O. (2017). Bio-ORACLE v2.0: Extending marine data layers for bioclimatic modelling. Global Ecology and Biogeography.

Tyberghein L, Verbruggen H, Pauly K, Troupin C, Mineur F, De Clerck O (2012) Bio-ORACLE: A global environmental dataset for marine species distribution modelling. Global Ecology and Biogeography, 21, 272–281.

Process Date/Time: 2020-01-01 00:00:00

Catalog Details

Catalog Item ID: 66153
GUID: gov.noaa.nmfs.inport:66153
Metadata Record Created By: Brianna Key
Metadata Record Created: 2021-12-22 04:16+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2023-05-30 18:10+0000
Metadata Record Published: 2021-12-22
Owner Org: OCM
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2021-12-22
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2022-12-22