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Short Citation:
Office for Coastal Management, 2023: Ecological Marine Units: Nutrients,

Item Identification

Title: Ecological Marine Units: Nutrients
Status: Completed

A compilation of ocean nutrient (nitrate, phosphate, and silicate concentrations) data at ¼ degree spatial resolution for the entire United States Exclusive Economic Zone. The dataset is derived from the ESRI Ecological Marine Unit (EMU) dataset, which was assembled from non-supervised statistical clustering of over 52 million points from NOAA’s World Ocean Atlas (2013) WoA database, an authoritative 57 year archive of global water column data. This derived dataset is divided into three separate point shapefiles, each representing either nitrate, phosphate, or silicate concentrations (all in units of μmol l-1). Values for nutrient concentrations represent a climatological average. Each shapefile is formatted such that a single point location (i.e., unique associated latitude and longitude) contains a unique column entry for a given depth interval. Depth intervals are variable from 5 m near the surface to 100 m in the deeper regions (> 2000 m) for a total of 102 depth levels. All disclaimers provided by the original dataset authors apply to this derived dataset. For detail on these disclaimers, please refer to the following reference: Sayre, R., J. Dangermond, D. Wright, S. Breyer, K. Butler, K. Van Graafeiland, M.J. Costello, P. Harris, K. Goodin, M. Kavanaugh, N. Cressie, J. Guinotte, Z. Basher, P. Halpin, M. Monaco, P. Aniello, C. Frye, D. Stephens, P. Valentine, J. Smith, R. Smith, D.P. VanSistine, J. Cress, H. Warner, C. Brown, J. Steffenson, D. Cribbs, B. Van Esch, D. Hopkins, G. Noll, S. Kopp, and C. Convis. 2017. A New Map of Global Ecological Marine Units – An Environmental Stratification Approach. Washington, DC: American Association of Geographers. 36 pages.


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
ISO 19115 Topic Category
ISO 19115 Topic Category
None coastal
None planning
None renewable energy
None water column
None water quality

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords
None Exclusive Economic Zone
None Outer Continental Shelf
None Territorial Sea
None United States of America

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: Bureau of Ocean Energy Management, NOAA Office for Coastal Management, NOAA National Centers for Coastal Ocean Science, Esri

Support Roles

Point of Contact

CC ID: 1115239
Date Effective From: 2018-06
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: 1115248
W° Bound: -179.875
E° Bound: 179.875
N° Bound: 74.625
S° Bound: -17.375

Access Information

Security Class: Unclassified
Data Use Constraints:

For coastal and ocean planning

Distribution Information

Distribution 1

CC ID: 1115241
Download URL:

Distribution 2

CC ID: 1121196
Download URL:

Ocean Reports

Technical Environment


Version 6.2 (Build 9200) ; 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.



Esri Ecological Marine Unit (EMU) dataset for Nitrate

CC ID: 1115245
Contact Name: Esri
Extent Type: Discrete
Extent Start Date/Time: 2018-08-01
Citation URL:
Citation URL Name: Source Online Linkage
Citation URL Description:

URL where the source data were originally accessed.

Source Contribution:

Esri Ecological Marine Unit (EMU) dataset

Process Steps

Process Step 1

CC ID: 1115246

(1) ESRI Ecological Marine Units data clipped to the boundaries of the United States Exclusive Economic Zone were provided by Keith VanGraafeiland (ESRI). Data were provided in a large point shapefile format with multiple points associated with a single latitude and longitude location. Original attribute fields included those representing depth, unique ecological marine units, nutrients (nitrates, phosphates, silicates), temperature, salinity, dissolved oxygen, among other related fields. (2) Data were re-shaped into a single point shapefile for each nutrient parameter (i.e., nitrates, phosphates, silicates). These shapefiles contain a unique point representing each single latitude and longitude location. Each shapefile contains two unique identifier attributes: FID and QtrDegreeI. QtrDegreeI allows each unique point location to be referenced back to the original ESRI Ecological Marine Units Dataset. Attribute fields for nutrient concentrations at depth were added for each point within the shapefile. These fields were derived from the original dataset and represent nutrient concentrations within each depth interval (e.g., N_001-N_101 wherein N_001 represents nutrient concentrations for waters between 0 and 5 m depth).

Process Date/Time: 2018-08-01 00:00:00

Child Items

Rubric scores updated every 15m

Rubric Score Type Title
Entity Ecological Marine Units: Nutrients

Catalog Details

Catalog Item ID: 66135
GUID: gov.noaa.nmfs.inport:66135
Metadata Record Created By: Brianna Key
Metadata Record Created: 2021-12-22 03:24+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