Title

Global Distribution of Seagrasses (version 7.1). Seventh update to the data layer used in Green and Short (2003). Cambridge (UK)

Date (Revision)

2021-03-01

Date (Publication)

2015-01-01

Citation identifier

9e5e5d26-eea9-4729-a7bc-4f13223e0cf2

Abstract

This dataset shows the global distribution of seagrasses, and is composed of two subsets of point and polygon occurrence data. The data were compiled by UN Environment World Conservation Monitoring Centre in collaboration with many collaborators (e.g. Frederick Short of the University of New Hampshire), organisations (e.g. OSPAR), and projects (e.g. the European project Mediterranean Sensitive Habitats “Mediseh”), across the globe (full list available in accompanying metadata table within the dataset).

Purpose

This dataset was originally developed alongside the publication by Green and Short (2003), and was the first authoritative and comprehensive global synthesis of the spatial distribution and status of seagrasses.

Credit

UN Environment World Conservation Monitoring Centre

Point of contact

Organisation name	Individual name	Electronic mail address	Role
UN Environment Programme World Conservation Monitoring Centre		oceanplus@unep-wcmc.org	Publisher
UNEP-WCMC, Short FT		oceanplus@unep-wcmc.org	Author

Thèmes Sextant

• /Biological Environment/Habitats

GEMET - INSPIRE themes, version 1.0

• Habitats and biotopes

Mission Atlantic - Resources

• Data

Mission Atlantic - Case Studies

• Canary Current system

• Atlantic Ocean

Mission Atlantic - BODC Parameters

• /Biological oceanography/Macroalgae and seagrass

Mission Atlantic - Data type (DMP)

• Spatial data products

Mission Atlantic - Work Package

• WP3 Pelagic Mapping

• WP4 Benthic Mapping

• WP1 Atlantic Ocean IEA

Use limitation

UNEP-WCMC General Data License.

Other legal constraints

For commercial use, please contact business-support@unep-wcmc.org.

Spatial representation type

Vector

Denominator

1000000

Language

English

Character set

UTF8

Topic category

• Oceans

Begin date

1934-01-01

End date

2020-01-01Before

Unique resource identifier

EPSG:4326

Distribution format

Name	Version
ESRI Shapefile	1.0

OnLine resource

Protocol	Linkage	Name
WWW:LINK-1.0-http--metadata-URL	https://doi.org/10.34892/x6r3-d211	Global Distribution of Seagrasses
WWW:DOWNLOAD-1.0-link--download	https://wcmc.io/WCMC_013_014	Download data

Hierarchy level

Dataset

Statement

Version 7.1 (March 2021): ParentISO3, ISO3 (ISO 3166-3 character code of country and territory where the feature is located) and subISO3 (ISO 3166-2 sub-national code(s)) were removed.

Version 7.0 (October 2020): The dataset structure was reverted to Version 4.0, with single part features and a similar attribute list structure (see supplementary information). The following changes were made to the polygon dataset:

- Replaced 2 polygons of UAE data (ID# 445) with 4964 more accurate and up-date-data (ID# 574)

- Added 96 polygons to Watamu Bay in Kenya

- Added 66 Polygons in Portugal (Metadata ID # 576) from EMODnet Seabed data

- Added 113 Polygons in Ireland (Metadata ID #577) from EMODnet Seabed data

- Added 367 Polygons in Norway (Metadata ID #578) from EMODnet Seabed data

- Added 582 Polygons in the UK (Metadata ID #579) from EMODnet Seabed data

- Added 39 polygons in Spain (Metadata ID #580) from EMODnet Seabed data

- Removed 50 polygons in France (Metadata ID #491) and replaced them with 506 more detailed polygons in France from the EMODnet Seabed data; original map_ID FR003016 (Metadata ID #581)

- Added 18559 polygons in France (Metadata ID #581) from the EMODnet Seabed data

- Erased ID#490 USA data from a dataset formerly titled 491_Florida found in the Seagrass data sources folder with a 20-meter buffer. 937 Polygons remained that was so far missing from our dataset. These 937 polygons within Florida have been added as Metadata ID #489.

- Removed 5.916 polygons ID#491 and replaced them with 7.403 more accurately placed polygons ID#582 from EMODnet data in Italy

- Removed 4106 polygons ID#491 in Greece and replaced them with 4.495 more accurately placed polygons ID#583 from EMODnet data

- Delted 4 polygons with metadatID#418 in Italy and Malta, as those have been replaced with higher resolution data with Metadata ID #582 and #491

Version 6.0 (June 2018): Geographic attributions (ISO3 and Parent ISO3 codes) of points and polygons in the datasets have been matched to the World Vector Shoreline Plus and VLIZ World EEZ v10 geographic layers. This improves the accuracy of these datasets for national and regional studies. ISO3 codes need to be updated regularly due to codes becoming obsolete or EEZ boundaries being adjusted. Multipart points and polygons features were created to reduce the complexity of the attribute tables, merging those with identical attributes. This reduces the processing power required to handle the data while maintaining the level of detail required. The habitat datasets have been quality checked for obsolete ISO3 codes, overlapping claims identified and "Not reported" consistently used for missing values rather than NA or blanks.

Version 5 (December 2017): Standardises the feature and metadata attributes using a new schema, which aligns the attributes used across the habitat datasets curated by UNEP-WCMC. The updated attribute schema is outlined in

"Supplementary Information." Specific changes include the addition of information on the level of protection (e.g. PROTECT, PROTECT_FEAT, PROTECT_STAT), indication of whether the data have received expert or government verification (VERIF), and information on the start and end dates of data collection (i.e. START_DATE,END_DATE). The new schema will be used to inform a set of quality indicators, assessing changes in data quality over time. This dataset supersedes versions 3.0 and 4.0 of the seagrass dataset, which was an updated version of the dataset used in Green and Short (2003).

Version 4 (2016): The following changes were made to the dataset:

- Removed 69 polygons (approx. 708 sq km; ID #20) and replaced them with better Corsican data (ID #491);

- Added 19,327 polygons (approx. 11,184 sq km) of Posidonia seagrass in Europe, from the MEDISEH project (ID #491);

- Added 6,681 polygons (approx. 421 sq km) of seagrass in British Columbia (ID #492); Total spatial changes reflected in the polygon feature class: Removed 708 square kilometres (69 polygons) and added 1,297,092 hectares / 12,970 sq km (35,416 polygons). The seagrass extent (after dissolve by ISO3) is 344,958 sq km. The total change in the area between versions 3 and 4 (after dissolving by ISO3) is 7,950 sq km. Total changes to the point dataset include the addition of 8,887 data points.

Version 3.0 (2015): incorporated over 16,600 square kilometres of seagrass occurrence data obtained in October 2013 from the Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), and Coastal Services Center (CSC) of the United States. Once dissolved, total seagrass extent in version 3.0 equates 314,173 sq km (184,814 polygons).

- Added 9,211 polygons (approx. 1307 sq km) from OSPAR's 2015 habitat data (ID#495 -519);

- Incorporated 1 polygon from Malta (58.95 sq km) (ID #493);

- Incorporated 1,533 seagrass occurrence data points (not Posidonia) from MEDISEH (ID #494); and

- Added 7,227 seagrass occurrence data points from OSPAR's 2015 habitat data

Metadata

File identifier

9e5e5d26-eea9-4729-a7bc-4f13223e0cf2

Metadata language

English

Character set

UTF8

Hierarchy level

Dataset

Date stamp

2022-02-23T12:13:54.655Z

Metadata standard name

ISO 19115:2003/19139 - SEXTANT

Metadata standard version

1.0

Metadata author

Organisation name	Individual name	Electronic mail address	Role
Ifremer	Sextant	sextant@ifremer.fr	Local service desk