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Seafloor litter - Spatial distribution of litter density normalized per km² 2011/2024 v2025

This visualization product displays the spatial distribution of seafloor litter density per trawl.



EMODnet Chemistry included the collection of marine litter in its 3rd phase. Since the beginning of 2018, data of seafloor litter collected by international fish-trawl surveys have been gathered and processed in the EMODnet Chemistry Marine Litter Database (MLDB).

The harmonization of all the data has been the most challenging task considering the heterogeneity of the data sources, sampling protocols (OSPAR and MEDITS protocols) and reference lists used on a European scale. Moreover, within the same protocol, different gear types are deployed during bottom trawl surveys.



In cases where the wingspread and/or number of items were/was unknown, it was not possible to use the data because these fields are needed to calculate the density. Data collected before 2011 are concerned by this filter.



When the distance reported in the data was null, it was calculated from:

- the ground speed and the haul duration using the following formula: Distance (km) = Haul duration (h) * Ground speed (km/h);

- the trawl coordinates if the ground speed and the haul duration were not filled in.



The swept area was calculated from the wingspread (which depends on the fishing gear type) and the distance trawled:

Swept area (km²) = Distance (km) * Wingspread (km)



Densities were calculated on each trawl and year using the following computation:

Density (number of items per km²) = ∑Number of items / Swept area (km²)



Then a grid with 30km x 30km cells was used to calculate the weighted mean of densities in each cell from the formula :

Weighted mean (number of items per km²) = ∑ (Distance (km) * Density (number of items per km²)) / ∑ Distance (km)



Percentiles 50, 75, 95 & 99 were calculated taking into account data for all years.



More information on data processing and calculation are detailed in the attached methodology document.



Warning: the absence of data on the map does not necessarily mean that they do not exist, but that no information has been entered in the Marine Litter Database for this area.



This work is based on the work presented in the following scientific article:

O. Gerigny, M. Brun, M.C. Fabri, C. Tomasino, M. Le Moigne, A. Jadaud, F. Galgani, Seafloor litter from the continental shelf and canyons in French Mediterranean Water: Distribution, typologies and trends, Marine Pollution Bulletin, Volume 146, 2019, Pages 653-666, ISSN 0025-326X, https://doi.org/10.1016/j.marpolbul.2019.07.030.

Simple

Alternate title

sl_spatialdistribution_totalabundance_30km

Date (Creation)
2025-02-27T00:00:00+01:00
Edition

1.0

Citation identifier
DOI:10.13120/0be49f9d-c763-4c0e-97e5-fb8b0e49731d
Credit

EMODnet Chemistry

Point of contact

No information provided.

Thèmes Sextant

  • /Human Activities/Pollution

GEMET - INSPIRE themes, version 1.0
  • Oceanographic geographical features
Parameter Discovery Vocabulary (P02)
  • Sea-floor litter abundance
  • Litter abundance and type
SeaVoX salt and fresh water body gazetteer
  • Black Sea
  • Arctic Ocean
  • Northeast Atlantic Ocean (40W)
  • North Sea
  • Mediterranean Sea
  • Baltic Sea
Theme
  • EMODnet Chemistry

Matrix Categories
  • sediment
EMODnet Chemistry chemical groups
  • Marine litter

Mission Atlantic - Resources

  • Data

Mission Atlantic - Case Studies

  • Celtic Seas

Mission Atlantic - Work Package

  • WP4 Benthic Mapping

Mission Atlantic - BODC Parameters

  • /Environment/Pollution

Mission Atlantic - Data type (DMP)

  • Spatial data products

Ocean Hackathon - City and challenge

  • /Boulogne-sur-Mer/BOL02

  • /Boulogne-sur-Mer/BOL04

  • /Boulogne-sur-Mer/BOL06

  • /Bournemouth/BOR01

  • /Concepción/CON06

  • /Kuala Lumpur/KUL08

  • /La Rochelle/LAR01

  • /Peniche/PEN01

  • /Brest

  • /Boulogne-sur-Mer

  • /Bournemouth

  • /Cherbourg

  • /La Rochelle

  • /Toulon

  • /Plymouth

Use limitation

CC BY 4.0: https://creativecommons.org/licenses/by/4.0/

Access constraints
unrestricted
Use constraints
Other restrictions
Other constraints

Usage is subject to mandatory citation: "This resource was generated in the framework of EMODnet Chemistry, under the support of DG MARE Call for Tender EASME/EMFF/2020/3.1.11/European Marine Observation and Data Network (EMODnet) - Lot 5 - Chemistry"

Spatial representation type
Vector
Language

eng

Topic category
  • Oceans
Description

bounding box

N
S
E
W
thumbnail




Begin date
2011-05-03
End date
2024-03-21

Vertical extent

Minimum value
-5500.0
Maximum value
0.0
Reference system identifier
EPSG / WGS 84 (EPSG:4326)
Geometric object type
Point
Distribution format
Name Version
OnLine resource
Protocol Linkage Name

OGC:WMS

https://sextant.ifremer.fr/services/wms/emodnet_chemistry2

sl_spatialdistribution_totalabundance_30km

WWW:LINK

https://sextant.ifremer.fr/documentation/emodnet_chemistry/document/Field_description/SL_field_description_spatialdistribution_totalabundance_30km.xlsx

Description of the layer's fields

WWW:DOWNLOAD

https://sextant.ifremer.fr/sextant_data/EMODNET/CHEMISTRY/MARINE_LITTER/2025/sl_spatialdistribution_totalabundance_30km.zip

Direct Download

WWW:LINK

https://emodnet.ec.europa.eu/geoviewer/

EMODnet Map Viewer

WWW:LINK

https://doi.org/10.1016/j.marpolbul.2019.07.030

Seafloor litter from the continental shelf and canyons in French Mediterranean Water: Distribution, typologies and trends

WWW:LINK

https://doi.org/10.13120/c622d045-94ed-4b6a-9c78-404e86b8b9a3.v1

Visualization products for seafloor litter data

WWW:LINK

https://dx.doi.org/10.6092/15c0d34c-a01a-4091-91ac-7c4f561ab508

Guidelines and forms for gathering marine litter data

DOI

https://doi.org/10.13120/0be49f9d-c763-4c0e-97e5-fb8b0e49731d

Digital Object Identifier (DOI)

Hierarchy level
Series

Conformance result

Title

COMMISSION REGULATION (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services

Date (Publication)
2010-12-08
Explanation

See the referenced specification

Statement

The original datasets can be searched and downloaded from EMODnet Chemistry Chemistry CDI Data and Discovery Access Service: https://cdi-chemistry.seadatanet.org/search

Metadata

File identifier
0be49f9d-c763-4c0e-97e5-fb8b0e49731d XML
Metadata language
English
Character set
UTF8
Hierarchy level
Series
Hierarchy level name

Product record

Date stamp
2025-04-25T08:29:29.444145Z
Metadata standard name

ISO 19115:2003/19139 - EMODNET - SDN

Metadata standard version

1.0

Metadata author
Organisation name Individual name Electronic mail address Role

EMODnet Chemistry

sextant@ifremer.fr

Point of contact
 
 

Overviews

overview

Spatial extent

thumbnail

Keywords

EMODnet Chemistry
EMODnet Chemistry chemical groups

Marine litter
GEMET - INSPIRE themes, version 1.0

Oceanographic geographical features
Matrix Categories

sediment
Mission Atlantic - BODC Parameters

/Environment/Pollution
Mission Atlantic - Case Studies

Celtic Seas
Mission Atlantic - Data type (DMP)

Spatial data products
Mission Atlantic - Resources

Data
Mission Atlantic - Work Package

WP4 Benthic Mapping
Parameter Discovery Vocabulary (P02)

Litter abundance and type Sea-floor litter abundance
SeaVoX salt and fresh water body gazetteer

Arctic Ocean Baltic Sea Black Sea Mediterranean Sea North Sea Northeast Atlantic Ocean (40W)
Thèmes Sextant

/Human Activities/Pollution


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