Surface abrasion of seabeds by bottom contacting fishing gears - Mediterranean Sea (surface Swept Area Ratio)

Data on physical impact intensity caused by trawling (bottom otter trawl, twin bottom otter trawl, dredges) estimated from VMS (Vessel Monitoring System) data cross-referenced with the Community Fishing Fleet Register and, for French vessels, with the landing data between 2008 and 2020. The data is constituted of 14 rasters in a resolution of 1’x1’ (13 annual abrasion rasters between 2008 and 2020 and 1 raster representing the 90th percentile of inter-annual abrasion). The abrasion is expressed in swept area ratio per year for each layer. This work enabled the study of the trawling impact on benthic communities in the Gulf of Lions and Corsica. The objective was to better describe the spatial and temporal repartition of trawling in this area and its potential impact on benthic habitats.
 
Citation proposal
Jac Cyrielle Jac Cyrielle (IFREMER IFREMER ) - Vaz Sandrine Vaz Sandrine (IFREMER IFREMER ). Surface abrasion of seabeds by bottom contacting fishing gears - Mediterranean Sea (surface Swept Area Ratio). IFREMER IFREMER https://services.mspdata.eu:/geonetwork/srv/api/records/8bed2328-a0fa-4386-8a3e-d6d146cafe54

Simple

Date ( Creation )
2020-06-01
Identifier
FR-330-715-368-00032-IFR_MARBEC_Surf_SAR_MED_FR
Identifier
DOI:10.12770/8bed2328-a0fa-4386-8a3e-d6d146cafe54
Credit
This work was supported by the IDEM (EU), Benthchal (EC2CO) projects and the Occitanie region

  Author

  Author

  Publisher

Thèmes Sextant Thèmes Sextant ( Theme )
  • /Human Activities/Recreational Fishing
GEMET - INSPIRE themes, version 1.0 GEMET - INSPIRE themes, version 1.0 ( Theme )
  • Habitats and biotopes
Sous-regions marines Sous-regions marines ( Place )
  • Western Mediterranean
Cadre Réglementaire - SIMM Cadre Réglementaire - SIMM ( Theme )
  • Directive Cadre Stratégie pour le Milieu Marin (DCSMM)
Thématiques - SIMM Thématiques - SIMM ( Theme )
  • /Activités et Usages/Pêche et Aquaculture , /Etat du Milieu/Habitats
Type de jeux de donnée ODATIS Type de jeux de donnée ODATIS ( Theme )
  • /Processed data/Composite products
DCSMM : Descripteurs DCSMM : Descripteurs ( Theme )
  • D6: Sea-floor Integrity , D1: Coastal benthic habitats , D1: Biodiversité - Poissons , D1: Fish and Cephalopods
Ocean Hackathon - Ville Ocean Hackathon - Ville ( Place )
  • Toulon
Use limitation
Données sous Licence Creative Commons - Attribution + Pas d’Utilisation Commerciale + Partage dans les mêmes conditions (BY-NC-SA) : http://creativecommons.fr/licences/
Access constraints
Other restrictions
Use constraints
Copyright
Other constraints
Spatial representation type
Grid
Distance
0.0166667  degree
Metadata language
French
Character set
UTF8
Topic category
  • Imagery base maps earth cover
N
S
E
W


Reference system identifier
EPSG / WGS 84 (EPSG:4326) / 8.6
Distribution format
  • ( )

OnLine resource
Publication 1  

Eigaard Ole R., Bastardie Francois, Breen Mike, Dinesen Grete E., Hintzen Niels T., Laffargue Pascal, Mortensen Lars O., Nielsen J. Rasmus, Nilsson Hans C., O'Neill Finbarr G., Polet Hans, Reid David G., Sala Antonello, Skold Mattias, Smith Chris, Sorensen Thomas K., Tully Oliver, Zengin Mustafa, Rijnsdorp Adriaan D. (2016). Estimating seabed pressure from demersal trawls, seines, and dredges based on gear design and dimensions . Ices Journal Of Marine Science , 73, 27-43. https://doi.org/10.1093/icesjms/fsv099

OnLine resource
The footprint of bottom trawling in European waters: distribution, intensity, and seabed integrity  

Ole R. Eigaard, Francois Bastardie, Niels T. Hintzen, Lene Buhl-Mortensen, Pål Buhl-Mortensen, Rui Catarino, Grete E. Dinesen, Josefine Egekvist, Heino O. Fock, Kerstin Geitner, Hans D. Gerritsen, Manuel Marín González, Patrik Jonsson, Stefanos Kavadas, Pascal Laffargue, Mathieu Lundy, Genoveva Gonzalez-Mirelis, J. Rasmus Nielsen, Nadia Papadopoulou, Paulette E. Posen, Jacopo Pulcinella, Tommaso Russo, Antonello Sala, Cristina Silva, Christopher J. Smith, Bart Vanelslander, Adriaan D. Rijnsdorp, Handling editor: Michel Kaiser; The footprint of bottom trawling in European waters: distribution, intensity, and seabed integrity, ICES Journal of Marine Science, Volume 74, Issue 3, 1 March 2017, Pages 847–865, https://doi.org/10.1093/icesjms/fsw194

OnLine resource
Surf_SAR_MED_FR_P90_08_2020  

Swept Area Ratio - Méditerranée - 2008 à 2020

Protocol
COPYFILE
Name
Surf_SAR_MED_FR_P90_08_2020
Description
Swept Area Ratio - Méditerranée - 2008 à 2020
OnLine resource
Surf_SAR_MED_FR_2008  

Swept Area Ratio - Méditerranée - 2008

Protocol
COPYFILE
Name
Surf_SAR_MED_FR_2008
Description
Swept Area Ratio - Méditerranée - 2008
OnLine resource
Surf_SAR_MED_FR_2009  

Swept Area Ratio - Méditerranée - 2009

Protocol
COPYFILE
Name
Surf_SAR_MED_FR_2009
Description
Swept Area Ratio - Méditerranée - 2009
OnLine resource
Surf_SAR_MED_FR_2010  

Swept Area Ratio - Méditerranée - 2010

Protocol
COPYFILE
Name
Surf_SAR_MED_FR_2010
Description
Swept Area Ratio - Méditerranée - 2010
OnLine resource
Surf_SAR_MED_FR_2011  

Swept Area Ratio - Méditerranée - 2011

Protocol
COPYFILE
Name
Surf_SAR_MED_FR_2011
Description
Swept Area Ratio - Méditerranée - 2011
OnLine resource
Surf_SAR_MED_FR_2012  

Swept Area Ratio - Méditerranée - 2012

Protocol
COPYFILE
Name
Surf_SAR_MED_FR_2012
Description
Swept Area Ratio - Méditerranée - 2012
OnLine resource
Surf_SAR_MED_FR_2013  

Swept Area Ratio - Méditerranée - 2013

Protocol
COPYFILE
Name
Surf_SAR_MED_FR_2013
Description
Swept Area Ratio - Méditerranée - 2013
OnLine resource
Surf_SAR_MED_FR_2014  

Swept Area Ratio - Méditerranée - 2014

Protocol
COPYFILE
Name
Surf_SAR_MED_FR_2014
Description
Swept Area Ratio - Méditerranée - 2014
OnLine resource
Surf_SAR_MED_FR_2015  

Swept Area Ratio - Méditerranée - 2015

Protocol
COPYFILE
Name
Surf_SAR_MED_FR_2015
Description
Swept Area Ratio - Méditerranée - 2015
OnLine resource
Surf_SAR_MED_FR_2016  

Swept Area Ratio - Méditerranée - 2016

Protocol
COPYFILE
Name
Surf_SAR_MED_FR_2016
Description
Swept Area Ratio - Méditerranée - 2016
OnLine resource
Surf_SAR_MED_FR_2017  

Swept Area Ratio - Méditerranée - 2017

Protocol
COPYFILE
Name
Surf_SAR_MED_FR_2017
Description
Swept Area Ratio - Méditerranée - 2017
Protocol
COPYFILE
Name
Surf_SAR_MED_FR_2018
Description
Swept Area Ratio - Méditerranée - 2018
Protocol
COPYFILE
Name
Surf_SAR_MED_FR_2019
Description
Swept Area Ratio - Méditerranée - 2019
Protocol
COPYFILE
Name
Surf_SAR_MED_FR_2020
Description
Swept Area Ratio - Méditerranée - 2020
OnLine resource
DOI du jeu de donnée  

DOI du jeu de donnée

OnLine resource
Surf_SAR_MED_FR_2018  

Swept Area Ratio - Méditerranée - 2018

OnLine resource
Surf_SAR_MED_FR_2019  

Swept Area Ratio - Méditerranée - 2019

OnLine resource
Surf_SAR_MED_FR_2020  

Surf_SAR_MED_FR_2020

Hierarchy level
Dataset

Conformance result

Date ( Publication )
2010-12-08
Explanation
See the referenced specification
Statement
This work attempts to approximate the approach used by Eigaard et al (2016-2017) based on aggregated VMS data on a 1'x1' grid.
Description
The raw data used were produced by Ifremer’s SIH (Système d’Information Halieutique) AlgoPesca procedure in order to keep only positions corresponding to fishing operations (non-null speed <= 4 kts, away from return harbour routes). Data was expressed in number of fishing hours and aggregated in 1’x1’ grid by flag, month, size class of vessel and gear type (corresponding to landing declarations or main fishing gear recorded in the Community Fishing Fleet Register.
Rationale
Description

Abrasion depending on both vessel speed and type of gear used, different values of speed or horizontal trawl opening were attributed according to vessel’s length and flag thanks to bibliography, law regulations and experts’ knowledge (local trawl manufacturers, trawl owners and captains and fishery organization representatives). In the case of dredges (French ; ≤ 15m) speed was set at 3kt and opening to 4m before 2013 (included) and 3m after (JORF 2013; https://www.legifrance.gouv.fr/eli/arrete/2013/4/12/TRAM1309072A/jo/texte/fr ). Speed of Italian vessels was also set at 3 kts and the horizontal trawl opening was estimated following Eigaard et al. (2016). Thus, Italian trawling had a horizontal trawl opening range between 77 m and 50 m depending on vessels’ length :

- ≥ 24 m : 77 m

- ]18-24] : 72 m

- ]15-18] : 58 m

- ]12-15] : 50 m

For all French and Spanish vessels < 24m, speed was set at 3.5 kt and at 4 kt for vessels equal or larger than 24m.

Horizontal trawl opening for Spanish vessels was fixed to 100m regardless their length. French twin-rig otter trawls used on vessel large or equal to 24 m were set vith a horizontal trawl opening of 110 m and vessels between 18 and 24m had a 95m opening. Other French bottom otter trawls opening range between 100 and 55 m depending on the vessel length :

- ≥ 24 m : 100 m

- ]18-24] : 75 m

- ]15-18] : 55 m

- ≤ 15 m : 55 m

Distance traveled by each vessel category inside a 1'x1' cell was determined by multiplying the speed of the ship by the number of hour spent in the cell. The area swept by each vessel was calculated for each cell by multiplying the distance traveled by the horizontal trawl opening (or dredge width). Ratio between cell‘s swept area and cell surface allows to obtain the abrasion caused by each flag/vessel length/gear type in each cell per month (Eigaard et al. 2016, 2017). These abrasions are summed by cell over each year to get an annual abrasion value for each cell. Inter-annual 90th percentile was calculated for each cell allowing to get a spatial representation of the maximum abrasion values experienced in the study area over a 10-year period, while avoiding extreme values or outliers.

Rationale

Metadata

File identifier
8bed2328-a0fa-4386-8a3e-d6d146cafe54   XML
Metadata language
French
Character set
UTF8
Hierarchy level
Dataset
Date stamp
2021-06-14T12:05:09
Metadata standard name
ISO 19115:2003/19139 - SEXTANT
Metadata standard version
1.0

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