Megabenthic community sensitivity to bottom trawling and associated uncertainty

Three community-level indices of megabenthic invertebrate sensitivity to bottom trawling were calculated across the Mediterranean soft-bottoms:

- Community low-resistance index: reflects the likelihood that communities are captured or physically damaged by bottom trawling.

Biological traits considered: position within the sediment, mobility, adult size, and fragility.

- Community low-resilience index: reflects the limited recovery potential of communities following bottom-trawling disturbance.

Biological traits considered: feeding mode and longevity.

- Community sensitivity index: integrates both the low-resistance and low-resilience indices to provide an overall measure of community sensitivity to bottom trawling.

***These layers are associated with the report: Millot Jade, Vaz Sandrine, Lauria Valentina (2026). Sensitivity of megabenthic invertebrate communities to bottom trawling in the Mediterranean based on biological traits. RBE/MARBEC/LHM. https://doi.org/10.13155/117327***

Date (Publication): 2025-10-07

Identifier: https://sextant.ifremer.fr/record/a3d9c5cd-f415-42b5-bc38-60043b2d240f

Credit: Ifremer

Author

Ifremer - Jade Millot

Author

IFREMER - Vaz Sandrine ( PDG-DGDS-RBE-MARBEC-LHM )

04 99 57 32 12

Publisher

IFREMER - Sextant

Thèmes Sextant

/Milieu biologique/Habitats

GEMET - INSPIRE themes, version 1.0

Habitats et biotopes

Keywords

Use limitation: CC-BY (Creative Commons - Attribution)

Access constraints: Other restrictions

Use constraints: License

Other constraints: We do our best to ensure that the data is complete, accurate and useful. However, because the processing required to generate the data is complex, we cannot be liable for omissions or inaccuracies. The data and any related materials contained therein are provided “as is”, without warranty of any kind, either expressed or implied, including but not limited to, fitness for a particular purpose, non-interference, system integration, or non-infringement. The entire risk of use of the data shall be with the user.

Unique resource identifier: 10.17600/96060020

Association Type: Cross reference

Initiative Type: Platform

Unique resource identifier: da33d0b4-f208-4a85-bc62-478a2a7fdf68

Association Type: Larger work citation

Unique resource identifier: 10.13155/117327

Association Type: Cross reference

Initiative Type: Study

Unique resource identifier: seanoe:104981

Association Type: Larger work citation

Spatial representation type: grid Grid

Distance: 0.05 °

Metadata language: Français

Character set: utf8 UTF8

Topic category

Oceans
Environment

Begin date: 2012-01-01

End date: 2021-01-01

Unique resource identifier: EPSG:4326

Number of dimensions: 4

Dimension name: Time

Dimension name: Vertical

Dimension name: Column

Dimension size: 1075

Resolution: 0.05 °

Dimension name: Row

Dimension size: 400

Resolution: 0.05 °

Cell geometry: surface

Transformation parameter availability: No

Distribution format

Protocol: COPYFILE

Name: community_sensitivity

Description: Megabenthic community sensitivity to bottom trawling and associated uncertainty

Function: Download

OnLine resource: community_sensitivity_MEDITS ( OGC:WMS )
Community sensitivity index of megabenthic invertebrate sensitivity to bottom trawling

OnLine resource: community_low_resilience_MEDITS ( OGC:WMS )
Community low-resilience index of megabenthic invertebrate sensitivity to bottom trawling

OnLine resource: community_low_resistance_MEDITS ( OGC:WMS )
Community low-resistance index of megabenthic invertebrate sensitivity to bottom trawling

OnLine resource: community_sensitivity_uncertainties_MEDITS ( OGC:WMS )
Kriging uncertainty - Community sensitivity index of megabenthic invertebrate sensitivity to bottom trawling

OnLine resource: community_low_resilience_uncertainties_MEDITS ( OGC:WMS )
Kriging uncertainty - Community low-resilience index of megabenthic invertebrate sensitivity to bottom trawling

OnLine resource: community_low_resistance_uncertainties_MEDITS ( OGC:WMS )
Kriging uncertainty - Community low-resistance index of megabenthic invertebrate sensitivity to bottom trawling

OnLine resource: Digital Object Identifier (DOI) ( DOI )

Hierarchy level: Dataset

Domain consistency

Conformance result

Date (Publication): 2010-12-08

Explanation: See the referenced specification

Pass: No

Statement: 1- Megabenthic invertebrate taxa collected during the MEDITS survey were scored according to their sensitivity to bottom trawling, based on biological trait assessment informed by expert knowledge (e.g., position in the sediment, mobility, adult size, fragility, feeding mode, and longevity).

2- Biomass data (g/km²) were log-transformed to limit the influence of extreme values.

3- Three indices were calculated: “low-resistance” (RSI), “low-resilience” (RLI), and “sensitivity” (SI)

4- Community-Weighted Means of “low-resistance”, “low-resilience”, and overall “sensitivity” were calculated at each MEDITS station by weighting RSI, RLI, and SI scores, respectively, by the relative biomass of megabenthic taxa.

4- Semi-variogram optimization was performed by testing several combinations of initial parameters, including minimum and maximum separation lag, minimum and maximum separation distance, and stepwise increment. Three models were fitted, and the best model was selected based on three evaluation metrics: highest R², lowest mean absolute error (MAE), and lowest Akaike Information Criterion (AIC).

5- The index distributions were then interpolated using kriging based on the best-fitting semi-variogram model and rasterized to a finer resolution of 0.05°.

6- Kriging uncertainty was assessed by a measure of interpolation error (i.e., kriging variance): the initial resolution of 0.1° was kept for these products.

Further details on the data and methods can be found in the associated report.