DOI: 10.5061/dryad.x69p8czsj
title: Long-term changes in taxonomic and functional composition of European marine fish communities

description: Evidence of large-scale biodiversity degradation in marine ecosystems has
 been reported worldwide, yet most research has focused on few species of
 interest or on limited spatiotemporal scales. Here we assessed the spatial
 and temporal changes in the taxonomic and functional composition of fish
 communities in European seas over the last 25 years (1994-2019). We then
 explored how these community changes were linked to environmental
 gradients and fishing pressure. We show that the spatial variation in fish
 species composition is more than two times higher than the temporal
 variation, with a marked spatial continuum in taxonomic composition and a
 more homogenous pattern in functional composition. The regions warming the
 fastest are experiencing an increasing dominance and total abundance of
 r-strategy fish species (lower age of maturity). Conversely, regions
 warming more slowly show an increasing dominance and total abundance of
 K-strategy species (high trophic level and late reproduction). Among the
 considered environmental variables, sea surface temperature, surface
 salinity, and chlorophyll-a most consistently influenced communities’
 spatial patterns, while bottom temperature and oxygen had the most
 consistent influence on temporal patterns. Changes in communities’
 functional composition were more closely related to environmental
 conditions than taxonomic changes. Our study demonstrates the importance
 of integrating community-level species traits across multi-decadal scales
 and across a large region to better capture and understand ecosystem-wide
 responses and provides a different lens on community dynamics that could
 be used to support sustainable fisheries management.
description: # Long-term changes in taxonomic and functional composition of European
 marine fish communities The GitHub linked repository is here:
 [European_demersal_fish_assemblages
 (](https://github.com/auroreRECE/European_demersal_fish_assemblages)DOI
 [10.5281/zenodo.11190119](https://zenodo.org/doi/10.5281/zenodo.11190119))
 ## Overview This project is dedicated to studying the influence of
 environmental conditions and fishing on the functional and taxonomic
 structure of a demersal fish community in Europe. This GitHub repository
 provides the code of the Receveur et al. (2024) publication in Ecography.
 ## Data files description ### df\_MFA.csv This file contains the
 coordinates resulting from the Multiple Factor Analysis (MFA): * X : the
 row numbers ; * ID_unique : a unique ID number corresponding to the trawls
 ; * Dim.1 : the coordinate of each trawl on the first MFA dimension ; *
 Dim.2 : the coordinate of each trawl on the second MFA dimension ; * Dim.3
 : the coordinate of each trawl on the third MFA dimension ; ###
 df\_PCA.csv This file contains the coordinates * X : the row numbers ; *
 ID_unique : a unique ID number corresponding to the trawls ; * Dim.1 : the
 coordinate of each trawl on the first PCA dimension ; * Dim.2 : the
 coordinate of each trawl on the second PCA dimension ; * Dim.3 : the
 coordinate of each trawl on the third PCA dimension ; ### df\_env.csv This
 file contains the following environmental parameters: * X : the row
 numbers ; * ID_unique : a unique ID number corresponding to the trawls ; *
 Year : the Year of each trawl ; * Quarter : the Quarter of each trawl ; *
 Ecoregion : the Ecoregion where each trawl has been done; * Survey : the
 name of the Survey ; * x_my_spatial_id : the longitude of the ICES
 rectangle where the trawl has been done ; * y_my_spatial_id : the latitude
 of the ICES rectangle where the trawl has been done ; * my_spatial_id : an
 ID for the ICES rectangle where the trawl has been done ; * depth : the
 bottom depth (meters) ; * depth_span : the bottom depth variability
 (maximum depth of the ICES cell - minimum depth) (meters) ; * chloro_mea:
 the mean chlorophyll-a concentration (mg/m³) ; * mlotst_mea : the mean
 mixed layer depth (meters) ; * oxy_bottom_mea : the mean bottom dissolved
 oxygen (umol/l) ; * oxy_surf_mea : the mean surface dissolved oxygen
 (umol/l) ; * temp_bottom_mea : the mean bottom temperature (°C) ; *
 temp_surf_mea : the mean surface temperature (°C) ; * curr_surf_mea : the
 mean surface current strength (m/s) ; * curr_bottom_mea : the mean bottom
 current strength (m/s) ; * sal_surf_mea : the mean surface salinity (PSU)
 ; * chloro_std : the standard deviation of chlorophyll-a concentration
 (mg/m³) ; * mlotst_std : the standard deviation of mixed layer depth
 (meters) ; * oxy_bottom_std : the standard deviation of bottom dissolved
 oxygen (umol/l) ; * oxy_surf_std : the standard deviation of surface
 dissolved oxygen (umol/l) ; * temp_bottom_std : the standard deviation of
 bottom temperature (°C) ; * temp_surf_std : the standard deviation of
 surface temperature (°C) ; * curr_surf_std : the standard deviation of
 surface current strength (m/s) ; * curr_bottom_std : the standard
 deviation of bottom current strength (m/s) ; * sal_surf_std : the standard
 deviation of surface salinity (PSU). ## Raw Data sources ### Biological
 data Trawls content is publicly available for the North East Atlantic
 (DATRAS database). Mediterranean data (MEDITS database) are available upon
 request to Maritime Affairs and Fisheries (MARE DATACOLLECTIONFRAMEWORK).
 The project uses the following surveys: | Survey Code | Survey name | Area
 | Period | References | | :---------- |
 :----------------------------------------------------- |
 :------------------------------------- | :-------: | :--------: | | BITS |
 Baltic International Trawl Survey | Baltic Sea | 1994-2019 | 4 | | BTS |
 Beam Trawl Survey | Celtic Sea; English Channel; North Sea | 1997-2019 | 7
 | | BTS-VIII | Beam Trawl Survey – Bay of Biscay | Bay of Biscay |
 2011-2019 | 7 | | DWS | Deepwater Survey | Irish Sea | 2006-2007 | 8 | |
 DYFS | Inshore Beam Trawl Survey | Southern North Sea | 2002-2019 | 7 | |
 EVHOE | French Southern Atlantic Bottom trawl Survey | Bay of Biscay and
 Celtic Sea | 2003-2019 | 1 | | FR-CGFS | French Channel ground Survey |
 English Channel | 1997-2019 | 2 | | IE-IAMS | Irish Anglerfish and megrim
 Survey | Scottish rockall and Irish Sea | 2016-2019 | 2 | | IE-IGFS |
 Irish Groundfish | Ireland Shelf Sea | 2003-2019 | 2 | | MEDITS |
 International bottom trawl survey in the Mediterranean | Mediterranean Sea
 | 1994-2018 | 9 | | NIGFS | Northern Ireland Groundfish Survey | Irish Sea
 | 2009-2019 | 2 | | NS-IBTS | North Sea International Bottom Trawl Survey
 | North Sea | 1997-2019 | 2 | | PT-IBTS | Portuguese International Bottom
 Trawl Survey | Portugal Shelf Sea | 2003-2017 | 2 | | ROCKALL | Scottish
 Rockall Survey (until 2010) | Rockall plateau | 2003-2009 | 2 | | SCOROC |
 Scottish Rockall Survey (from 2011) | Scottish plateau | 2011-2019 | 2 | |
 SCOWCGFS | Scottish West Coast Groundfish Survey | Scottish west coast |
 2011-2019 | 2 | | SNS | Sole Net Survey | Southern North Sea | 2002-2019 |
 7 | | SP-ARSA | Spanish Gulf of Cadiz Bottom Trawl Survey | Spain |
 2003-2019 | 6 | | SP-NORTH | Spanish North Bottom Trawl Survey | North of
 Spain | 2003-2019 | 2 | | SP-PORC | Spanish Porcupine Bottom Trawl Survey
 | Irish Sea | 2003-2019 | 5 | | SWC-IBTS | Scottish West Coast
 International Bottom Trawl Survey | Scotland Shelf Sea | 1999-2010 | 2 |
 ### Trait data The complete traits data table is available upon request.
 It is a combination of the publicly available PANGAEA database, Fishbase
 information, and inference based on the FISHLIFE project. ###
 Environmental variables The data used are all publicly available on the
 Copernicus website. ### Fishing data The data used are all publicly
 available on the Global Fishing Watch website. ## Recommended Citation
 Please use the following citation: Receveur, A., Leprieur F., Ellingsen
 K., Keith D., Kleisner K., McLean M., Mérigot B., Mills K., Mouillot D.,
 Rufino M., Trindade-Santos I., Van Hoey G., Albouy C., Auber A. Data for
 “Long-term changes in taxonomic and functional composition of European
 marine fish communities.” Dryad Digital Repository.
 (2024). doi.org/10.5061/dryad.x69p8czsj ## Acknowledgments This research
 is a product of the MAESTRO group funded by the synthesis center CESAB of
 the French Foundation for Research on Biodiversity (FRB). We thank France
 Filière Pêche (FFP) who founded the MAESTRO project. We also warmly thank
 all those who have contributed in any way to the scientific surveys and
 data collection/provision (European Institutions and scientists implicated
 in DATRAS-BTS, MEDITS, and DCF). ## References 1. ICES. The EVHOE survey
 (France). ICES Documents. (1997). Available at:
 https://archimer.ifremer.fr/doc/00036/14707/12013.pdf 2. ICES. Manual of
 the IBTS North Eastern Atlantic Surveys. Series of ICES Survey Protocols
 SISP 15 (2017). doi:10.17895/ices.pub.3519 3. ICES. Manual for the
 International Bottom Trawl Surveys Revision VIII. Series of ICES Survey
 Protocols SISP 10 - IBTS IX. (2015). 4.
 https://ices-library.figshare.com/articles/report/SISP_7_-*Manual_for_the_Baltic_International_Trawl_Surveys_BITS*/19050986 5. https://gis.ices.dk/geonetwork/srv/api/records/ce94a257-c8b3-44f7-9fd0-6bd7449ce073 6. http://ices.dk/sites/pub/CM%20Doccuments/2002/D/D0302A.pdf 7. https://ices-library.figshare.com/articles/report/SISP_14_-*Manual_for_the_Offshore_Beam_Trawl_Surveys_WGBEAM*/19051328 8. https://gis.ices.dk/geonetwork/srv/api/records/936b4fb7-9baa-4dbc-abd0-b1b7bda16406 9. https://archimer.ifremer.fr/doc/00117/22783/20585.pdf