%0 Journal Article %J Estuarine, Coastal and Shelf Science %D 2019 %T Assessing the ecological status of an estuarine ecosystem: linking biodiversity and food-web indicators %A Le Guen, Camille %A Samuele Tecchio %A Jean-Claude Dauvin %A De Roton, G. %A Lobry, Jeremy %A Lepage, Mario %A Morin, Jocelyne %A Géraldine Lassalle %A Raoux, Aurore %A Nathalie Niquil %K Biodiversity %K bioindicator %K community composition %K ecological approach %K ecological modeling %K ecosystem function %K ecosystem health %K environmental assessment %K estuarine ecosystem %K food web %K France %K habitat management %K health status %K human activity %K Le Havre %K Normandie %K Seine Estuary %K Seine Maritime %X During the last decades, the highly-anthropized Seine estuary has been impacted by modification of its habitats (building of a major extension of Le Havre harbour, i.e. Port2000) and a significant natural decrease in freshwater discharge. A Before/After analysis, using a toolbox of indicators, was applied to characterize the effects of both events on the estuarine ecosystem status. We selected from existing tool boxes several indicators derived from food web modelling or community composition data, such as biodiversity indicators, a guild-based index (i.e. Estuarine and Lagoon Fish Index ELFI) and ecological network analysis (ENA) indices. ENA and biodiversity indicators were applied on six spatial boxes describing the Seine estuary and its outlet. Results showed an increase in taxonomic and functional richness over time, mainly due to marinisation, and significant changes in food-web properties in relation to Port2000. ENA indices appeared as a promising method in ecological status assessment, especially for estuaries considered as inherently disturbed. © 2019 Elsevier Ltd %B Estuarine, Coastal and Shelf Science %I Academic Press %V 228 %G eng %U https://www.sciencedirect.com/science/article/abs/pii/S0272771419300484 %R 10.1016/j.ecss.2019.106339 %0 Journal Article %J Ecological indicators %D 2017 %T Benthic and fish aggregation inside an offshore wind farm: Which effects on the trophic web functioning? %A Raoux, Aurore %A Samuele Tecchio %A Pezy, Jean-Philippe %A Géraldine Lassalle %A Degraer, Steven %A Wilhelmsson, Dan %A Cachera, Marie %A Ernande, Bruno %A Le Guen, Camille %A Haraldsson, Matilda %A Karine Grangeré %A Le Loc'h, Francois %A Dauvin, Jean-Claude %A Nathalie Niquil %X

As part of the energy transition, the French government is planning the construction of three offshore wind farms in Normandy (Bay of Seine and eastern part of the English Channel, north-western France) in the next years. These offshore wind farms will be integrated into an ecosystem already facing multiple anthropogenic disturbances such as maritime transport, fisheries, oyster and mussel farming, and sediment dredging. Currently no integrated, ecosystem-based study on the effects of the construction and exploitation of offshore wind farms exists, where biological approaches generally focused on the conservation of some valuable species or groups of species. Complementary trophic web modelling tools were applied to the Bay of Seine ecosystem (to the 50 km(2) area covered by the wind farm) to analyse the potential impacts of benthos and fish aggregation caused by the introduction of additional hard substrates from the piles and the turbine scour protections. An Ecopath ecosystem model composed of 37 compartments, from phytoplankton to seabirds, was built to describe the situation ``before{''} the construction of the wind farm. Then, an Ecosim projection over 30 years was performed after increasing the biomass of targeted benthic and fish compartments. Ecological Network Analysis (ENA) indices were calculated for the two periods, ``before{''} and ``after{''}, to compare network functioning and the overall structural properties of the food web. Our main results showed (1) that the total ecosystem activity, the overall system omnivory (proportion of generalist feeders), and the recycling increased after the construction of the wind farm; (2) that higher trophic levels such as piscivorous fish species, marine mammals, and seabirds responded positively to the aggregation of biomass on piles and turbine scour protections; and (3) a change in keystone groups after the construction towards more structuring and dominant compartments. Nonetheless, these changes could be considered as limited impacts of the wind farm installation on this coastal trophic web structure and functioning. (C) 2016 Elsevier Ltd. All rights reserved.

%B Ecological indicators %V 72 %P 33-46 %8 01/2017 %G eng %R 10.1016/j.ecolind.2016.07.037