Impact of the construction of the MRE platform in the semi-enclosed Bay bordering the English Channel ("Rade de Cherbourg") on benthic habitat and geomorphology - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2023

Impact of the construction of the MRE platform in the semi-enclosed Bay bordering the English Channel ("Rade de Cherbourg") on benthic habitat and geomorphology

Impact de la construction de nouveaux terre-pleins portuaires EMR sur les habitats benthiques et la géomorphologie de la rade de Cherbourg

Résumé

The Cherbourg roadstead has been radically altered by the installation of industrial infrastructures (major dredging and reclamation works in 2015 and 2016 to allow the passage of deeper-draught ships and the creation of a new quay: 39 ha). A research program was carried out before and after the transformation of the port platforms to improve knowledge of the roadstead and assess its impact. Three complementary environmental approaches were used: (1) morphological changes based on a comparison of bathymetric data; (2) changes in sediment cover based on granulometric data; and (3) the impact on macrofauna benthic communities. It appears that the new construction is the cause of a morphological change in the seabed, leading to the creation of multi-metric "hollows" and "humps", responsible for a general change in hydrodynamics and widespread silting of the Grand Rade (+14% silt). To the east, more than 10% of the well-sorted, unimodal sandy seabed has silted up after the extension. This siltation reduced the exceptional diversity of benthic habitats and has led to a drastic reduction in fragile species (amphipods) and an increase in opportunistic species, probably altering the entire structure of the food web.
Fichier non déposé

Dates et versions

hal-04264301 , version 1 (30-10-2023)

Identifiants

  • HAL Id : hal-04264301 , version 1

Citer

Noémie Baux, Gwendoline Gregoire, Régis Gallon, Anne Murat, Yann Méar, et al.. Impact of the construction of the MRE platform in the semi-enclosed Bay bordering the English Channel ("Rade de Cherbourg") on benthic habitat and geomorphology. COAST2023, Oct 2023, Caen, France. ⟨hal-04264301⟩
28 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More