Influence of 'bouchot' mussel culture on the benthic environment in a dynamic intertidal system

Abstract

The present study examines the influence of mussel aquaculture structures (bouchots) in the intertidal zone of the Chausey Archipelago (Normandy, France) where strong tidal currents are predicted to disperse biodeposits. Six sites were sampled to determine the spatial variability of organic matter content, sediment grain size, and benthic infaunal community characteristics. The influence of bouchots on the benthic environment was evident at both the mesoscale (i.e. km-scale, between farm and reference sites) and small-scale (i.e. m-scale, spatial structure within farms but not reference sites). This influence was also apparent for sediment grain size distribution and most metrics of macrobenthic community structure, but not for sediment organic matter. Mussel culture structures likely modify natural flow patterns within farm sites, which increases shear stress around individual bouchots, thereby increasing the heterogeneity of benthic communities, altering the dominance of particular species within farms and differentiating them from reference sites. © Inter-Research 2012.