Development of a new sampling methodology of benthic invertebrates on a restored braided river

Braided rivers are dynamic hydrosystems characterised by a multiple channels morphology and a marked hydrology with high amplitude variations and high diversity of macro-, meso-and microhabitats: channel types, geomorphic units and flowing conditions. After the WFD publication¹ and the objective to achieve good ecological status, restoration operations increased. In this context, several indices are used to assess the good ecological status. However, in the case of the benthic invertebrate index, the methodology is based on a general sampling method adapted to all river types, which is not adapted to the specificities of the braided morphology. We developed a new sampling methodology of benthic invertebrates that better accounts for habitat diversity. We hypothesise that the consideration of the habitats diversity, through several spatial scales, allows a better representation of the benthic invertebrates community.