Ecoregionalisation and conservation of benthic communities in the French exclusive economic zone of Kerguelen

The deep-sea benthic ecosystems of the French Kerguelen exclusive economic zone remain poorly understood. To address benthic conservation issues, the authors recently contributed expert knowledge to guide the recent extension of the Marine Reserve of the ‘Terres australes françaises’. In this new study, we propose a benthic ecoregionalisation of the northern Kerguelen Plateau based on a measurable and repeatable methodology that relies on the generalised dissimilarity modelling technique. Data of macro-epibenthic invertebrate species from the POKER 2 (2010) fish stock assessment survey have been used to compute the models. Our results allow us (i) to characterise and map benthic landscape units based on assemblages of marine invertebrates pooled by taxa and life-history traits, (ii) to highlight the environmental drivers of the spatial distribution of benthic assemblages, (iii) to assess the relevance of the CCAMLR’s vulnerable marine ecosystems bioindicator taxa, and (iv) to assess the effectiveness of ‘strictly protected areas’ of the new Marine Reserve for the conservation of deep-sea benthic ecosystems.