Comparison of independently derived benthic invertebrate and demersal fish ecoregionalisations for the Kerguelen Plateau

Ecoregionalisation is a process that aims to identify areas with distinct biological content and associated environmental conditions. It improves on many traditional approaches to regionalisation by explicitly incorporating biological data into classifications. Ecoregionalisations are useful for improving our ecological understanding of marine ecosystems and for informing spatial management. This includes providing information to aid in defining and prioritising areas for conservation, evaluating current spatial management arrangements, targeting monitoring efforts and managing human activities (e.g. Grant et al., 2006; Douglass et al., 2014). The Kerguelen Plateau is a highly productive region of the southern Indian Ocean that supports lucrative demersal fisheries (Duhamel and Welsford, 2011). It is subject to spatial management in the form of marine protected areas (MPAs) with varying levels of protection (Commonwealth of Australia, 2014; Koubbi et al., 2016). Recently two ecoregionalisations have been independently generated for the northern Kerguelen Plateau; one for benthic invertebrates (Martin et al., 2018) and another for demersal fish (Hill et al., 2017). Here we conduct a preliminary analysis examining the congruence between these ecoregionalisations that represent different components of the demersal ecosystem.