A novel statistical approach, regions of common profile (RCP), coupled with annual, randomised trawl surveys conducted in Heard Island and McDonald Islands (HIMI) waters of less than 1000m has previously been used to quantify the distribution of demersal fish assemblages across the Kerguelen Plateau (Hill et al. 2017). However, given that some species’ exhibit ontogenetic movement, are sexually dimorphic when mature, and have varying vulnerabilities to anthropogenic activities we extended this work by: (i) segregating species’ counts based on demographic parameters, and (ii) testing hypotheses related to climate change, fisheries and spatial management. Furthermore, we were able to incorporate a substantially longer time-frame (i.e., 15+ years) and update the suite of variables used to characterise habitat. We present results on the composition, environmental characteristics and distribution of demersal fish assemblages around HIMI. We discuss how explicitly incorporating demographics provides additional insights into our understanding of these assemblages. We also discuss how this information can assist ecosystem-based fisheries management in the region and contribute to monitoring within the HIMI Marine Reserve.