Large-scale coastal modifications are ubiquitous feature of urbanised cities that can fundamentally change seascapes. Understanding the impacts of coastal development on fishes is an urgent and critical knowledge gap. In this study, we seek to quantify the interactions of key coastal fish species with large-scale coastal modifications. Stereo baited remote underwater video systems were used to sample all major natural habitats and artificial structures in Gamay (Botany Bay) and Jervis Bay. Fish diversity, relative abundance and sizes were sampled to quantify differences in the fish assemblages among habitat types and distance from habitats. In particular, we assess the fundamental patterns of juvenile and adult occurrence on these various natural and artificial habitats. Within Gamay, fish assemblages varied greatly among habitats, with greater species richness and abundances (e.g. snapper) on rocky reefs and artificial structures, lower on soft sediment and seagrass. Species richness and abundances (of several species) reduced rapidly with distance from artificial structures. Distinct differences of various size-classes of fishes were observed among habitats within Gamay. Further analyses are underway to assess these patterns in Jervis Bay. This will be used to infer potential disruption caused by coastal modification to the utilisation of the seascape by fishes.