The 4.4 ha Horsburgh Drive Grassland Reserve in Altona was established to a protect a large population of the critically endangered Golden Sun-moth and the critically endangered Natural Temperate Grassland of the Victorian Volcanic Plain ecological community. Biosis, together with Grey Box and Grasslands Indigenous Nursery (GAGIN), has been assisting Hobson’s Bay City Council with the ongoing monitoring and management of this important reserve, which is situated within an industrial estate. Since its establishment, on-ground achievements include a significant reduction in the extent of the weed Chilean Needle-grass, the virtual eradication of hares and rabbits and a regime of regular biomass reduction to improve grassland structure. Biosis has also assisted GAGIN to re-establish a range of locally extinct grassland plants through supplementary planting. Most recently, the reserve has benefited from the installation of an interpretative sign, highlighting its value as Golden Sun-moth habitat.