Australia has one of the world’s largest Exclusive Economic Zones, yet its marine invertebrate biodiversity remains poorly understood—apparently only about 32% of species have been described. Much of this fauna spanning environments from tropical to sub-Antarctic waters is likely endemic. Despite this, taxonomic expertise is declining: state museums are losing specialist positions, and universities are no longer teaching taxonomy, even though accurate species identification underpins all biological research and environmental management. Over the past two decades, Australia has established extensive Commonwealth marine parks based largely on physical, habitat, and fisheries data. However, benthic communities—highly diverse and ecologically important—have been largely overlooked in their design and monitoring. These communities are essential to ecosystem function but remain poorly documented. Without greater recognition of their importance by management agencies, funding for taxonomic research will remain limited. Meanwhile, international efforts—often supported by industry and philanthropy—are advancing the study of benthic biodiversity. Australia risks falling behind. Here in Australia, strengthening taxonomic capacity and investing in large-scale biodiversity programs are critical. Without this knowledge, it is impossible to protect ecosystems, to assess whether marine management strategies are effective, or respond to threats such as invasive species and offshore development.