Global sampling decline erodes science potential of natural history collections.

The world's natural history collections hold over two billion specimens, representing a unique spatial and taxonomic record of biodiversity on Earth over time. In recent decades, the accessibility and value of collections data have grown through specimen digitisation, enhanced connectivity, and enriched information from new genotyping and digital trait extraction. These advances are expanding the relevance of collections beyond taxonomy and evolutionary biology to fields like environmental monitoring, agriculture, biosecurity, and public health. However, their utility for addressing major global challenges relies on mobilising legacy data and continuing specimen collection and digitisation. Here we show substantial declines in the rates of collection of specimen data over recent decades, from analysis of over 150 million records from the Global Biodiversity Information Facility (GBIF) spanning more than two centuries. The degree and timing of decline varies across taxonomic groups and geographical regions. Overall, these findings suggest that the value of natural history collections as global research infrastructure is eroding due to decreased collecting of specimen data across species, locations, and time. This is occurring precisely when applications for these data have never been more important, and advances in data analytics, AI and genomics promise to unlock deeper insights from natural history collections.