Corey T Callaghan 

Human development and population growth are placing immense pressure on natural ecosystems, necessitating a balance between development and biodiversity preservation. Citizen science may serve as a valuable resource for monitoring biodiversity and informing decision-making processes, but its use has not been investigated within the realm of environmental review. We sought to quantify the extent to which citizen science data are currently being used, mentioned, or suggested in environmental impact statements (EISs) by analyzing a corpus of EISs (> 1,000) produced under the United States National Environmental Policy Act (NEPA), housed at NEPAccess.org. We found increasing incorporation of citizen science within the environmental review process, with 40% of EISs mentioning, using, or suggesting use of such information in 2022. Citizen science offers substantial potential to enhance biodiversity monitoring and conservation efforts within environmental review, but there are many considerations that need to be broadly discussed before widespread adoption.