Blitz the Gap: a nation-wide effort to guide citizen science toward the needs of biodiversity science

Katherine Hébert , Nathan G. Earley, John D. Reynolds, Diane Srivastava, Brian M. Starzomski, Michelle Tseng, Guillaume Larocque, James Pagé, Ciara Raudsepp-Hearne, Peter Soroye, Sandra Emry, David AGA Hunt, Pierre Rogy, Christophe Brabant, Stephen Deedes-Vincke, M. Camila Diaz-Corzo, Lukas Eckert, Kristyn Eckhardt, Sue Elwell, Nicole J. Kester, Joshua Sean Lee , Shirley Morrison, Eniola Olu-Ayorinde, Lindsay L. Trottier, Lukas van Riel, Sarfaroz Yunusov, Isaac Eckert, Janaína de Andrade Serrano, Noah Wightman, Maho Horikawa, Ryan Hull, Leeya Nagpal, André-Philipp Drapeau Picard, Étienne Lacroix-Carignan, Derek Duplessis, Étienne Léveillé-Bourret, Marc-Antoine Poulin, Anthony B. Zerafa, Laura J. Pollock

To resolve persistent biases in conservation assessments and forecasting, we urgently need more systematic collection of biodiversity data. Citizen (or, community) science, despite its reputation for unstructured data, offers a particularly promising path forward, mobilizing participation at scales and speeds unmatched by traditional monitoring. Here, we introduce Blitz the Gap, a pan-Canadian initiative to guide citizen science with sampling ‘challenges’, bioblitzes and paid initiatives using iNaturalist. One year of semi-guided sampling helped to gain 540 species newly recorded on iNaturalist Canada, almost 50,000 km2 of added spatial coverage, better representation of northern climates, and new evidence to help identify Key Biodiversity Areas. These results demonstrate the potential for guided citizen science, especially for taxonomic discovery, range-filling, and early alerts for species on the move. Our experience highlights the need for more tailored guidance and gamification, further development of adaptive sampling methods, and funding for bioblitzes and training of future taxonomists and naturalists. As countries work towards global conservation targets for 2030 and 2050, citizen science should be one of the core pillars of any large-scale monitoring network, contributing unparalleled taxonomic depth and engagement.