Environ Monit Assess (2010) 171:345–351 DOI 10.1007/s10661-009-1282-1 Can juvenile corals be surveyed effectively using digital photography?: implications for rapid assessment techniques Scott C. Burgess · Kate Osborne · Bianca Sfiligoj · Hugh Sweatman Received: 1 April 2009 / Accepted: 3 December 2009 / Published online: 15 December 2009 © Springer Science + Business Media B.V. 2009 Abstract The widespread decline of coral reefs requires integrated management measures across whole regions. Knowledge of demographic processes of reef organisms is important for informed management, yet current techniques for assessing such processes are time consuming, making it impractical to gather relevant informa- tion over large scales. We tested the usefulness of digital still photography as a rapid assessment technique to estimate coral recruitment—an im- portant process in coral reef recovery. Estimates of the density and diversity of juvenile hard corals from digital images were compared with direct visual estimates from the same plots made in the field. Multiple plots were sampled on four reefs from a range of locations on Australia’s Great S. C. Burgess · K. Osborne · H. Sweatman Australian Institute of Marine Science, PMB No.3, Townsville MC, Townsville, Queensland 4810, Australia B. Sfiligoj Life & Environmental Sciences, Deakin University, Princes Highway, Warrnambool, Victoria 3280, Australia Present Address: S. C. Burgess (B ) School of Biological Sciences, The University of Queensland, Brisbane 4072, Australia e-mail: scott.burgess@uq.edu.au Barrier Reef. On average, estimates of juvenile densities from photographic images were lower, in both absolute and relative terms, than that estimated from images. This was the case whether colonies <20 mm or <50 mm in diameter were considered. Overall differences between methods were generally greater at reefs where recruitment was higher, though proportional differences (density from images/density from direct visual census) still varied among reefs. Although the ranking of taxa, in terms of their densities, from the two methods were similar, the density of common genera was generally underestimated in images, and the occurrence of ‘unknown’ taxa was higher. We conclude that photographic images do not constitute a reliable rapid assessment method for estimating the spatial patterns in the density or diversity of juvenile hard corals. Keywords Coral recruitment · Digital photography · Method comparison · Monitoring methods · Rapid assessment methods Introduction The increasing pressure on coral reef health worldwide calls for the management of coral reefs across large spatial scales (Nyström et al. 2000; Wilkinson 2004; Sweatman et al. 2008). Monitor- ing data on the status and trends of hard corals