Reef Check benthic survey error: a case study on the Great Barrier Reef

Minimization of observer-related error is important for coral reef monitoring programs because highly variable data will decrease the resolution by which environmental change can be detected. Thirty-eight Reef Check volunteers were tested on their benthic identification skills on the Great Barrier Reef and their performance improved after practice and feedback sessions. Participants who had prior experience with environmental volunteer programs initially scored consistently higher than those without this experience. A similar but less consistent trend was found for more experienced divers. This information can be used to assess how much training volunteers require to remove the effects of different experience attributes. All participants' scores moderated towards the end of the study. The misidentifications still made involved similar benthos for all participants. This may reflect a lack of previous familiarity with these benthos types. The Reef Check categories that participants found most difficult to identify included hard coral, soft coral, recently killed coral, sponge and other benthic organisms. The effectiveness of future training sessions could be increased if focus is placed on these problem areas of identification within these categories