Can juvenile corals be surveyed effectively using digital photography?: implications for rapid assessment techniques
Scott C Burgess1, Kate Osborne, Bianca Sfiligoj
1Australian Institute of Marine Science, PMB No.3, Townsville MC, Townsville, Queensland, 4810, Australia. scott.burgess@uq.edu.au
Environmental Monitoring and Assessment
|December 17, 2009
Summary
Digital photography is not a reliable method for assessing coral recruitment. Direct visual surveys are more accurate for estimating juvenile coral density and diversity on reefs.
Area of Science:
- Marine Biology
- Ecology
- Conservation Science
Background:
- Coral reef decline necessitates effective management strategies.
- Accurate demographic data for reef organisms are crucial for conservation.
- Current assessment methods for coral recruitment are labor-intensive and impractical for large-scale application.
Purpose of the Study:
- To evaluate digital still photography as a rapid assessment technique for estimating coral recruitment.
- To compare coral recruitment estimates from digital images with direct visual assessments.
Main Methods:
- Digital still photography was used to capture images of juvenile hard corals.
- Image-based density and diversity estimates were compared with direct visual estimates from the same plots.
- Sampling was conducted on four reefs within Australia's Great Barrier Reef.
Main Results:
- Photographic estimates of juvenile coral densities were consistently lower than direct visual estimates.
- Differences were more pronounced at reefs with higher recruitment rates.
- While taxa rankings were similar, common genera were underestimated, and 'unknown' taxa increased in image analysis.
Conclusions:
- Digital photography is not a reliable rapid assessment method for spatial patterns of juvenile hard coral density or diversity.
- Direct visual census remains a more accurate method for assessing coral recruitment.
