Comparison between complex and simple reef survey techniques using volunteers: is the effort justified

Reef Check and GCRMN survey techniques were compared between the same volunteer divers on the same reef after different periods of training. Greenforce volunteers with no prior reef surveying experience were firstly taught to dive and then trained in reef fauna and flora identification and surveying techniques. After training, volunteers performed surveys using both Reef Check and the more detailed GCRMN categories. Three weeks later, the volunteers resurveyed the same transect lines. In addition, transects were surveyed by the on-site science staff. Most Reef Check categories were identified and counted correctly at all levels of experience. Useful information could also be collected by volunteers using the more detailed GCRMN benthic codes and fish survey techniques. Reef fish were easily identified to family and most target species were identified correctly. Experienced surveyors (staff) recorded a few additional species, but there was no significant difference between the numbers of target species seen by the two groups after three weeks. In a trial comparison of line point and line intercept the two techniques gave similar results for bottom cover estimates even though Reef Check generally records far fewer sampling points per transect than the GCRMN technique. For data on benthic cover only, Reef Check techniques were deemed adequate, while the increased effort required for coral morphology may be justified for more detailed studies