Mean overall coral disease prevalence was approximately 3-fold
greater at sites with high visitation (mean ± SE = 14.5% ± 4.0; 727
cases of disease) compared to low use sites (5.2% ± 1.3; 197 cases
of disease; Table 1). At low use sites, disease prevalence ranged
between 1.2% and 8.5% (median = 5.6%), whereas it ranged
between 6.9% and 29.9% (median = 11.4%) at high use sites. Both
the maximum prevalence and maximum number of cases of each
of the four diseases were recorded at high use sites (Table 1). No
cases of brown band disease, a common ciliate disease in the
Indo-Pacific (Willis et al., 2004), were recorded during these surveys.
The two most prevalent diseases, skeletal eroding band
(SEB) and white syndromes (WS), were 2-fold and 4-fold greater,
respectively, at high use sites than at low use sites (Table 1 and
Fig. 3a). Mean black band disease (BBD) prevalence was low at
all sites, however it was 9-times greater at high use sites than
low use sites, although it did not differ significantly between use
levels (Table 1 and Fig. 3a). There was no difference in the mean
prevalence of growth anomalies between the two use levels
(Table 1 and Fig. 3a).