Statistical Analyses
All analyses were conducted using R [22]. We used mixed linear effects models (lme4 [23]) to analyse the coral and fish abundance, using survey year as fixed and location as a random effect. Butterflyfish community analyses were conducted using a PERMANOVA from the Vegan package [24], with 999 permutations using sequential sums of squares. Location was fitted as the first term in the model, so that that any variation among location is accounted for before testing the effect of years (full model: abundance ~ location + year).  Pairwise analyses between years were conducted with the PairwiseAdonis package [25].