In Study 1, 33 of the 38 investigated candidates showed significant
relationships with the water quality index, with their
direction of change (increase or decrease with decreasing WQ) inagreement with expectations based on their biological characteristics
(e.g., phototrophs vs. heterotrophs, etc.). In Study 2, 30 of the
38 investigated candidates showed the same direction of change
in response to higher turbidity, and 16 of these changes were significant,
with differences between geographical regions also often
being significant (Table 2 and Supplementary Table S1). Four candidate
bioindicators; skeletal density of Pocillopora, hard coral richness,
cover of Lobophyllia spp. and Pectinia spp., which all strongly
declined with increasing nutrients in Study 1, showed slightly positive
(but non-significant) slopes in Study 2. Because of the inconsistent
response in the two studies, these measures were not
considered as useful predictors of water quality