Table 1.

Ecological indicator metrics and processes represented by each metric

Metric	Ecological change
Macroalgae, % cover	Greater macrolagal cover indicative of declining palatable algal production and calcification, declining herbivory, and possibly increased nutrient inputs
Ratio of macroalgae vs. hard coral.	Increased macroalgae relative to coral indicative of rates of algal production and declining calcification
Urchin predation index	The metric is indicative of top-down control of processes influenced by sea urchin predators (e.g., grazing). Lower index indicates lower rates of predation on invertebrates
Fish species richness	Reflects changes and loses in functional groups important for ecological redundancy and maintaining key processes
Sea urchin biomass	Increasing biomass suggests increased biological erosion rates of reef substratum, loss of coralline algae, and reef decay
Herbivorous fish as % of total fishable biomass	Reduced % suggests declining secondary production available to fisheries and reduced herbivory processes
Calcifying substrates % (hard coral and calcifying algae)	Lower % indicative of declining reef accretion and loss of reef complexity and habitat structure
Hard coral substrate, % cover	Lower % indicative of declining reef accretion, reef topographic complexity, benthic diversity, and abundance of coral-dependent species and associated processes, including larval recruitment

Based on coral reef ecological studies (20–25) (SI Methods).