Indicator/Keystone Species

Coral Reefs:

Corals are affected by water turbulence, light penetration, salinity (needs a minimum), cloud cover, tidal, emersion, and tectonic events, so monitoring these things is a good way to determine how healthy coral is. The shape of coral in presence of corallivores or under physical stress is that terminal branches are clavate or flaring, so examining the shapes of coral is effective. Sediment samples, since Eucidaris (which prey on coral) generate carbonate sediments from coral, will also be a possible indicator.

Several papers have suggested using butterflyfish (genus Chaetodon) as an indicator species within coral reefs. This is a feasible option in some areas. Specifically, the species Chaetodon humeralis lives in the waters around Bartolome and Santiago Islands (see Fishes page), so population counts of this fish around those islands would work.

Terrestrial Keystone Species:
- Mycorrhizal fungi

-nitrogen-fixing bacteria

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