Coral cover is a measure of the proportion of reef surface covered by live stony coral instead of sponges,algae, or other organisms. Stony, reef-building corals are the main contributors to a reef’s three-dimensional framework—the structure that provides critical habitat for many organisms.
Coral cover is a good measure of general reef health. Every reef has its own “personality,” but, in general, a ” healthy” MAR reef typically has:
- Relatively high % coral cover
- Moderate % crustose coralline, calcareous, and short turf algae
- Low % fleshy macroalgae
A rapid shift away from coral domination can be a sign of ecosystem stress.
We recommend that benthic cover, including coral cover, continue to be routinely monitored.Coral cover is one of the most common measurements in reef monitoring programs. Well-defined protocols have been published by AGRRA, MBRS,and others.4 We recommend that a concerted effort be made to synthesize historical data, especially pre-1960
A good sign of Benchmark reef recovery would be a MAR-wide average of 15-20% live coral cover.
- In the 1980s, coral cover declined significantly in the wake of acroporid (staghorn and elkhorn coral) losses and the Diadema (F12) die-off.5
- In the 1990s,two bleaching events (1995 and 1998; F7, D14) and several hurricanes (most notably Hurricane Mitch in 1998) caused additional punctuated declines.6
- Regional 1999-2000 AGRRA surveys found an average of 14% live coral cover. Average coral cover was slightly higher on fore reefs than on reef crests.7