Abstract
The mass die-off of Caribbean corals has transformed many of this
region’s reefs to macroalgal-dominated habitats since systematic
monitoring began in the 1970s. Although attributed to a combination of
local and global human stressors, the lack of long-term data on
Caribbean reef coral communities has prevented a clear understanding of
the causes and consequences of coral declines. We integrated
paleoecological, historical, and modern survey data to track the
prevalence of major coral species and life history groups throughout the
Caribbean from the pre-human period to present. The regional loss of
Acropora corals beginning by the 1960s from local human
disturbances resulted in increases in the prevalence of formerly
subdominant stress-tolerant and weedy scleractinian corals and the
competitive hydrozoan Millepora beginning in the 1970s and 1980s.
These transformations have resulted in the homogenization of coral
communities within individual countries. However, increases in
stress-tolerant and weedy corals have slowed or reversed since the 1980s
and 1990s in tandem with intensified coral bleaching. These patterns
reveal the long history of increasingly stressful environmental
conditions on Caribbean reefs that began with widespread local human
disturbances and have recently culminated in the combined effects of
local and global change.