Event preservation in lagoonal reef systems

Paleontological data suggest that coral populations in the Caribbean were consistently healthy for the past 2-3 k.y. Beginning in the 1980s, however, disease outbreaks, bleaching episodes, hurricanes, and other perturbations caused catastrophic coral mortality and regional turnover. An alternative hypothesis, based on historical sources, posits that coral populations were already declining more than a century ago. These hypotheses can be distinguished only if turnover events are reliably preserved in the Holocene record of coral reefs. Push-pores extracted from uncemented lagoonal reefs in Belize showed that a direct hit by Hurricane Iris in 2001 did not disrupt the signature of the recent turnover event, which entered the subfossil record essentially intact. Cores from lagoonal systems in several areas of the Caribbean do not support the hypothesis that corals declined before the 1980s.