UTILIZING CORAL REEF SUB-FOSSIL ASSEMBLAGES TO ASSESS STABILITY AND CHANGE IN BELIZEAN REEF COMMUNITIES OVER THE PAST 800 YEARS PART B

Since monitoring of coral reefs began in the 1970s, the health of Caribbean coral reef ecosystems has declined substantially due to a suite of anthropogenic stressors. The history of Caribbean coral reef health and environmental changes before monitoring began is not as well understood, although recent work on cores from Panamanian reefs suggest that decline may have begun long before the mid 20^th century. A clearer picture of millennial-scale changes in reef ecosystems is necessary for understanding human impact and setting baselines for conservation. Subfossil assemblages from reef sediment cores can be used to survey historic changes in faunal composition and infer environmental changes. We studied a 3.3-meter-deep sediment core from the central lagoon of the Belize Barrier Reef dated to ~1200 CE at its base. We observed a moderate decrease in the relative abundance of epifaunal bivalves in comparison to infaunal bivalves starting in the late 1700s, implying a loss of hard coral substrate. Similarly timed changes have been reported in Panama, though they were not observed in a nearby Belizean core. A much more dramatic decrease in epifaunal bivalve relative abundance occurred at the top of the core, dated to the 1970s, which is consistent with other localities in Belize. These findings lend further credence to the idea that anthropogenic Caribbean reef degradation extends further back in time than previously thought and can be linked to resource-use changes following European colonization of the Americas.