Resilience in carbonate production despite three coral bleaching events in 5 years on an inshore patch reef in the Florida Keys

The persistence of coral reef frameworks requires that calcium carbonate (CaCO3) production by corals and other calcifiers outpaces CaCO3 loss via physical, chemical, and biological erosion. Coral bleaching causes declines in CaCO3 production, but this varies with bleaching severity and the species impacted. We conducted census-based CaCO3 budget surveys using the established ReefBudget approach at Cheeca Rocks, an inshore patch reef in the Florida Keys, annually from 2012 to 2016. This site experienced warm-water bleaching in 2011, 2014, and 2015. In 2017, we obtained cores of the dominant calcifying coral at this site, Orbicella faveolata, to understand how calcification rates were impacted by bleaching and how they affected the reef-wide CaCO3 budget. Bleaching depressed O. faveolata growth and the decline of this one species led to an overestimation of mean (± std. error) reef-wide CaCO3 production by + 0.68 (± 0.167) to + 1.11 (± 0.236) kg m−2 year−1 when using the static ReefBudget coral growth inputs. During non-bleaching years, the ReefBudget inputs slightly underestimated gross production by − 0.10 (± 0.022) to − 0.43 (± 0.100) kg m−2 year−1. Carbonate production declined after the first year of back-to-back bleaching in 2014, but then increased after 2015 to values greater than the initial surveys in 2012. Cheeca Rocks is an outlier in the Caribbean and Florida Keys in terms of coral cover, carbonate production, and abundance of O. faveolata, which is threatened under the Endangered Species Act. Given the resilience of this site to repeated bleaching events, it may deserve special management attention.