Corals of the genus Porites are a locally abundant component of the epibiont community on mangrove prop roots at Calabash Caye, Turneffe Atoll, Belize

Mangrove prop roots support diverse epibiont communities, but they are generally regarded as inhospitable for corals. However, recent reports have documented corals thriving on mangrove roots in the U.S. Virgin Islands and Cuba, and it has been proposed that mangroves may provide a refuge from environmental conditions that trigger coral mortality on nearby reefs. It also raises interesting questions about the potential evolutionary significance of coral populations in mangrove forest. We investigated diverse mangrove habitats for the presence of corals at Calabash Caye, Belize, part of a recently designated marine reserve on Turneffe Atoll. Here we present data on the distribution, size and morphology of 127 colonies of branching Porites found in a survey of 1858 meters of mangrove prop roots fringing three qualitatively distinct bodies of water: a high-flow channel, a moderate-flow creek, and a low-flow mangrove pond. The distribution of Porites was highly clumped, with 108 colonies occurring in a 178-meter stretch of shoreline along the high flow channel. Colony morphology varied widely, from bushy colonies with more than 40 branch tips per 1000 cm³ of ecological volume, to spindly colonies with fewer than 10 branch tips per 1000 cm³, to new recruits that have not yet developed distinct branches. Comparisons of the same coral-bearing roots in 2013 and 2014 revealed that colonies can experience substantial growth in a year’s time. We also document a much more diverse coral fauna living in the mangroves at Crooked Creek, a high flow environment on the western edge of Turneffe Atoll. The data described here contribute to an emerging picture of mangroves as potentially important habitat for corals, while suggesting that different types of mangrove habitat vary in their suitability for different species of coral. Future studies are needed to identify the critical environmental features of mangrove habitats that support coral, to further characterize those corals that can utilize mangrove habitat, and to investigate potential connectivity between coral populations in mangroves and nearby reef habitats.