Foraminiferal communities of a mid-Holocene reef: Isla Colón, Caribbean Panama

The distribution of mid-Holocene, tropical benthic foraminiferal assemblages, including species' proportions, diversity, dominance and wall type, were analyzed for their correspondence to marine habitats invertebrate facies. Benthic foraminifera are useful paleoenvironmental reconstructions because the modern ecology many species found as Quaternary fossils is known. Samples collected from trenches in ~30,000 m2 an excavated Acropora cervicornis-dominated, mid-Holocene reef with age ~6 kyr on Isla Colón (Colon island), bordering Almirante Bay Bocas del Toro, Caribbean Panama. Bulk sediment samples a maximum depth ~7 m below mean sea level classified field into five biofacies: 1) A. cervicornis-dominated reef, 2) molluscan mud, 3) Porites-Agaricia 4) mixed coral, 5) Lobatus-dominated seagrass. Sediment carbon grain size analyses, cluster analysis performed relative abundance per sample, Fisher's alpha diversity index used compare sample similarity environmental variables determine habitat relationships. Most contained high total inorganic poorly sorted, medium-coarse sediments. Principle component values did not show clear among samples, type or location trenches. Foraminiferal assemblages cervicornis other reefal (categories 1, 3 4, above) had greatest distinguish between three types, suggesting similar, normal conditions and/or mixing coral fragments. Molluscan mud organic content least diverse dominant Ammonia Elphidium taxa, though showed transition proximal corals. Seagrass differentiated similar diversities taxa known be temporary grazers living temporarily attached seagrass blades present relatively greater amounts these samples. Based across this we conclude that it was patch included high-organic facies those Bay. Results study can compared studies investigate whether BDT significantly different pristine reefs mid-Holocene.