The distribution and community structure of mid-Holocene, tropical benthic foraminiferal assemblages were analyzed for their correspondence to marine habitats and invertebrate facies. Benthic foraminifera are useful for paleoenvironmental reconstructions because the modern ecology of many species found as Quaternary fossils is known. Samples were collected from ~30,000 m2 of an excavated Acropora cervicornis-dominated mid-Holocene reef with an age of ~6 kyr on Isla Colón, Bocas del Toro, Caribbean Panama. Bulk sediment samples were collected from a maximum depth of ~7 m below modern mean sea level and classified into five biofacies based on field observations of primarily corals and mollusks: 1) A. cervicornis-dominated reef, 2) molluscan mud, 3) Porites/Agaricia, 4) fringing reef and 5) seagrass. Sediment carbon and grain size analyses along with the relative abundance of species per sample and Fisher's alpha diversity index were used to compare sample similarity and environmental variables to identify any relationships. Most samples contained high total inorganic carbon content and poorly sorted, medium-coarse sediments. Principle component analysis of sediment grain size and carbon values did not show a clear association between samples, habitat type or location of trenches in respect to one another. Acropora cervicornis and other reefal samples contained the greatest foraminiferal diversity and were indicative of normal-marine conditions, while molluscan mud samples with high total organic carbon content were least diverse resulting from dominant Ammonia and Elphidium taxa. Seagrass samples were differentiated from molluscan mud samples and had similar diversities and species assemblages to Porites/Agaricia samples. Based on the distribution of foraminiferal species across this mid-Holocene coral reef, we conclude that it was a patch reef similar to those of modern Bocas del Toro. Results from this study can be used for comparison to modern foraminiferal studies to investigate whether the modern habitats of BDT are significantly different from the pristine reefs of the mid-Holocene.
