PRISTINE TO MODERN: A COMPARISON OF SHALLOW-WATER MODERN AND MID-HOLOCENE BENTHIC FORAMINIFERAL ASSEMBLAGES FROM COASTAL BOCAS DEL TORO, PANAMA
This study analyzes and compares the community structure of benthic foraminiferal assemblages from 38 sediment samples from BDT, including 20 shallow-water (~2 m avg.) modern samples and 18 from the mid-Holocene reef on Isla Colon. Unpublished 14C and U-Th ages from in situ A. palmata and A. cervicornis date the mid-Holocene subfossil samples to ~7.2-5.8k YBP. Initial cluster analysis results show clear differences between the mid-Holocene and modern samples, with few similarities. Seagrass and mangrove habitats are well-differentiated from reefal habitats, without respect to age. Mangrove samples show the least diversity, with near-even diversity between seagrass and reefal samples. Two proposed explanations for these results are 1) the modern samples were collected from coastal habitats in Almirante Bay which incorporate physiographic differences and coastal effects such as runoff and sediment input from nearby mountains, whereas the subfossil samples may reflect a normal, marine setting resulting from the isolation of Isla Colon from the mainland and 2) pollution and anthropogenic land-use changes have altered the modern coastal habitats. Ongoing analyses will help determine the cause for the observed differences between the ages, which has implications for the preservation and future restoration of coastal, tropical habitats.