Spatial distribution and biogeographic significance of foraminiferal assemblages from Sao Tome and Principe, Gulf of Guinea, West Africa

Sao Tome and Principe islands are located closely to the equator within the tropical Atlantic Guinea Current Large Marine Ecosystem. The area is known for its rich biodiversity and vast hydrocarbon resources. The study of modern foraminifera in this region is new and we hereby present the first survey of benthic foraminifera from the shallow-water sites around both Sao Tome and Principe islands. We document the faunal composition, structure and habitat specificity of assemblages and compare the foraminiferal biotas to those found within the Gulf of Guinea, and other southern Africa coasts. Over 5700 benthic foraminifera belonging to 106 species including agglutinated, perforatehyaline and imperforate-porcellaneous types were recovered from 12 sample sites. Cluster, species richness and principal component analyses reveal habitat specific faunal assemblages characterized by distinct species composition and faunal indices. The coastal waters of Sao Tome and Principe were found to harbor more species of larger symbiont-bearing foraminifera (LBF) than ever recorded within the Gulf of Guinea region. The LBF recorded are numerically abundant, vital producers of carbonaceous sediments and are of particular biogeographic interest.