Benthic foraminifera in surface sediments of the Gulf of Guinea

Recent benthic foraminifera from the Gulf of Guinea (West Africa) were investigated as part of the NOSOFO project (North South Foraminiferal Transect), which concerns the latitudinal distribution of foraminifera in the eastern Atlantic Ocean. The Gulf of Guinea is particularly interesting because of the local confluence of fluvial waters with both coastal and equatorial upwelling systems. The distribution of the samples along 11 transects from Guinea to Gabun enables the determination of the effect of the spatial variation in the input of organic material to the benthic ecosystem. Thus, the benthic foraminiferal fauna is of interest for its modern ecological response and for its potential use as an indicator of the shifting, waxing and waning, and interacting of these systems through time.
The material consists of 53 surface sediment grab samples from water depths of 27 to 560 m taken during the METEOR cruise 6-5, Dakar - Libreville in January and February, 1988. Bioceonoses from of the uppermost centimeter of the sediment were investigated, using the 63 - 250 µm grain fraction; thanatocoenoses were analyzed from 22 of these samples. In addition, biocoenoses from 10 sediment cores which represent the first 1 - 6 cm underlying the grab samples were analyzed. Living specimens were stained with Rose Bengal and seperated from the unstained tests.