Abstrak
Foraminifera and nannoplankton assemblages were studied in fifteen surface sediment samples from Madura Strait. Thirty-seven benthic and 16 plankton foraminifera taxa as well as 22 nannoplankton taxa were identified. Plankton foraminifera do not occur in water depths of less than 20 meters. However, benthic foraminifera assemblages occur and are dominated by Florilus angulatus. Nannoplakton assemblages are very rare, being about 1% of the total sediment in these relatively shallow depths. These nannoplankton assemblages are made up of single species, Gephyrocapsa oceanica. In the neritic zone, which is indicated by accumulation of very fine-grained sediment, plankton and benthic foraminifera assemblages are increasingly more abundant and have higher diversity. Nannoplankton assemblages are dominated by Gephyrocapsa oceanica, though Emiliania huxleyi and Florisphaera sp. are common components in the assemblages in the study area is closely related to bathymetry. The abundance and diversity index of assemblages increase with increasing water depth.