Coastal Foraminiferal Assemblages along the southern coast of Oman: A biogeographic stepping stone for benthic foraminifera?

The shallow water ecosystems of Oman are subject to intense seasonal upwelling and unlike many other oligotrophic tropical areas, are impacted by strong, seasonal nutrient-rich eutrophic conditions. The environmental conditions provide a setting for presumably unique foraminiferal faunal assemblages, but despite intensive research on tropical foraminifera, detailed studies on coastal foraminifera have not yet been conducted. Situated at a key position between the high-diversity Coral Triangle and the tropical Red Sea/eastern African coast, the coastal waters of Oman act both as a biogeographic steppingstone but also as a nutrient-rich and cold-water barrier for benthic foraminifera migrating from the east to west. Upwelling zones have a deep impact on coastal areas, displace oligotrophic water masses and influence the settlement of highly diverse tropical coral reef and foraminiferal faunal communities. We have examined foraminiferal assemblages from extremely shallow but diverse habitats along the southern coast of Oman to document their composition, diversity and habitat preferences. To place the Oman assemblages in a biogeographic context and to assess the role of the Oman area as potential steppingstone, we compare the foraminiferal fauna to assemblages from the Maldives, the Chagos Islands, the Coral Triangle and the Red Sea/eastern African faunal province.