Composition and Spatial Distribution of Benthic Foraminifera from Two Tropical Estuaries (7° S, Brazil)

This study investigates the composition and spatial distribution of benthic foraminiferal assemblages in the estuaries of the Mamanguape and Paraíba rivers in Northeast Brazil. Samples were collected from different sectors along both estuaries and analyzed for foraminiferal density, diversity, and species composition in relation to abiotic factors like salinity, temperature, pH, and sediment grain size. Results show that calcareous foraminifera dominate both estuaries, likely influenced by stable pH and salinity gradients. Additionally, the sediment composition of both estuaries varies from typical tropical estuarine patterns, with the presence of coarse and medium sands suggesting significant environmental dynamics. Statistical analyses confirm that foraminiferal assemblages reflect spatial environmental variations within and between the estuaries, underscoring the potential of foraminifera as bioindicators in coastal ecosystem assessments.