Fine sediment trapping in two mangrove-fringed estuaries exposed to contrasting land-use intensity, Palau, Micronesia

A comparative study was undertaken of the fate of fine sediment in the Ngerikiil and Ngerdorch mangrovefringed\ud estuaries in Babeldaob Island, Palau, Micronesia, in 2002. The mangroves comprised 3.8% of each catchment area, and in both systems, they trapped about 30% of the riverine sediment. Mangroves are important buffers protecting fringing coral reefs from excessive sedimentation. The sediment yield was significantly higher in the Ngerikiil River catchment (150 tons km2 yr1) that has been extensively cleared and farmed, than in Ngerdorch River catchment (1.9 tons km2 yr1) that was still relatively pristine during the study period