OCEANOGRAPHIC DYNAMICS AND THEIR EFFECTS ON SEDIMENTATION RATES IN THE MESJID RIVER ESTUARY, DUMAI

Ilham Ilahi (Department of Marine Science, Faculty of Fisheries and Marine, Universitas Riau)
Mubarak Mubarak (Department of Marine Science, Faculty of Fisheries and Marine, Universitas Riau, Pekanbaru 28293 Indonesia)
Nabila Afifah Azuga (Department of Marine Science, Faculty of Fisheries and Marine, Universitas Riau)
Gita Purnama Sari (Department of Marine Science, Faculty of Fisheries and Marine, Universitas Riau, Pekanbaru 28293 Indonesia)
Vina Rahmadhani (Department of Marine Science, Faculty of Fisheries and Marine, Universitas Riau, Pekanbaru 28293 Indonesia)
Benny Heltonika (Department of Aquaculture, Faculty of Fisheries and Marine Sciences, UNRI)

Asian Journal of Aquatic Sciences
Vol. 9 No. 2 (2026): August

This study analyzes the oceanographic dynamics (bathymetry, tides, and shoreline changes) and their impact on sedimentation rates in the Mesjid River estuary, Dumai, Indonesia, which faces the Malacca Strait. The research was conducted from July to September 2025 at two stations using sediment traps, bathymetric surveys, and NDVI analysis for mangrove cover. The results show an estuarine depth ranging from 2.34, with significant shallowing at the river mouth. The tidal pattern is classified as mixed, with a semidiurnal predominance (Formzahl number = 0.43). Shoreline change analysis indicates that abrasion from ship-generated waves and mangrove degradation dominate. The average sedimentation rate reached 7.22 cm/year, with the highest accumulation observed at the estuary mouth due to current deceleration and sediment trapping by mangrove roots. Oceanographic dynamics and anthropogenic pressures amplify sedimentation in this tropical estuary.