Nutrients in mangrove sediment as a growth factor in coastal rehabilitation areas in East Halmahera, North Maluku, Indonesia

Akbar, Nebuchadnezzar; Marus, Ikbal; Ismail, Fildaut; Muchdar, Fatma; Suryani, Suryani; Baksir, Abdurrachman; Ramili, Yunita; Paembonan, Rustam E; Najamuddin, Najamuddin -; Supyan, Supyan; Widhi, Raut Nugrahening; Siolimbona, Abdul Ajiz

doi:10.21608/ejabf.2025.415886.6442

Nutrients in mangrove sediment as a growth factor in coastal rehabilitation areas in East Halmahera, North Maluku, Indonesia

Document Type : Original Article

Authors

¹ Marine Science Departement, Faculty of Fisheries and Marine Science, Khairun University. Gambesi Campus, Ternate 97716, North Maluku, Indonesia

² Marine Science Departement, Faculty of Fisheries and Marine Science, Khairun University. Gambesi Campus, Ternate 97716, North Maluku, Indonesia.

³ Departement of Marine Science Faculty of Fisheries and Marine Science

⁴ Study Program of Aquatic Resource Management, Faculty of Fisheries and Marine Science, Khairun University, Jl. Jusuf Abdurrahman, Gambesi, Ternate 97719

⁵ Aquatic Resource Management Departement, Faculty of Fisheries and Marine Science, Khairun University. Gambesi Campus, Ternate 97716, North Maluku, Indonesia.

10.21608/ejabf.2025.415886.6442

Abstract

The implementation of coastal ecosystem rehabilitation through mangrove replanting has been carried out in East Halmahera, North Maluku, Indonesia. Based on evaluation and monitoring conducted every six months after replanting, mangrove growth has been relatively slow, with an average monthly stem growth of 0.99cm and a leaf growth rate of only 1–2 leaves per month. Thus, this study aimed to analyze sediment nutrient content as a determining factor for mangrove growth in rehabilitation areas of East Halmahera. Field data collection was conducted in June 2024 at the mangrove rehabilitation site in Buli, followed by laboratory analysis of sediment nutrient content. Results from phosphate and nitrate measurements in mangrove vegetation on the Moronopo side indicated that phosphate content was the highest in research area B (0.39 mg/100 g), compared to area A (0.0441mg/ 100g). The highest nitrate content was recorded at location B2 (0.37%), followed by B3 (0.31%), while the lowest nitrate concentration was observed at location B4 (0.10%). Overall, the analysis shows that nitrate levels at the study site are relatively low. Both phosphate and nitrate concentrations in the sediment were low, which is likely due to limited organic matter inputs in the rehabilitation area. This condition is exacerbated by the high sludge content of the site, which may further constrain nutrient availability and hinder mangrove growth.

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