Annielyn Deocampo-Tampus, DiSDS Professor, Department of Marine Science at Mindanao State University Iligan Institute of Technology                                                      Expertise: marine science, macroinvertebrates, microplastics in sediments, and marine resource management in Iligan Bay and adjacent municipalities.

Assessment of Blue Carbon Stocks and Fish Communities of Natural and Reforested Mangrove Forests in Iligan City and Bacolod, Lanao del Norte, Philippines:                                    Mangrove ecosystems are vital coastal habitats that provide important ecological services, including carbon sequestration and biodiversity support. This study assessed and compared the above-ground blue carbon stocks and associated fish communities of natural and reforested mangrove forests in Bacolod and Iligan City, Lanao del Norte, Philippines. Mangrove vegetation was surveyed using plot-based sampling to determine species composition, stand structure, above-ground biomass (AGB), and carbon stocks through allometric equations. Environmental DNA (eDNA) metabarcoding was utilized to characterize fish communities associated with the mangrove habitats. Four mangrove species were identified: Rhizophora mucronata, Rhizophora stylosa, Sonneratia alba, and Avicennia marina. Both sites exhibited low species diversity, with Shannon-Wiener diversity indices of 0.70 for the natural stand and 0.49 for the reforested stand. The natural mangrove forest showed greater structural complexity, larger tree diameters, and higher biomass than the reforested forests. Total above-ground biomass reached 822.54 Mg ha⁻¹ in the natural stand and 451.21 Mg ha⁻¹ in the reforested stand. Carbon stock estimates were likewise higher in the natural stand, with Sonneratia alba contributing the largest share of biomass and carbon storage. eDNA metabarcoding generated 541,579 filtered reads and detected 118 molecular operational taxonomic units (MOTUs), representing over 100 fish species from 44 families. Fish assemblages were more diverse in the natural mangrove forest than in the reforested stands, reflecting the influence of habitat complexity and vegetation diversity. The findings emphasize the importance of conserving natural mangrove forests while supporting restoration efforts and demonstrate the effectiveness of eDNA metabarcoding as a non-invasive approach for biodiversity monitoring and management.