This research study comprehensively assessed seagrass characteristics using the transect quadrat method in Siargao Island, Surigao del Norte. Three 50 m transect lines and laid parallel, separated by a 25 m distance, and readings were taken using steel quadrats placed every 5 m along the transects. A total of 11 quadrats were laid in each transect, and five seagrass species were recorded: Cymodocea serrulata, Cymodocea rotundata, Thalassia hemprichii, Enhalus acoroides, and Halodule pinifolia.As displayed in Tables 2, 3, and 4, the outcomes showed the percentage of seagrass coverage in each quadrat and the corresponding seagrass species. The dominant species varied across the quadrats, highlighting the spatial variability in seagrass distribution. Transect 1 had the highest species richness, while Transect 3 exhibited the most dominance and evenness. The study also analyzed the substrate types in the site, including clay, silt, sand, gravel, and rock. The preference of seagrass species for coarse sand substrate was seen, while rocky substrates had minimal seagrass cover. Transect 3 predominantly featured a coarse sand substrate. The findings indicate that it is suggested to implement conservation and management measures to protect and preserve the seagrass ecosystems. Restoration efforts should be considered in areas with absent or poor seagrass coverage. The dominant seagrass species should receive special attention in conservation efforts. Long-term monitoring programs are crucial to track changes in seagrass coverage and species composition. Lastly, this research provides valuable insights into the seagrass characteristics and their interplay with substrate types in Siargao Island, Surigao del Norte. The findings contribute to the area’s understanding and conservation of seagrass ecosystems.














