Preliminary Study on The Bioaccumulation Potential of Sea Grass (H. Ovalis) For Mercury in Selected Coastal Barangay in Malita, Davao Occidental

Seagrass has a remarkable metal bioaccumulation capacity since it interacts directly with both the water column and the pore water through the leaves and roots as ionic uptake. Malita, Davao Occidental, has some extensive seagrass meadows that support populations of species like dugongs, turtles, and commercially and traditionally important fishes. This study aimed to determine the potential of seagrass in absorbing mercury. There were five species of seagrass observed in the study area (Halophila ovalis, Halodule uninervis, Halodule pinifolia, Halophila minor, and Halophila spinolusa). In New Argao, the highest mean percent cover (4.3%) and shoot density (519.2 shoots/m2) were obtained in H. ovalis, while the lowest mean percent cover (1.9%) and shoot density (197.87 shoots/m2) were recorded in Cullman. It was found that there were no significant differences in the density and abundance of H. ovalis between the sampling stations; however, there was a significant difference in the concentration of mercury between sampling stations. The mercury accumulation was observed to be high (41.9 ppb) and recorded from Tingolo, while in Culaman, the total quantity of mercury accumulated by H. ovalis was 21.5 ppb. There was a low positive correlation between mercury concentration and percent cover of H. ovalis, while a negative correlation (-0.518) was found between mercury concentration and shoot density. Because of the limited data available, conclusions about the relationships were not drawn. As to physicochemical parameters, the temperature, salinity, and pH recorded in all sampling stations were observed to be at their normal levels.