Bioaccumulation Potential of Seagrass (Halophila sp.) for Mercury in the Selected Coastal Areas in Malita, Davao Occidental

Abstract

This research aims to determine the potential of seagrass Halophila sp.  in absorbing mercury in the selected coastal barangays in Malita, Davao Occidental. The study employs a quantitative type of research where strategies focus on quantifying the collection and analysis of data. The study was conducted from October 2020 to December 2021 in the three selected coastal Barangays in Malita, Davao Occidental namely Brgy.Culaman, Brgy. New Argao and Brgy. Tingolo. Transect line quadrat method was used to determine the percent cover and shoot density of seagrass. Using this method, the point of seagrass occurrence up to the outer limit where seagrasses disappears was determined. There were three (3) stations and three (3) transect lines were laid for each station with an interval of 50m. Five (5) quadrats were also laid in the seagrasses along the 50 meter transect line positioned perpendicular to the shoreline. The seagrasses were collected in each quadrat and the samples were transported to Davao Analytical Laboratories, Inc. for mercury analysis. The highest mean percent cover (10.27%), shoot density (128.91 shoots/m2) and Hg accumulation (572.9ppb) was recorded in Brgy. Tingolo, Malita, Davao Occidental while the lowest result was obtained by Brgy. Culaman, Malita, Davao Occidental. Halophila sp. has the capability to accumulate mercury content and exceeds the standard level of 20 ppb. There were no significant differences in the percent cover and Hg accumulation of seagrass Halophila sp. while significant difference is observed in the shoot density. However, there is a positive relationship (.664) between the shoot density and mercury concentration of Halophila sp.