ASSESSING DIVERSITY AND PHYTOREMEDIATION POTENTIAL OF SEAGRASS IN TROPICAL REGION
Seagrass ecosystem is one of the most important resources in the coastal areas. Seagrasses support and provide habitats for many coastal organisms in tropical region. Seagrasses are specialized marine flowering plants that have adapted to the nearshore environment with heterogeneous landscape structures of shallow-water estuarine/marine ecosystems. This unique feature of seagrass has rendered it to have high phytoremediation potential. Phytoremediation is a cost-effective plant-based approach and environmentally friendly solution for heavy-metal contaminated sites. The main objectives of the study were to determine the current status and diversity of seagrass ecosystem and to assess the phytoremediation potential of seagrass for lead and chromium in tropical region. Diversity of seagrass species in the study area was relatively low and only a few number of species and only a few number of individual per species were present due to environmental degradation caused by natural and human activities. Using the Shannon Diversity Index, the seagrass beds at Candelaria site had a diversity mean value of 1.6 while the Masinloc site had an average diversity value of 1.1, which indicate that both sites have very low diversity of seagrasses. Phytoremendiation efficacy of seagrass varied among coastal substrates and seagrass beds. While lead and chromium were not present in water, chromium was present in the sediment of the seagrass ecosystem in Candelaria and Masinloc, Zambales and lead was present only in the sediment of Masinloc, Zambales. Cymodocea rotundata was found to be a good phytoremediator for lead due to high amount of lead absorbed in both seagrass ecosystems. Chromium was not absorbed by C. rotundata, T. hemprichii and S. isoetifolium in both seagrass ecosystems.