Assessing the Relationship between Coastal Reclamation and Seagrass Ecosystems in Coron, Palawan using Multitemporal Remote Sensing, Shoreline Change Analysis, and Turbidity Mapping

Abstract. Coastal reclamation can be a threat to benthic habitats, which include seagrass meadows. However, long-term data to assess seagrass response to reclamation are limited due to time and logistics challenges. Hence, this study aims to assess the environmental impact of the Coron reclamation project in Palawan on the seagrass meadows (2005-2023) using multitemporal remote sensing, shoreline change analysis, and turbidity mapping. The results show that seagrass cover generally declined with a loss of 289,816 square meters (28.98 hectares) near the reclamation area. On the other hand, turbidity levels were found to increase near the reclamation area, and the shoreline generally experienced accretion with an average rate and distance of 2.19 meters per year and 39.36 meters, respectively. Time-series analysis revealed that shoreline expansion, which is due to reclamation, and seagrass area have a negative correlation (r=- 0.58, p=-0.52). Similarly, turbidity has an inverse relationship with seagrass cover (r=-0.601, p=-0.684). Although the reclaimed shoreline covers only 2.7 kilometers (9.87%) of the total analyzed shoreline, it resulted in a seagrass loss of 28.98 hectares, equivalent to 67% of the 43-hectare reclaimed area. These findings emphasize the need for stricter environmental impact monitoring, as well as seagrass conservation policies to safeguard marine habitats in Coron and similar coastal communities.