Seagrass Distribution Area Computations At Tidung Island, Seribu Islands Regency Jakarta Province, Indonesia

Abstract

Seagrass ecosystem posses important ecological aspects like primary production, biota habitat, sedimentation catching area, nutrient recycling, and CO2 absorptions. Seagrass plantation destructions may due to antropogenic activity causing seawater decreasing quality and also coastal environmental. Development activity at coastal region like soil hoarding, landfill and coastal transportation also posses huge contribution onto seagrass ecosystem damaging. Seagrass ecosystem monitoring could be conducted utilising remote sensing technology. The study is to compute and to map the distribution of seagrass areas exists on Tidung Island, and evaluate the changes to some extent. Field data collections and satellite image processing were conducted. The supervised classification performed on Sentinel 2A satellite images year 2017 and 2019 respectively. The image classification results indicated four classes, namely nonseagrass, solid seagrass, medium seagrass and rarely seagrass. In 2017 seagrass areas obtained 43.47 hectares (0.435 km2) and non seagrass of 217.93 hectares (2,178 km2), but in 2019 the seagrass areas of 58.67 hectares (0.587 km2) and non-seagrass of 202.73 hectares (2,027 km2). There indicates a change in the seagrass into non-seagrass areas around 39.89 hectares (0.399 km2) and non-seagrass which became seagrass area of 24.69 hectares (0.247 km2). The accuracy value obtained was 74.90 %. However, it has been succesfully conducted computations on alteration seagrass areas and mapping spatially at Tidung Island, Indonesia.