||Seagrass can provide key ecological services to neighboring habitats in tropical and
temperate regions, but evidence shows that they are experiencing significant widespread
decline. Coastal human population pressures have played a most important role. This
study focused on the damage of boating, propeller scars, which may lead to direct
loss of seagrass and increased susceptibility of seagrass beds to damage from hurricanes.
The goal of this study is to explore the methods for seagrass mapping based on remote
sensing imagery, and to evaluate the impact of human activities on seagrass beds.
A transect at Core Banks in Beaufort, NC was selected as the study area. Data sources
for this study includes unoccupied aircraft system (UAS) surveyed color mosaics (2.5-
to 3-cm pixel size), and high resolution multispectral satellite imagery (RapidEye.
5-m pixel resolution). Based on the analysis, this study provides a successful application
of Object-Based Classification in classifying coastal submerged areas in UAS images;
human activities have been proven to have lasting effects on seagrass habitat, since
seagrass in scar-affected regions has a greater rate of both growth and decline, and
scars in areas with higher density of seagrass are more likely to recover. In addition,
this study also shows that automated seagrass mapping is feasible using high-resolution
satellite imagery and a newly developed index, ReGNDVI (Red Edge-Green NDVI), which
has the potential for large-area seagrass mapping. The findings of this study provided
useful suggestions on conservation of coastal areas.