Short-term sediment plume event in the coral reef area of a small island captured by the Planet Dove satellite constellation

Abstract

ABSTRACT Sediment discharge from tropical and subtropical islands significantly influence the habitat and survival of the surrounding corals. However, severe observational difficulties have hitherto prevented all the efforts to capture these events and estimate their corresponding effects. Herein, we first report the details about a short but significant sediment plume event in coral reef areas of Kumejima Island, a small island near Okinawa, Japan, based on remote sensing data of high spatio-temporal resolution obtained by the Planet Dove satellite constellation. We developed a model for estimating the concentration of suspended solids (SS) based on laboratory spectral measurements and applied it to the red band of optical satellite data to quantify and map SS concentrations of the plume event. During this event, the level of SS concentrations near the coast were high that can cause acute negative impacts on corals. Our study emphasizes the importance of capturing such short-term events and providing essential information as reference basis for formulating countermeasures to control soil discharges and propose spatial strategies on land aimed at the conservation of coral reef ecosystems.