Monitoring of marine debris in the Sea of Japan using multi-spectral satellite images

The flow of marine debris in the ocean causes extensive damage to coastal environments. In addition to local rivers, a large proportion of the marine debris that washes up along the coastline of the Sea of Japan originates in neighboring countries. It is considered important to understand the flow of marine debris in the Sea of Japan for environmental research purposes and for international relations. This study describes the results of monitoring marine debris flows using multi-spectral satellite images. The small size of most marine debris means that it cannot be confirmed directly, even when using high spatial resolution satellite imagery. Thus, to extract candidate pixels containing possible marine debris, pixels with spectra that differ from those of the surrounding ocean and the wave crests were identified. As a first step towards monitoring marine debris, a method for identifying marine debris floating on the Sea of Japan has been proposed using two-dimensional scatter diagrams of satellite spectral bands.