Satellite monitoring of Green and Golden-tide in the Eastern Yellow Sea

Abstract

In the Yellow Sea, macroalgae bloom of Ulva (also called green tide) have been reported since 2008, and macroalgae bloom of Sargassum (also called golden tide) also observed since 2013. Remote sensing is considered to be a very effective method to monitor the distribution, areal extent and migration of floating macroalgae. However, although a number of studies used remote sensing to estimate their spatial distributions and temporal changes, most studies are focused in the western part of the Yellow Sea (YS), very little information is available in the eastern part. Furthermore, the long-term distribution and migration of floating golden tide is unknown. The aim of this study is to clarify the long-term distribution pattern of green and golden tide in the eastern YS. In addition, we want to analyze the drift characteristic of floating macroalgae using remote sensing data. MODIS, GOCI and Landsat images from 2008 to 2017 were used to demonstrate the long-term distribution of floating macroalgae. The hourly images from GOCI were used to demonstrate the drift characteristic of floating macroalgae. Massive green tide was found in the eastern YS for the first time in 2008, and the satellite image traced back shows that it originated from the western YS. Large mass of green-tide found continuously, and its largest scale of any green-tide has been found in 2011. Floating golden tide was found in the eastern YS since 2013, an