Ecological impacts of unsustainable sand mining: Urgent lessons learned from a critically endangered freshwater cetacean

Sand dredgers and sand barges were identified using Landsat 5 Thematic Mapper (TM), Landsat 7 Enhanced Thematic Mapper-plus (ETM+), and Landsat 8 Operational Land Imager (OLI) orthorectified top-of-atmosphere (TOA) reflectance images. The identification process was performed on Google Earth Engine. Locations and acquired dates of the identified sand dredgers/barges were extracted and transferred to a geographical information system for further analysis (GIS, ArcMap 10.3). The porpoise distribution data was compiled from nine lake-wide surveys conducted from 2006 to 2019. Sighting records with geographic information were used for analysis in this study.