Analyzing Historical Hurricane Influences on Coastal Water Quality and their Impact to Marine Ecosystems

Several major and small-scale hurricanes have swept over the US Virgin Islands (USVI) dating back to 1989. Often originating near the Cabo Verde islands near western Africa, these major hurricanes travel westward towards the USVI, leaving destructive impacts upon landfall. Nearshore marine ecosystems in the USVI have adapted to hurricane forces, but as urban development alters native vegetation and hurricanes intensify with the changing climate, marine ecosystems may not always withhold resilience. Increased sediment and nutrient loads from runoff adversely impact coral reefs and other marine organisms. These marine resources are vital to the economy of the USVI, accounting for 80% of the gross domestic product and attracting millions of tourists annually. Marine resources such as coral reefs help protect residents from floods, storms and maintain high levels of marine biodiversity. The project partner, the USVI Department of Planning and Natural Resources - Coastal Zone Management currently uses in situ measurements and qualitative observations to monitor nearshore marine water quality. The analysis quantified water quality data post-hurricane season for Hurricane Hugo (1989), the 2017 hurricane season (Hurricanes Irma and Maria), and 2016 for baseline data using Landsat 5 Thematic Mapper (TM), Landsat 8 Operational Land Imager (OLI), and Sentinel-2 Multispectral Instrument (MSI) data. Using the select data, along with the 2017 NASA DEVELOP USVI Ecological Forecasting land use classifications (updated by Christopher McDonald), the team examined the complex interactions between hurricanes, land development, and water quality.