ASSESSment of Earth and Ocean for Coral Promotion

EarthzineDEVELOP Summer 2014 VPS, DEVELOP Virtual Poster Session, Original

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The Tutuila Island in American Samoa contains a variety of land cover types surrounded by fringing coral reefs. Image Credit: American Samoa Oceans Team.

Project Team: American Samoa Oceans Team
Team Location: NASA Ames Research Center, Moffett Field, California

Aimee Teaby, Project Lead (California State University, Monterey Bay)
Jessica Sutton (University of South Carolina)
David Minovitz (California State University, Monterey Bay)
Lauren Makely (University of Washington)

Dr. Juan Torres-PÌ©rez (Bay Area Environmental Research Institute)
Dr. Liane Guild (NASA Ames Research Center)
Dr. Sherry Palacios (NASA Postdoctoral Program Fellow, Oak Ridge Affiliated Universities)
Dr. Cindy Schmidt (Bay Area Environmental Research Institute)

Land use changes, such as increased agriculture and urbanization, can greatly increase erosion and sediment loads reaching downstream water bodies. In coastal environments with steep terrain and small drainage basins, sedimentation directly influences the water quality in near-shore marine environments. Coral reef ecosystems are considered to be some of the most economically and ecologically important habitats in the world. Located in the South Pacific, American Samoa’s coral reef ecosystems provide benefits to the local economy estimated at approximately $5 million (U.S.) per year and support nearly 3,000 marine species. However, these reefs are at risk due to a number of anthropogenic impacts, including runoff and land-based pollution resulting in negative consequences to the local water quality. Indicators of poor water quality include elevated dissolved nutrients, which can promote fleshy algal overgrowth of corals and sedimentation, which reduces water transparency and interferes with photosynthesis by coral symbionts and increases metabolic costs. According to the American Samoa EPA’s 2014 Water Quality Assessment Report, 91 percent of evaluated rivers and streams and 60 percent of the coastal shoreline are impaired due to human activities. Population growth, land cover change, and increases in pollution and sedimentation have heavily affected the abundance, recruitment, and overall status of near-shore coral reef ecosystems. Traditional field and lab-based techniques used for determining water quality in streams and coastal ecosystems tend to produce temporally and/or spatially limited datasets despite the need of extensive field hours and manpower. The utilization of remote sensing in areas of limited resources and harsh terrain could improve upon the feasibility for continuous monitoring and management. The primary objective was to integrate geospatial observations of land cover change and ocean parameters from NASA assets to identify the linkage between land use and water quality. The project also provided site-specific implications for coral reef vulnerability in American Samoa through the spatial representation of water qualityåÊparameters. Land cover change was estimated using a supervised classification method on Landsat images from 2000 to 2014. Several ocean water quality parameters for near-shore marine environments were assessed using Landsat and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) imagery to identify areas of vulnerability. Final products were distributed to our partners, American Samoa Coral Reef Advisory Group, for improved water quality management and community outreach.




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