EO-1 advanced land imager data in submerged aquatic vegetation mapping

Abstract

Submerged aquatic vegetation (SAV) habitats such as seagrass communities are among the most productive coastal habitats vital to estuarine ecosystems. Seagrasses serve a vital function in nutrient cycling, sediment stabilization, and maintaining water quality in the coastal zone (Newell and Koch, 2004; Larkum et al., 2006) and provide food and habitat for fi sh and other fauna (Heck et al., 1989, 1995; Hughes et al., 2002; Lazzari and Stone, 2006). The most prominent seagrass in the Northeast Atlantic region of the United States is eelgrass (Zostera marina L.), which grows in quiet embayments along the coast. Eelgrass has been deemed a critical marine resource and is currently protected by both Federal (Clean Water Act; 33 U.S.C. 26 Section 1251 et seq.) and state legislations (e.g., Long Island South Shore Estuary Reserve Comprehensive Management Plan). Even with this protection, eelgrass is declining in some areas. Seagrass communities are adversely affected by direct human impacts, such as eutrophication and physical damage from boating and fi shing, and indirect human impacts stemming from climate change, such as sea level rise and increased ultraviolet irradiance (Duarte, 2002). Increases in human population and changes in land use in the coastal zone contribute to increased nitrogen loading in estuaries and the effects of nitrogen loading on eelgrass have been extensively quantifi ed (Burkholder et al., 1992; Short and Burdick, 1996; Hauxwell et al., 2003). Additionally, the threat of climate change on seagrasses and coastal ecosystems through rising sea levels, increased temperatures, changes in water chemistry, and increased storm activity is expected to be severe (Short and Neckles, 1999; Orth et al., 2006). Inventory and monitoring are critical components in seagrass ecosystem management, restoration, and protection and provide key insights into the overall health of estuarine ecosystems.