Application of single-beam acoustics to macro-algae bloom management

Delaware´s inland bays are shallow enclosed estuaries located behind barrier beaches with limited tidal flushing. These bays (Rehoboth, Indian River and Little Assawoman) are experiencing increased recreational usage. Nutrient loading of the bays is increasing. This increased nutrient load has caused extensive blooms of macro algae of the Ulva genus. This alga is uprooted from the bottom by storms and distributed along shore in huge deposits. As these mats of algae decay they cause breathing problems and an odor nuisance. Oxygen depletion results in fish kills. An algae harvesting program has been started. A remote sensing effort to map benthic habitats of Rehoboth Bay has also been commenced. This project will support planning of the algae harvest, determining the location and extent of the algae, and also provide a more detailed shallow water bathymetry of the bay than currently exists. A sonar mapping program is also in existence