Geospatial Video Monitoring of Benthic Habitats Using the Shallow-Water Positioning System (SWaPS)

In this project, we describe the application of a geospatial video-based survey technique, the Shallow-Water Positioning System (SWaPS), develop by scientists from NOAA´s National Geodetic Survey, to document the abundance, distribution, and damage patterns of benthic organisms in shallow marine habitats that have been historically under-represented in monitoring programs due to the difficulties associated with boat access. SWaPS uses a GPS receiver attached to a video camera. The GPS receiver is centered over the digital video camera that is suspended over a glass enclosure that provides a down-looking view of the bottom. SWaPS is presently available in three platforms used for distinct survey requirements: (a) a boat-based system; (b) a remotely-operated system; and (c) a diver-based system. During the surveys, each video frame recorded is stamped with position information, date, depth, heading, and pitch and roll, and the georeferenced digital frames obtained in these surveys can be easily analyzed to document patterns of abundance and distribution of submerged aquatic vegetation (SAV) and other benthic organisms, as well as damage patterns caused by ship groundings and boat propellers in shallow coastal habitats. The SWaPS methodology provides a fast, spatially precise alternative to diver-based surveys that can be especially useful when: (1) a large number of closely spaced sites need to be surveyed rapidly; (2) field time is limited, as is often the case prior to the onset of an acute disturbance (e.g., hurricane, dredging project); (3) the availability of trained field personnel is limited; (4) resources need to be precisely mapped; (5) a permanent visual archive of the extent and condition of benthic resources is needed; and (6) the same locations need to be surveyed repeatedly without establishing permanent markers. Field surveys using SWaPS can be easily conducted by operators without scientific training, thereby removing the need for specialized field pe- rsonnel and reducing the cost of field operations.