An assessment of seagrass and tidal flat recovery from anthropogenic physical disturbance events along the Padre Island National Seashore

Propeller scars and off-road vehicle (ORV) tracks are readily visible in aerial photographs and their areal extent can be easily measured using the latest techniques in GIS technology. The objectives of my study were to establish a baseline of seagrass and wind-tidal flat scarring along the Padre Island National Seashore for future monitoring, to determine the persistence of wind-tidal flat ORV tracks from historical aerial photographs, and to examine the recovery of seagrass propeller scars by comparing 2002 and 2005 aerial photographs. Over the area examined, the total number of propeller scars decreased 29%, and the total number of ORV tracks increased 28% between 2002 and 2005. Propeller scars appeared to take less than three years to recover. Historical photograph analysis showed that ORV tracks have persisted in the wind-tidal flats since the 1960's and show no sign of recovery. This work represents the first attempt to measure seagrass and tidal flat scarring intensity and recovery time from physical disturbances in the Padre Island National Seashore.