Assessing and Managing Prop Scar Damage to Seagrass in Texas
The State of Texas established the Redfish Bay State Scientific Area with the goal of protecting and studying native seagrasses. Boating activity had already caused extensive prop scarring in the bay's seagrass meadows. Information on the extent of this damage was needed to assess and monitor the success of various management strategies developed to minimize this damage.
Because field assessment of prop scarring is difficult and time-consuming, remote sensing, specifically digital camera imagery, was used to locate areas of scarring, determine the extent of the scarring, and support automated processes for mapping prop scars. High-resolution (1/4 meter) ADS-52 imagery was collected under ideal conditions for prop scar mapping. Feature analysis, classification and regression tree analysis, and image segmentation routines were all used to generate prop scar maps.
The Texas Parks and Wildlife Department is using this information to update its prop scar mapping methods and improve its estimates of the amount of actual prop scarring in Redfish Bay.