The Tampa Harbor General Re-Evaluation Study evaluated the widening of Cuts A and B of the Tampa Bay Entrance Channel. USACE Jacksonville District contracted ANAMAR to collect, analyze, and ground-truth sidescan sonar data to identify potential hardbottom resources near the existing channel.
ANAMAR collected high-frequency sidescan sonar data along each side of Cuts A and B, with coverage extending >300 feet from the toe of the channel. Sidescan range was limited to 25 meters to capture high-resolution imagery capable of ensonifying a 1-meter target with a minimum of three acoustic pings, enabling positive identification of smaller features (e.g., car tires). A differential GPS system was used for navigation; and coverage was 200%.
ANAMAR’s scientific diving team was deployed to field-verify representative classes of targets to complete the mapping and classification of hardbottom resources. The dive team documented significant areas with productive hardbottom. After comparing diver observations at each site with sidescan sonar images of the target, areas of hardbottom could be delineated on the sonar images to provide the approximate extent of hardbottom resources within the project area. This was used to determine which area of the channel could be widened while avoiding and minimizing impact to the established hardbottom resources. Additional studies will evaluate the extent of the resources and collect data to provide the appropriate mitigation to offset habitat loss due to construction activities.