Ghost Pot Detection and Removal Through Low-Cost Sidescan Applications

• Jared Wierzbicki, Mechanical Engineering, University of Delaware

• Arthur Trembanis, College of Earth, Ocean and Environmental Science, University of Delaware

Crabbing is a staple activity for Delaware fishers, oftentimes involving the utilization of crab pots to lure and trap the animals. These crab pots have a buoy attached to them, making it easy to identify and recover the trap.  The buoy often gets separated from the pot, creating what are called “Ghost Pots,” which are very difficult to recover. Animals are attracted to ghost pots due to the bait inside of them and die, which hurts species populations, harms local habitats, and causes less crab yields in active crab pots within the area. Delaware Sea Grant and University of Delaware have created a project dedicated to recovering derelict crab pots from the Delaware Inland bays, locating the pots with sidescan sonar and marking their location with GPS. Since derelict crab pots are made of metal, they shine brightly when viewed under acoustic imaging, making side scan is the best way to identify and mark these pots. With such a large search area to cover, volunteers have been selected to run side scan sonar on their boats. Implementation of sonar systems, however, typically involves lasting or permanent changes to a volunteer’s boat, such as drilling directly into the frame or internal wiring of electronics. Since the side scan sonar needs to be easily swapped from one volunteer boat to another, a low-cost, portable, user-friendly sidescan sonar system that does not require permanent modification to the volunteer boats needed to be developed. The objective of this project is to construct a prototype side scan travel kit that will be used to create a lending library of sonars for volunteer use. Development of the travel kit will lower the barrier of entry for volunteer boats to participate in side scan surveying, allowing for more efficient mapping of the Delaware Inland Bays.