Delaware Sea Grant is part of the National Sea Grant Program, a federal-university partnership between the National Oceanic and Atmospheric Administration (NOAA) and 34 universities in every coastal and Great Lakes state, Puerto Rico, and Guam. Delaware Sea Grant is housed within the University of Delaware, and they work to ensure Delaware’s coasts are sustainable, resilient, and healthy. Delaware Sea Grant has removed 571 derelict traps since beginning this work in 2020. 

As a project partner of the National TRAP program, Delaware Sea Grant and the University of Delaware work to retrieve recreational blue crab traps from the Delaware Inland Bays – three shallow interconnected coastal lagoons with a narrow barrier island separating them from the Atlantic Ocean. Preliminary data from the University of Delaware estimates there are between 20,000 and 30,000 derelict blue crab pots in the 34-square mile area. With an average depth between 5-10 feet, derelict traps pose a major navigational hazard to boaters. During the summer months, the population of the area doubles as an influx of tourists come for swimming, fishing, and crabbing. Recreational crabbers must obtain a fishing license, check on traps every 72 hours, and install bycatch reduction devices on each trap. However, initial research suggests that approximately 15% of traps are not being checked regularly and at least 25% of traps do not have a bycatch reduction device installed. Blue crabs are most commonly found in derelict traps along with oyster toadfish, spider crabs, and clams. 

Four crews divide and conquer the retrieval efforts. First, a boat equipped with side scan sonar, called the “mobile mapping unit,” charts a target section of the estuary. The sonar data is run through an artificial intelligence (AI) crab pot detector program developed by a researcher at the University of Delaware to create a map of traps underwater. Then, those maps are handed off to the marking crews who drive their boats to the trap locations and attach a buoy. Up next, the hauling crews navigate to the buoy locations and use a grapple device to haul the traps out of the water. This is no easy feat as most traps are covered in mud and extremely heavy. Once the boat is full of traps, they drop them off at shore where the land-based crew power wash the traps and assess if the traps can be reused or if they should be recycled. With this approach, Delaware Sea Grant has retrieved 120 blue crab traps and has more retrieval days planned through April 2026!

Delaware Sea Grant has a strong, dedicated team of volunteers that help make their trap removals successful. During a recent two-day retrieval effort, 50 volunteers with nine recreational boats teamed up for the physically demanding task. Although it is hard work, volunteers including retirees, recreational boaters, and University of Delaware students are always seen smiling and laughing. One of Delaware Sea Grant’s goals is to prevent future traps from becoming derelict by educating recreational crabbers on alternative crabbing methods (such as a chicken neck on a string!) and how to properly equip and set crab pots. Additionally, Delaware Sea Grant has developed a life-sized derelict crab pot game for K-12 students, and the University of Delaware is publishing research on the economic impacts of ghost fishing on the blue crab fishery. The study found that “based on the total number of pots present and crab collected we estimate that $92,272.44 (approximately 139,806.70 crabs) is lost over a 4 month period due to the presence of 328 derelict pots in our three sampling sites alone (80 hectares).” (Ferris et al. Submitted)