Make Your Own BRDs

Make a hatch that allows terrapins to escape from crab pots

  • Drowned Terrapins
    Drowned Terrapins   These 4 diamondback terrapins drowned after being trapped in a derelict crab pot.   Photo by Diane Tulipani.
  • Crab Pot
    Crab Pot   The type of crab pot that can trap diamondback terrapins. The gap at the top of this pot was opened by VIMS researchers during their attempts to remove the pot from the water and release the turtles trapped inside.   Photo by Diane Tulipani.
  • terp_in_water.jpg
      Diamondback terrapin (Malaclemys terrapin) photographed on the seaside of a barrier island on the Eastern Shore of Virginia.   Photo by Kevin R. Du Bois.
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Help prevent unnecessary deaths of diamondback terrapins and other animals in your crab pots. By simply attaching bycatch reduction devices (BRDs) to your crab pots, you can help preserve the diversity of animals within Chesapeake Bay for a healthier ecosystem, while still enjoying your blue-crab catch.

The Science of BRDs

There is a simple and low-cost way to prevent terrapins and other marine organisms—such as blue catfish, summer flounder, and striped bass—from getting into commercial-style crab pots. By attaching a bycatch reduction device (BRD) to each funnel opening, the majority of terrapins and other organism can be prevented from entering the pot. Studies have shown that while effective at preventing other animals from entering, BRDs have no impact on the size and number of blue crabs found in crab pots.

Scientists have determined that the most effective size for a BRD is 1 ¾" x 4 ¾". It can be made out of 11-gauge galvanized wire and a couple of  hog rings, then attached within each funnel opening with plastic cable ties or more hog rings.

To make and install your own BRDs:

Make Your Own BRDs

To make your own BRDs, you will need for each crab pot:

Hog rings. Illustration: (c) 2009 Kelly Finan / National Aquarium Pre-made BRD and zip-ties. Illustration: (c) 2009 Kelly Finan / National Aquarium
  • 11-gauge galvanized wire - 4 pieces x 14 ¾" length
  • 24 hog rings [(2 to form each BRD + 4 to attach BRD to pot) x4]
  • Marker
  • Needle-nose pliers
  • Wire cutters (optional)
  1. Take a single length of wire and, measuring from one end, mark at lengths 1 ¾", 6 ½", 8 ¼", and 13" from the end.
  2. Using the pliers, bend the wire to a 90° angle upward at each mark. The first and last lengths of 1 ¾" will overlap forming a rectangle of 1¾" x 4 ¾".
  3. Securely close the overlapping side with 2 hog rings. 
  4. Repeat for remaining 3 lengths of wire.

To install on a crab pot, position one BRD within each funnel opening and securely fasten to funnel with 4 hog rings per BRD; 1 at each corner of the BRD.

Install BRDs on the funnel openings of your crab pots. Illustrations: (c) 2009 Kelly Finan / National Aquarium. Install BRDs on the funnel openings of your crab pots. Illustration: (c) 2009 Kelly Finan / National Aquarium
Install BRDs on the funnel openings of your crab pots. Illustrations:
(c) 2009 Kelly Finan/National Aquarium.