Horseshoe Crab Conservation Programs and Initiatives

In the absence of human interference, horseshoe crabs have successfully evolved for over 475 million years. ERDG has made a commitment to protect this remarkable mariner who plays a vital role in nature’s delicately balanced food web and whose life-sustaining contributions to humanity have yet to be fully realized. We believe that the foundation of a successful conservation program is effective public education and coastal community support, in conjunction with conservation initiatives, both terrestrial and aquatic, that preserve essential habitat and minimize human impact.

International Union for the Conservation of Nature (IUCN) Species Survival Commission (SSC) Horseshoe Crab Specialist Group:

Founding member and Chair of the “Trade Industry & Use” work group

The Science and Conservation of Horseshoe Crabs:

Founding member and steering committee support for this series of international workshops.

Annual Spawning Survey

In collaborated with scientists from the USGS Biological Resources Division, ERDG actively participates in the annual horseshoe crab spawning survey, designed to compile reliable population data along the shores of Delaware Bay.

Spawning Mortality

In 1998, ERDG launched its highly successful Just flip ’em!™ Program to bring attention to the high mortality horseshoe crabs (Limulus polyphemus) incur from being stranded up-side-down during spawning and to encourage, through a simple act of compassion, an appreciation for this remarkable creature who will not survive our indifference.

“The common occurrence of stranded horseshoe crabs during breeding season spurred the Just flip ‘em!™ program on Delaware beaches; beyond this being a ‘humane’ action, the Botton & Loveland (1989) study provides the rationale.”
– Dr. Carl N. Shuster, Jr., 1999

Reducing the Impact of Shoreline Development and Habitat Loss

The future survival of the world’s four extant horseshoe crab species will ultimately depend upon the preservation of its spawning and nursery habitat, both marine and terrestrial — a challenging prospect in light of the ever-increasing human density along the same beaches and near shore areas where horseshoe crabs spawn and grow.

  • Backyard Stewardship™
    in 1999 ERDG launched its Backyard Stewardship™ community based horseshoe crab sanctuary program, designed to encourage coastal communities to declare their shared habitat a horseshoe crab conservation area or sanctuary. On June 13th, 2000, then Delaware Governor Thomas Carper visited Broadkill Beach, Delaware to recognize this community for working with ERDG in establishing Delaware’s first community based horseshoe crab sanctuary.
    ERDG is the only organization that has been successful in convincing residential landowners to designate their private beaches as horseshoe crab sanctuaries. In addition to Broadkill Beach, ERDG has also enrolled the Delaware bayshore communities of Pickering Beach, Kitts Hummock, Slaughter Beach, Prime Hook National Wildlife Refuge (Fowler Beach), Prime Hook Beach and Camp Arrowhead on Rehoboth Bay. ERDG has also enrolled the New Jersey bayshore communities of Fortescue, Gandy’s Beach and Money Island. ERDG is currently working to establish additional horseshoe crab conservation areas within communities throughout the Atlantic Coast of the United States. To date over 20 miles of some of the most productive horseshoe crab spawning beaches in the world has been protected through this program. Ultimately, our goal is to protect horseshoe crab spawning habitat throughout out the species spawning range worldwide.
  • Pickering Beach Stranding Mitigation Project
    In the spring of 2018, in an attempt to mitigate mass horseshoe crab standing mortality at the North end of Pickering Beach, Delaware, caused by beach erosion and shoreline topographical changes in a particular area, ERDG installed a 350 foot temporary wooden barrier, across a stretch of beach, blocking spawning horseshoe crabs from entering a backwash that traps thousands each year. This simple, but effective barrier was removed after the spawning season to permit natural modeling of the beach, which occurs throughout the year. In 2019, joined by local volunteers and the Veterans Conservation Corps the barrier was reinstalled with similar success. In 2020, although hampered by Covid-19 social distancing requirements, a small group of ERDG volunteers reinstalled the fence, once again saving thousands of horseshoe crabs

Reducing Dependance Upon Horseshoe Crabs for Bacterial Endotoxin Testing

To clearly delineate the problems surrounding the continued harvest of three of the world’s four horseshoe crab species for the production of bacterial endotoxin tests (BET) and to raise awareness within the global health care industry on how they can become a driving force behind horseshoe crab conservation, our “Protecting Health” section was created.

Reducing Dependance Upon Horseshoe Crabs as Bait

In 1999 ERDG initiated the first study to test the effectiveness of bait bags in reducing the demand on horseshoe crabs used as bait in the conch and eel fishery. ERDG working with the Virginia Institute of Marine Science (VIMS) and a select group of Virginia conch fishermen, demonstrated that bait needs could be reduced by half without a measurable loss in catch if placed within a bait bag. This is possible because bait bags significantly reduces secondary predation on the bait. At the time, a coast-wide harvest of horseshoe crabs as bait exceeded 3.5 million animals annually. A potential reduction of 50 percent represented a significant conservation measure and one that ERDG worked to see adopted throughout the industry. As a result of this study and ERDG’s program to produce, distribute and promote the use of bait bags free of charge to over 15,000 conch and eel fisherman along the US Atlantic Coast, this bait saving device is now an industry standard. In addition to our bait saving initiative, ERDG continues to conduct research and seek partners who can produce, distribute and promote a viable bait alternative to horseshoe crabs.

  • ERDG seeks partnerships with existing commercial synthetic bait manufacturers for the development of an alternative bait. (pdf)
  • Alternative Gear and Supplemental Bait Workshop, March 3, 2004 (pdf)
  • Decrease in Crabs Raises Concerns (pdf)
  • ERDG completes Phase II of its bait bag initiative (pdf)
  • Horseshoe Crab Bait Bags are adopted by the Virginia Conch Fishery (link)
  • ERDG begins Phase I of its Bait Bag Initiative (link)
  • Alternative Bait Workshop (minutes)

Conservation Resource Information

Our Conservation section provides a comprehensive list of regulatory agencies and NGO’s involved in the conservation of the world’s four horseshoe crab species, as well as an online library of ideas and resources for organizations and people interested in horseshoe crab conservation and education.