Conserve Wildlife Blog

Award Winning Program Removes Rubble for Horseshoe Crabs

December 30th, 2019

reTURN the Favor Honored with 2019 New Jersey Governor’s Excellence Award

By: Meghan Kolk, Wildlife Biologist

Volunteers making piles of rubble at Seabreeze. Photo by Meghan Kolk.

Conserve Wildlife Foundation has been a partner in the reTURN the Favor (RTF) program since its establishment in 2013.  This multi-partner program organizes a large group of trained and dedicated volunteers who collectively spend thousands of hours covering miles of Delaware Bay beaches to rescue stranded horseshoe crabs.

This year RTF was honored with a New Jersey’s Governor’s Environmental Excellence Award, New Jersey’s premier awards program for recognizing outstanding environmental performance, programs and projects throughout the state, in the Healthy Ecosystems & Habitats Category.

RTF volunteers rescue horseshoe crabs from all sorts of precarious situations that would otherwise be deadly to contribute to the recovery of this important keystone species whose population plummeted after being overharvested in the 1990s. 

When horseshoe crabs come ashore to spawn they can easily be turned onto their backs by wave action, and if unable to overturn themselves become vulnerable to predation and desiccation in the hot sun.  The crabs also get themselves stuck in man-made hazards such as rubble, jetties, boat ramps, bin blocks or bulkheads.  Even natural impingement hazards such as vegetation, peat and overwash areas are detrimental to the crabs. 

The fate of shorebirds like the red knot, as well as the entire Delaware Bay ecosystem, relies on a robust population of horseshoe crabs and their eggs, so when RTF volunteers flip a crab they are contributing much more than simply saving the life of one crab.  This past season, the total number of crabs rescued overall soared to over 500,000 – that in itself is a significant contribution to conservation…but there’s more.

The second component of the RTF program is data collection.  Volunteers document the circumstance behind each crab rescued – was it simply overturned or was it impinged?  If it was impinged, the specific type of impingement is noted. All of this very specific data helps the coordinators of the program determine which beaches are the most hazardous for horseshoe crabs, and what the major issues are on those beaches. 

Beaches that are littered with rubble and other man-made obstacles are then targeted for possible habitat restoration.  The ideal spawning beach for a horseshoe crab is sandy and free of any obstacles that are potentially deadly. Horseshoe crabs are famous for getting hung up on just about anything! 

A habitat restoration could involve a large-scale project such as beach replenishment along with construction of an intertidal oyster reef to slow down beach erosion.  However, a project could also be as simple as just removing as much rubble as possible, and that’s where RTF comes in.  Again with the help of volunteers, RTF manages small-scale rubble removal projects that can make a big difference.

One such project was initiated last month at Seabreeze in Cumberland County, with the help of the U.S. Fish and Wildlife Service’s (USFWS) Partners for Fish and Wildlife program.  The rubble on this beach is the remnants of the small coastal community of Seabreeze, where the majority of houses were bought by the NJDEP Blue Acres program and torn down in 2010.  After failure of a sea wall that was built in 2006 and regular flooding of the homes and road due to higher tides from sea level rise and stronger storms, the homes could no longer be saved.  The rubble left behind after the demolition has been problematic for spawning horseshoe crabs ever since. 

Volunteers at Seabreeze. Photo by Laura Chamberlain.

On a calm and sunny day in November, RTF volunteers joined staff from CWF, USFWS, The Wetlands Institute and Western Hemisphere Shorebird Reserve Network (WHSRN) to begin the cleanup.  We focused on chucks of concrete that could manually be picked up off the surface of the beach.  Some larger pieces were split up into smaller, more manageable pieces.  The concrete pieces that were strewn across the beach were first collected into piles. 

A utility vehicle called a Mudd-Ox, towing a large wagon, made trips between these piles on the beach where we filled up the wagon to the dumpster where it was unloaded.  We continued this process until the dumpster was full.  Unfortunately, the dumpster only held about half of the rubble that should be removed, but we were extremely pleased with the results of the area we completed. 

The Mudd-Ox transporting rubble from the beach to the dumpster.
Photo by Meghan Kolk.

RTF plans to complete the second phase of the cleanup in the early spring, before the horseshoe crabs start coming ashore for the spawning season.  Based on the results of the first phase, the completed project will successfully create a suitable spawning beach that is much safer for horseshoe crabs (and safer for the RTF volunteers who cover this beach).  RTF’s 2020 data should reflect a reduction in impinged horseshoe crabs at Seabreeze, which is our ultimate goal for all of the beaches.  Stay tuned for Phase 2 this spring with before and after pictures.

The full dumpster at the end of the day. Photo by Meghan Kolk.

Funding for CWF’s work on this project was generously provided by ExxonMobil Foundation.

If you would like to get involved with reTURN the Favor, visit

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One Response to “Award Winning Program Removes Rubble for Horseshoe Crabs”

  1. Rick Weiman says:

    A wonderful project. Kudos to all the volunteers and their hard work.

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