Post-Sandy beach restoration helps horseshoe crabs bounce back
A female horseshoe crab is hidden under a large number of smaller sized males. (Bas Slabbers for WHYY, file)
Work will start later this month on rebuilding horseshoe crab nesting grounds on two beaches on the Delaware Bay that lost tons of sand to Superstorm Sandy.
The work follows positive results at five beaches replenished after the 2012 storm, when wind and waves destroyed about 70 percent of horseshoe nesting grounds.
Eighty to 90 percent more eggs were laid on the replenished beaches as compared to unrestored beaches hit hard by Sandy, according to project leaders. Nesting rates at restored beaches were marginally better than at beaches considered largely unaffected by Sandy.
The American Littoral Society and the Conserve Wildlife Foundation of New Jersey led a coalition of conservation groups to replenish the beaches.
“The project is showing us that we can really be successful at helping to bring both the horseshoe crab populations and these threatened shorebirds back,” said the American Littoral Society’s executive director Tim Dillingham.
“(It’s) very rewarding to know that our stewardship is helping these species, which are really on the brink of extinction.”
Overharvesting in the 1990s drove down horseshoe crab numbers in the Delaware Bay. That led to declines in the now-threatened bird the red knot, which feeds on crab eggs during migratory stopovers.
Fearing another major blow to both populations if crabs were unable to nest during the spring of 2013, conservationists jumped to restore four New Jersey beaches in the months after Sandy.
Independent wildlife biologist Larry Niles, hired by the conservation groups to work on the replenishment, said it was not clear at the time if the project would work.
“We’re taking sand from a mine and putting it on the beach, and so we were concerned about the size of the grain of sand, and we were concerned about if there was enough moisture for egg development,” Niles said, “so there was a lot of uncertainties there.”
According to Niles, crab egg numbers ended up being higher in the spring of 2013, after Sandy, than in the year before the storm.
Conservation teams will rebuild three additional beaches next year.
WHYY is your source for fact-based, in-depth journalism and information. As a nonprofit organization, we rely on financial support from readers like you. Please give today.