When red knots descend on the beaches of Delaware Bay this spring famished from their marathon flight toward the Canadian Arctic from the tip of South America, the rosy-breasted shorebirds may find slim pickings instead of the feast of horseshoe crab eggs they count on to fuel the rest of their migration.
Superstorm Sandy scrubbed away almost all the sand the crabs need to spawn upon. Restoring it in time is a top priority of wildlife groups beginning to repair Sandy's massive damage to dunes, beaches and salt marshes along the Eastern Seaboard that support a diverse population of birds, fish, marine organisms and other wildlife.
A recent report by the Manomet Center for Conservation Sciences and the National Fish and Wildlife Foundation predicts that the storm — which across the region washed away sand and vegetation that many species spawn in or call home, or polluted habitats with oil, sewage and other contaminants — is almost certain to have lasting effects on the recovery of the red knot.
The Delaware Bay could be called the Serengeti of the mid-Atlantic for the staggering numbers of birds there, said Eric Stiles, executive director of New Jersey Audubon. In addition to providing a wintering area for waterfowl that breed in the Great Plains of the United States and Canada, the estuary also provides a winter range for large numbers of raptors, including bald eagles.
"When I visited as a kid in the 70s, the beaches were green with horseshoe crab eggs," Stiles said. "When the birds took to flight, it looked like the whole beach was rising up en masse. Just a beautiful spectacle."
But at a popular New Jersey Audubon winter workshop on raptors of the bay, a time when participants usually see dozens of eagles and other birds of prey, "this year they only saw one eagle, one northern harrier, and one red-tailed hawk in the day outing," Stiles said. "The prey base has disappeared."
The rodents the raptors feed on will rebound quickly. But eelgrass beds that provide the primary food source for Atlantic brant and other waterfowl, as well as spawning areas for fish, will need restoration work where Sandy has buried the eelgrass under a foot of sand and sediment.
Other species identified in the Manomet Center report as priority candidates for habitat restoration include the roseate tern, piping plover, tricolored heron and least bittern. It found more than 70 sites from Massachusetts to Virginia that need restoration work, including beach replenishment, rebuilding of nesting islands and water control structures in managed wetlands.
Beach replenishment involves replacing land lost to storm erosion with sand pumped from offshore.
The projects, with an estimated price tag of $48.7 million, would not only repair late October's damage from Sandy, but also help coastal areas withstand major storms in the future. Some of the funding will come from the $50.5 billion emergency relief package signed by President Barack Obama on Tuesday; other money will come from state budgets or nonprofit organizations.
The report by the Manomet Center, based in Plymouth, Mass., recommends a $10 million project by the Army Corps of Engineers and other partners to repair the beaches of Delaware Bay, where the red knot's population has dropped from about 100,000 in the 1980s to about 30,000 now because of overharvesting of horseshoe crabs for fertilizer and fishing bait.
"These birds fly nonstop for thousands of miles from the tip of South America," Stiles said. "They land on Delaware Bay exhausted and emaciated, and then they double their body weight in 7 to 10 days foraging on horseshoe crab eggs before flying nonstop to the Arctic."
But the storm's sculpting work also created new habitat for species such as the threatened piping plover, a compact, pale shorebird with coloring that makes it all but vanish against the open sand flats where it nests.
The American Littoral Society's post-Sandy surveys found 67 percent of Mid-Atlantic beach areas had moderate to high damage to bird and marine life habitats, including vital marshes.
"These marshes are protein factories, providing rodents, crabs and other species in the food chain," said Tim Dillingham, the society's executive director.
The storm also washed raw sewage, oil and other pollutants into marshes, bays and estuaries, but the long-term impact isn't yet known, Dillingham said.
Scott Johnston, of the U.S. Fish and Wildlife Service's division of migratory birds, said that damage occurred from North Carolina to Cape Cod, but that the bulk of it was in New Jersey, Delaware Bay and Long Island Sound. As the rebuilding begins, he said, the focus should be to aim for the natural resiliency provided by natural dune systems and marshes.
Dillingham and other biologists said it would be more beneficial to create natural dune systems than to build bulkheads and seawalls to protect against future storm surges.
"An extensive dune system has the effect of protecting the homes and businesses while providing real and meaningful habitat," Dillingham said. "If the taxpayers are paying for this, they deserve more than a massive Berlin Wall."
Esch reported from Albany, N.Y.