ALBANY, N.Y. — 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.
Hurricane 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 in Plymouth, Mass., 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.’’
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 Obama on Tuesday; other money will come from state budgets or nonprofit organizations.
The report by the Manomet Center recommends a $10 million project by the Army Corps of Engineers and other partners to repair the beaches of Delaware Bay.