This article was originally published in The New York Times Green Blog on January 4, 2013. It was written by Jon Hurdle. View the original article here.

Conservationists are warning that swift action is needed to repair mid-Atlantic bird refuges that were badly damaged by Hurricane Sandy.

In a report issued on Thursday, researchers at the National Fish and Wildlife Foundation and the Manomet Center for Conservation Sciences said that beaches should be replenished, nesting islands rebuilt and water-control structures in managed wetlands repaired to recreate the right conditions for threatened or endangered species to breed or migrate during the coming spring and summer.

The organizations identified more than 70 sites from Massachusetts to Virginia that need to be restored, at a combined estimated cost of $48.7 million. Such projects would be intended not only to repair the damage from the hurricane but also to allow coastal areas to withstand future major storms.

“Hurricane Sandy did significant damage to some long-term conservation work,” Stephen Brown, director of the shorebird science division at the Manomet Center, said in a statement. “Important habitats for high-priority species have been altered by this storm.”

Among the bird havens damaged was the Reeds Beach area on the New Jersey side of the Delaware Bay, where migrating shorebirds like the red knot rest and feed en route to breeding grounds in the Canadian Arctic, the report said.

Hurricane Sandy devastated the beaches there, leaving almost no sand for the spring spawning of horseshoe crabs, on whose eggs birds like the red knot feed, according to the report, which was based on information from state and federal agencies and private organizations like the National Audubon Society.

Without the crab eggs that allow the knots to replenish fat stores during their 10,000-mile annual migration from southern Argentina, they won’t be able to breed, the report warned. This has worrisome implications for the survival of the species, whose numbers have dropped sharply in the last two decades because of the overharvesting of horseshoe crabs.

“This latest event is almost certain to have lasting effects on the recovery of this bird,” the report said.

Other high-priority species identified by the report, some of which are already protected by state and federal agencies, include the piping plover, the tricolored heron and the least bittern.

The biggest project identified by the study is a $20 million proposal to repair damage to the Prime Hook National Wildlife Refuge in southern Delaware, an important center for migratory birds where rising seas had invaded freshwater coastal impoundments even before Hurricane Sandy hit.

The proposals advanced in the report are separate from a long-term plan to restore the coastal marsh and repair breached sand dunes at Prime Hook, which the federal Fish and Wildlife Service made final in late December.

At the Jamaica Bay Wildlife Refuge in New York City, the new report calls for $2 million to repair beaches where erosion led to saltwater intrusion of freshwater ponds.

But Hurricane Sandy wasn’t all bad news for bird habitats, the report said. The storm actually created some new nesting and roosting sites for species that need open sand.

While calling for the renourishment of beaches that lost significant quantities of sand during the storm, the report warned against moving sand from other areas that support species of birds and fish. Taking the material from those areas would simply mean damaging another location, it said.

David McGlinchey, a spokesman for the Massachusetts-based Manomet Center, said that spending priorities should be governed by the greatest “biological return” on the investment, particularly for rare coastal species.

An example, he said, would be maintaining or creating habitat for roseate terns, which need small, sandy islands for nesting.