MANY beaches are closed to summer bathers because of pollution. But the sandy expanse of Plum Island beach, an hour north of Boston, will close this summer for the opposite reason: It is the natural habitat of the piping plover, a small, sandy-colored bird that is nearing extinction. Because federal law protects the plover, the bird gets first choice on the beach, which also is a federal refuge for migratory birds in the Atlantic Ocean flyway.
The closure extends beyond Massachusetts. Three other refuges along the Atlantic Coast - Trustom Pond in Rhode Island, Forsyth Refuge in New Jersey, and Chincoteague Refuge in Virginia - will close all or parts of their beaches to protect the plover habitat.
In addition, piping plover nesting areas on many public and private beaches dotting the coast from New Brunswick, Canada, to North Carolina will be fully or partly closed for the summer, explains Anne Hecht, a biologist with the United States Fish and Wildlife Service's regional office in Boston.
Protecting the plover affects more Americans than protecting species like the California condor or bald eagle, says Ms. Hecht, who specializes in endangered species, because the plover lives in a more populated, more developed area along the Atlantic seaboard.
To many of the 40,000 to 80,000 beach-goers and surf fishermen who use Plum Island, closing the entire seven-mile stretch to protect fewer than a dozen pairs of piping plovers might seem extreme. But to the managers of Parker River Wildlife Refuge, the decision was unavoidable.
``Our primary mission is to protect wildlife. If recreation is compatible with that, and we can manage them both, then we will open the beach,'' says Jack Fillio, refuge manager. Since 1986, when the plover was first listed as a ``threatened species'' protected by the Endangered Species Act, portions of the beach have been closed.
This summer, however, will be the first that the whole beach, (except the island tip owned by the state), will be off-limits. Bird-watching areas and some nature trails will be open to the public.
Human activity is detrimental to the plover, says Mr. Fillio, for these reasons: People step on the camouflaged sand-speckled eggs; the presence of people scares hens from their nests, leaving the fragile eggs exposed to heat, cold, and foul weather. People also leave litter and food that attracts animals that feed on the plover, and they distract chicks that feed at the water's edge.
Roughly 700 pairs of plovers live along the Atlantic Coast, far fewer than there used to be, Fillio says. Only 10 pairs of plovers nested at Parker River Refuge last year; the summer before there were only three.
The refuge beach will be closed in future summers until the plover population reaches sustainable levels - roughly doubling to 1,400 pairs, Fillio says.
Success depends on the public's cooperation, he explains, unlike the efforts to protect endangered species in more remote places.
``The average person has an opportunity to help protect and recover the species,'' Fillio says, ``by being willing to respect closures, keep their pets leashed, and make sure they take their trash and garbage home with them.''
So far, public support for the closing has been strong, says assistant refuge manager Pat Martinkovic. But opponents are starting to squawk as summer approaches.
``I'm not very happy about it,'' says Kay Moulton, proprietor of a fish and tackle shop on Plum Island, and an avid beach-walker. ``I cannot see, for the life of me, the harm that a person could do just walking along the beach.'' The closure will hurt business, she says.
In Newburyport, Mass., the town nearest Plum Island, resident Mike Comacho vehemently defends the closure. ``I'm no environmentalist. But there has to be a balance. You have to let the experts decide. I do a lot of surf fishing, but if I can't fish there, I'll find some place else. The island is a perfect location for [the birds] to migrate to. Where else are they going to go?''