Not all the news from the environmental front is bad. The breeding colony of least terns at Chincoteague National Wildlife Refuge, wiped out in 1972 by storm tides, is thriving again.

Refuge personnel are proud as new parents of the colony, which was reestablished by persistnce, careful observation and only a modest outlay of tax money.

Life was tough enough for the swallow-sized tern in the days when just the occasional India roamed the bare beaches it nest on. "Nest" is too fancy a word for the shallow scrapes it makes in the sand to lay its pair of speckled-dun eggs. If a storm tide washes out one clutch the terns will try again, but reproduction is iffy at best.

These days, of course, virtually every ocean beach in its range of Massachusetts to Texas is either covered with cottages and condominiums or churned by four-wheel drivers, and the least tern's status is drifting from "threatened" toward "endangered."

"They've been nesting on Tom's Cove Hook here since before the refuge was established," Chincoteague biologist Ed Britton said. "After the 1972 disaster the remnant birds tried to make a comeback, but they were just limping along. We tried all sorts of thing: posts to keep out beach vehicles, then fencing to keep out beach-combers. Last year we planted beach grass in the 10-acre enclosure, built water barries out of old tires, piled up oyster shells, put out decoys and even broadcast recorded bird calls to pull them in."

It worked fine, up to a point. Then pairs of terns nested, but although they tried an average of twice each, red foxes ate 79 percent of the clutches.

This year the fence was electrified, and that did the trick: At last count the enclosure had produced 181 least tern nests, plus 31 nestings by common terns, 10 by piping plovers, five by American oystercatchers and three by willets. No hen ever watched her chicks more anxiously than Britton and his associates, and they are happy to report that fox and raccoon raids has destroyed fewer than a dozen nests and only a handful of young birds.

The tern nursery is visited two or three times a day. Each nest is marked and plotted, with notes made of egg production, washouts, hatchings and so forth. Refuge workers "ride fence" on the enclosure as they patrol the beach, because the wires are frequently broken by deer and occasionally by raccoons and foxes that, having been jolted on the way in, are frantic to break out.

Britton pointed out several new-hatched chicks to a visitor, who never would have seen them otherwise, so tiny and sand-colored are they. That such bits of fluff could survive hot sun and cold winds seems incredible. "The parents are pretty faithful, both sexes sharing brooding and feeding, and the chicks grow fast," Britton said. "In a week that little guy will be running faster than you can; in two weeks he'll be flying and foraging for himself; and in three weeks he'll be ready to migrate."

That is, assuming that during the first week he doesn't get run down by a four wheeler while testing out his legs. "Sometimes they get into tracks that are too deep to climb out of, and the next vehicle along gets them," Britton said.

But, all things considered, the mortality at Chincoteague is probably far less than on a wild beach, and it should be even better next year, the good Lord willing and the tide don't rise, when this year's crop comes back to find the stronger fence and other refinements that are planned. Terns tend to nest close to where they were hatched, and the 1979 crop should also capture passing displaced birds, because nothing makes a beach more attractive to a pair of terns than lots of other nesting terns.

About the only question that has not been resolved is where this year's 115 pairs of breeding birds came from, since last year's "class" was nearly all eaten. "We probably got a few from Wallops Island, where they had bad tides," Britton said. "But that doesn't seem to account for this spectacular turnout." The refuge asks anyone who sees least terns nesting along the Eastern Shore -- or not nesting where they have been seen before -- to report all sightings to the adminstrative office: 804/336-6122.

Birders who would like to see the colony should hustle on down to Chincoteague, because the last birds will be heading south in a few weeks. CAPTION: Picture, A TERN ON THE BEACH. By Al Steiner.