Digital Extra

The work started at 6 in the morning, as a backhoe operator began scooping sand from the pond's edge. By 10 a.m., the breach was complete, as water from the pond rushed through the cut in the beach and emptied into the ocean.

Charles Hebert, manager of the Trustom Pond National Wildlife Refuge, said the Fish and Wildlife service usually breaches the pond in late March or early April every year, to improve water quality in the pond and expose mudflats, which provide foraging areas for migratory and nesting shorebirds.

Because of the oil spill - and the expected arrival of endangered piping plovers in a few weeks - the service decided to breach the pond early. The problem, said Hebert, is that oil from the spill remains in the soil at the fringes of the pond, where plovers and other birds like to poke around for food.

Hebert demonstrated the problem dramatically by stirring up the sand at the pond's edge with a shovel blade. A sheen of oil appeared on the water immediately.

"The oil is apparently bound up with some organic material in the sand," he said. "It's not very deep in the sand, but it hasn't dissipated the way we'd like."

Hebert said the breach will grow in width as the water flows from the pond and will carry much of the contaminated sand into the ocean. Once the level of the pond is lowered, most of the remaining contaminated sand will be exposed to wind and sun, which Hebert believes will help the trapped oil to evaporate.

Lowering the water level of the pond will also induce birds who like to forage at the pond's edge, such as plovers, to move to cleaner areas farther from the beach, Hebert said.

He said 12 pairs of plovers nested at Trustom Pond last year, and he expects the first plovers to return at the end of this month.

Hebert said there is not enough oil left in the pond and soil that will wash out into the ocean to adversely affect the water quality in the ocean or slow plans to reopen ocean fishing grounds that have been closed since the spill.

In general, said Hebert, conditions at Trustom Pond appear to be much better at nearby Card Ponds, where uncountable numbers of amphipods - tiny invertabrates crucial to the base of the food chain in the ponds - were found poisoned by the oil.

Card Ponds was doomed because the breachway through that beach was wide open when the North Cape barge went aground January 19, so oil was able to flow unimpeded into the ponds. At Trustom, the sands of Moonstone acted as a partial barrier.

"What we've looked at (in Trustom) doesn't show anything close to the extent of injury Card Ponds suffered," said Hebert. "Card Ponds just got shocked with a high volume of highly toxic oil."

Hebert said the pond has to be breached periodically anyway, or else pollution builds up in the form of excess nitrogen - primarily from bird droppings, but also from seepage from residential septic systems and fertilizer runoff from farms.

With the pond breached, ocean water flows in on the high tides, adding clean water and a measure of salinity crucial to the lives of various plants and animals that inhabit the waters.

Hebert said he expects the breach to remain open for about two weeks before sand builds up naturally and closes it again.