When pack ice shifted to trap 33 commercial whaling ships off Alaska's Arctic coast in the fall of 1871, more than 1,200 people aboard the vessels had to be rescued. The costly and much-publicized debacle was, according to many historians, the beginning of the end for the Alaska commercial whaling industry.

A century and a half later, archaeologists studying the floor of the Chukchi Sea near the Inupiat village of Wainwright have found the wreckage of what appears to be two of the lost ships, the National Oceanic and Atmospheric Administration announced Wednesday.

The flattened hulls of the ships, along with some associated whaling equipment like anchors, fasteners and brick-lined pots that were used to render blubber into marketable oil, were discovered last fall by a NOAA archaeological team exploring the area with state-of-the-art sonar and sensing equipment.

It was remarkable to find the ship pieces and associated items so well-preserved, said Brad Barr, the chief scientist for the expedition carried out by the Maritime Heritage Program in NOAA's Office of National Marine Sanctuaries.

Normally, sea ice would be expected to scour and destroy the relics over time, he said. Instead, "We found artifacts that were just sitting there," he said.

The belief is that these items were protected from the icy element by a sandbar, remnants of which were discovered by the team, Barr said.

The discovery was made possible in large part by the retreat of sea ice and the advance of technology.

When the team mounted its expedition in late August and September, there was some floating ice at the mobilization site of Prudhoe Bay but wide-open water in the 30-mile stretch of the Chukchi where the underwater search was conducted, Barr said.

"We didn't see any ice in the Chukchi," he said.

That's a marked difference from September of 1871, when heavy ice trapped the whaling ships, crushing some of them and forcing those aboard to flee. Nobody died; the whalers and family members aboard the ships were evacuated, ultimately, to whence they came, which was Hawaii, San Francisco, New Bedford and other spots. Only one of the 33 ships was ever recovered. The others sank or were carried away, in various states of damage, by drifting ice.

People have long had clues about the general location where the ships went down, Barr said. Much of the debris has washed ashore over the years, and villagers have been able to use wooden timbers, metal pieces and other items for their own buildings onshore.

But this was the first underwater discovery, he said.

"This story has been known since 1871," he said. "It's just not been investigated -- that part of it has not been investigated -- before. People did not have the technology and the resources to do it."

Now that the wreckage and associated relics have been found, the best thing for them is to stay put, Barr said. In general, he said, marine archaeologists want shipwreck sites to remain in place, preserving their historic value.

"That's a sensible thing to do because once you move or remove it, you lose the archaeological information it can give you," he said.

He said he is not overly worried that the site will be disturbed. There are historic-preservation laws to protect it, and with Royal Dutch Shell ending its Chukchi Sea oil exploration program, "the real risk to those remains may be somewhat significantly reduced," he said.

Unlike the gold bullion or jewels that might draw treasure-hunters to other shipwreck sites, the anchors, chains and other relics at this site are items appropriate for a work vessel of its time, he said.

"They don't have any monetary value, but they have tremendous archaeological value," he said.

And the remoteness of the site offers its own protection. Even without sea ice, it is a faraway and difficult place to work, said Barr, whose team contended with high seas and stiff winds.

Still, there is enough concern about protecting the site that NOAA is not making public the precise location of the shipwreck discovery. Instead, the team has been giving all its information to the Alaska Office of History and Archaeology, the state agency tasked with preserving sites and relics in state territory, and the agency that issued the permit for the NOAA expedition.

Meanwhile, there are hints of more discoveries that could be made in the future.

Magnetic readings indicate that other metal-containing relics might lie beneath soil that has washed from the eroding shoreline onto the seafloor, he said.

The deeper waters near Point Barrow, an area where many other whaling ships were lodged in ice and lost in other incidents, is potentially fertile ground for future marine archaeological expeditions, he said.

"There may be wrecks up there that are more intact because they're out of the reach of the pack ice," he said.