After more than eight years of controversy, a final decision on the Cape Wind development planned for Nantucket Sound will be made by the end of April, U.S. Secretary of the Interior Ken Salazar promised this week.

Mr. Salazar made the commitment after an exhaustive round of meetings in Washington on Wednesday involving all the major parties supporting and opposing the development, which would see 130 wind turbines, each more than 400 feet tall, placed in federal waters on Horseshoe Shoal in Nantucket Sound.

Mr. Salazar gave the parties until March 1 to reach a compromise agreement, failing which, he would act.

But the prospect of compromise remains remote. The main community group opposing the wind farm, the Alliance to Protect Nantucket Sound, used the forum to advocate moving the entire development out of Nantucket Sound to another site south of Tuckernuck Island, near Nantucket. The proponents of the wind farm resolutely refuse that alternative, which was considered and rejected in both the federal and state environmental assessments as being unfeasible.

It would be in deeper water, subject to more extreme wave action, require prohibitively long cabling to transfer the power to shore, and present new environmental problems and involve further extensive delays in vetting a project which already has been delayed a long time.

The Alliance proposal would, in any case, transfer the problem of visual impact away from Cape Cod and the north shores of the Vineyard and Nantucket to the south shores of Nantucket and the Vineyard.

Thus, while it might improve the views for opponents on the Cape and the Mashpee Wampanoag Tribe, it would do nothing for concerned Islanders and the Aquinnah Wampanoag tribe.

The Wampanoag Tribe of Gay Head (Aquinnah), whose objections to Cape Wind, along with those of the Mashpee tribe, emerged as the final stumbling block for the development, does not support the Tuckernuck option.

“We cannot commit to that,” said the Aquinnah tribe’s historic preservation officer, Bettina Washington, yesterday.

Wednesday’s meeting was prompted by an announcement last week from the National Parks Service that Nantucket Sound was eligible for listing on the National Register of Historic places.

It upheld a previous finding by the state Historic Preservation Officer, Brona Simon, supporting a claim by the tribes that the proposed wind farm would interfere with their spiritual ritual of greeting the rising sun.

The tribes argued the construction of 130 large turbines on Horseshoe Shoal would have significant archeological and historic impacts, because some 5,000 years ago, before it was inundated by rising sea levels (caused ironically by global warming), the area was dry land where Indians lived, hunted and buried their dead.

Approval of a cultural claim by American Indians over such a large area of water — some 500 square miles — is unprecedented.

After Wednesday’s round of consultations, the pro and anti forces held competing media conferences.

Cape Wind president Jim Gordon, opened his press conference by saying that he was convinced Secretary Salazar would approve Cape Wind.

He later stressed that the developers already had made significant concessions to opponents, including reducing the number of turbines form 170 to 130, reconfiguring the array to avoid submerged areas identified as potentially archeologically significant and to reduce the breadth of view from national historic landmarks, eliminating lighting to the greatest allowable extent, and agreeing to paint jobs which would minimize visibility.

In June 2009, the company had put forward a mitigation plan as part of the consultation process, to which the other parties had not responded.

“We have tried to be as reasonable as we can within the bounds of actually making the project move forward,” Mr. Gordon said.

“The only proposal the opponents have brought to date, and they did that in the meeting today, was recommending that we start from square one.”

He noted that the United States was now 20 years behind Europe in developing offshore wind, and that China had just installed its first offshore development, near Shanghai.

“And they started well after Cape Wind did,” Mr. Gordon said.

Barbara Hill, executive director of Clean Power Now, an advocacy group for Cape Wind, noted that Secretary Salazar was critical during the meeting of the long delays, and that the nine-year review process was “an example of government not functioning well.”

She said the alternative proposed by the Alliance was potentially more environmentally damaging than building at the current location.

“We would not at all be supportive of any consideration whatsoever of an alternative site.”

Nathanael Greene of the National Resources Defense Council, backed that environmental assessment and also portrayed approval of the project as a test of the Obama administration’s commitment to addressing climate change.

“If a project such as Cape Wind can’t get permitted and built, it’s clearly going to shake the confidence of investors in other countries around the world in our seriousness in addressing global warming and creating a clean energy economy,” he said.

Sue Reid, an attorney with the Conservation Law Foundation, said she took comments by Secretary Salazar in the meeting to mean that he recognized moving the project would entail starting the whole review process from scratch.

“We believe that the law and the environmental review dictate one result and that is that the project is approved with a lease in Nantucket Sound,” she said

The most pointed comment came from former state senator and now president of the Environmental League of Massachusetts, George Bachrach.

“What we are seeing now is the last gasp at a pathetic attempt by opponents whose only interest truly is Nimbyism, to enlist Indian tribes to front for them on an issue that has no merit,” he said.

The Alliance forces could not muster such a retinue of heavy hitters, nor such unanimity and certitude. The Aquinnah Wampanoag leaders, while they attended the Alliance media conference, do not endorse their compromise proposal.

Later, Ms. Washington said as far as the tribe was concerned, no compromise was possible, so long as there were potential impacts on Indian culture and heritage, and that applied also to the Tuckernuck plan, although, she said: “Realistically, if it came to a choice between here or there, we would have to make a call.”

She said she remained cautiously optimistic about the outcome. But regardless of which way it went, she was grateful that the tribes’ concerns were at last being accorded serious consideration.

“Secretary Salazar gave us an hour of his time and listened most closely to our concerns,” she said. “That itself was encouraging.”