PORTLAND – At least $3 billion is needed over five years to restore the environmental health of the Gulf of Maine, says a new report that’s described as the most comprehensive ecological needs assessment ever done for the gulf.

Two years in the making, the U.S. Gulf of Maine Habitat Restoration and Conservation Plan identifies the major environmental problems in the gulf, including habitat loss, pollution, climate change and the spread of invasive species. It also gives solutions for the problems and, for the first time, attaches costs to those solutions.

The Gulf of Maine Restoration Coalition led the effort, with help from federal and state agencies and nongovernmental organizations. The report was released Wednesday during a news conference at the Gulf of Maine Research Institute.

“In spite of the reputation for the Gulf of Maine as being a pristine environment, there are major problems affecting the economy and the quality of life here,” said Peter Alexander, director of the Gulf of Maine Restoration Coalition. “And if we’re going to get a handle on that, we have to throw a lot more money at it and a lot more resources.”

The Gulf of Maine, which stretches from Cape Cod to Nova Scotia, is one of the world’s most valuable and diverse ocean ecosystems, with rich fishing grounds and vast habitats that support businesses, recreational opportunities and tourism while adding to the region’s quality of life.

The report, which focuses on the U.S. — not the Canadian — portion of the gulf, is similar to environmental assessments that have been done for other waters, including Chesapeake Bay, the Great Lakes, Puget Sound and coastal Louisiana.

The next step is to persuade Congress to make the Gulf of Maine cleanup a congressionally authorized program that coordinates federal and state agencies to work together and funds the work, Alexander said.

It could take a couple of years to get funding, Alexander said, but he is confident given that other regions have received funding for their plans.

The report is a road map for restoration and conservation, said Curtis Fisher of the National Wildlife Federation, which has been participating in the initiative.

“The Gulf of Maine is a national treasure. It is a gem,” Fisher said. “We need to protect it and restore it and make sure there’s a conservation ethic that’s passed from generation to generation.”