BOSTON – New England lakes and streams have been comparatively unsuccessful in recovering from the effects of acid rain, according to a report released Wednesday.

The amount of acid found in precipitation in New England fell 30 percent during the 1990s, compared to a 40 percent drop nationwide. But even the smaller reduction here did not translate into a significant decline in the number of acidic lakes or streams, according to the Environmental Protection Agency.

The number of “acidic systems” in the region fell just 2 percent from 386 lakes to 374, or about 5.5 percent of the total number in the region. Most other regions experienced sharp declines.

The number of acidic lakes in the Upper Midwest fell 68 percent from 251 to 80, or less than 1 percent of the total. The number of acidic lakes in the Adirondacks and Northern Appalachians fell 38 percent and 28 percent, respectively.

Mike Kenyon, the air programs branch chief at the EPA’s regional office, said the report doesn’t explain why New England’s ecology is slower to adjust, but says one leading theory is that years of acid rain damaged the ecosystem’s ability to bounce back.

“The soil’s lost its ability to neutralize acids and the recovery’s going to take longer,” he said.

The report shows a need to cut back further on pollutants that cause acid rain, Kenyon said.

“Perhaps part of the message is we’re seeing the first signs of recovery in other areas of the country,” he said. “It’s apparent that an acid rain type program can work. In order to see significant reductions, further reductions are needed.”

Steve Kahl, director of the Senator George J. Mitchell Center for Environmental and Watershed Research at the University of Maine, led the EPA research effort in New England and helped to lead the team that wrote the report.

He said data in New England came from about 100 lakes in Maine and another 286 in New England.

“The report emphasizes that there are significant uncertainties in our understanding of processes related to recovery of acidic lakes, and that research needs to continue for us to understand the effectiveness of the Clean Air Act and any future amendments,” Kahl said.

The report, once fully digested, is likely to be used as evidence both by those supporting and opposing President Bush’s “Clear Skies” anti-pollution initiative.

The Clear Skies proposal -which the administration claims will reduce power plant emissions 70 percent over 15 years – would lead to the reductions New England’s lakes and streams need, Kenyon said.

But David Doniger, policy director of the climate center at the National Resources Defense Council in Washington, said the report shows stronger steps need to be taken. Environmentalists have sharply criticized the Clear Skies proposal, calling it a rollback that would lead to significantly more pollution.

“What I believe this is telling us is the air pollution has not been reduced enough to solve the acid rain problem,” he said. “We need to cut it much further, much faster.”

Doniger called the EPA’s release of the report “part of the sales pitch for the president’s air pollution plan.”