WASHINGTON — The Obama administration on Wednesday took a significant step toward allowing oil and natural gas companies to drill off the coasts of Virginia and other Atlantic Seaboard states.

Interior Secretary Ken Salazar announced a plan to allow companies to conduct seismic mapping surveys on the outer continental shelf of the coast from Delaware to the middle of Florida.

“As part of our offshore energy strategy, we want to open the opportunity . . . to conduct seismic exploration . . . so we can know what resources exist in those areas,” Salazar said in Norfolk. “The fact is our information is . . . 30 years old, and it’s out of date. The bottom line is it’s an important safe step to understand what resources are out there.”

In addition to assessing how much oil and natural gas is in the area, seismic testing would help determine the best places for wind turbines and other renewable energy projects, locate sand and gravel for restoring eroding coastal areas and identify cultural artifacts such as historic sunken ships.

Virginia Gov. Robert McDonnell, in a statement, praised the announcement as “a small step forward in the development of our offshore energy resources.” But he also chided the administration for not allowing oil exploration off Virginia last year, a “breakthrough that would have led to the creation of thousands of new jobs in our state, generated significant revenues for state and loca l governments, and led to more domestic energy production.”

Environmental groups attacked the survey proposal, saying the sonic booms could injure hundreds of thousands of dolphins and whales and disrupt the feeding, mating and reproductive patterns of marine mammals millions of times each year.

“They’re acoustic animals. They’ve evolved over millions of years,” said Michael Jasny, a senior analyst for the Natural Resources Defence Council. “To take away their ability to hear, to damage their ears could be like a death sentence.”

“Why explore when we don’t want drilling in the first place?” asked Eileen Levandoski, a Virginia Beach resident who works for the Sierra Club’s Virginia chapter. “While the ÞGulf of Mexicoå and its people are today still reeling from the BP Gulf oil spill disaster, there are huge incidents right now occurring off the coast of Scotland in the North Sea and off the Brazilian coast. The risk continues to be real and formidable.”

The Bureau of Ocean Energy Management has received about 10 requests for permits from companies that conduct seismic surveys and sell the data to oil companies. Seismic surveys map hundreds of miles of ocean with acoustic waves that reveal contours of the ocean floor.

Surveys could begin early next year. Before that happens, BOEM will hold public hearings in Annapolis, Md.; Norfolk, Va.; Savannah, Ga., and five other cities along the coast. Public comment is scheduled to end May 30, and the process of incorporating the testimony and finalizing the plan will take the rest of the year.

McDonnell’s government said 80 percent of Virginians support offshore oil and gas exploration. The governor said that not allowing exploration last year pushed back any possibility of lease sales to 2018, at the earliest, and he said $4-a-gallon gasoline prices are evidence that exploration is needed.

Salazar, echoing Obama and economic experts, said that “there is no silver bullet for high gas prices” and that current domestic gas production is higher than any time in the last eight years.

“I’m proud of the progress that we’ve made over the last three years, domestic gas and oil production is up, foreign imports of oil are down,” Salazar said. “In fact, imports of oil decreased by a million barrels a day in the last year alone.”

Tommy Beaudreau, director of BOEM, said planning surveys takes time. “Seismic surveys are important . . . but you need to be careful to manage the potential environmental effects, including effects on marine mammals.”

Jasny said those effects will be significant. He said that the technique has been used in many waters and that “seismic air guns have an enormous environmental footprint.

“Humpback whales and fin whales, both endangered, have been shown to fall silent and abandon habitat over areas of hundreds of thousands of square miles. Fish have been displaced over vast areas.

“Fishermen have complained for years about losses in catch,” he said.

Staff writer Anita Kumar contributed to this report.