Actual drilling of test wells could not begin until a White House ban on production in the Atlantic expires in 2017, and even then, only after the government agrees to lease ocean tracts to oil companies, an issue officials have barely begun to study.

The petroleum industry has sunk 51 wells off the East Coast — none of them successful enough to begin production — in decades past. But the Interior Department said in 2011 that 3.3 billion barrels of recoverable oil and 312 trillion cubic feet of natural gas could lie in the exploration area, and nine companies have already applied for permits to begin surveys.

President Obama committed in 2010 to allowing oil and gas surveys along the same stretch of the Atlantic, and the government had planned to lease tracts off the Virginia coast for exploration in 2011. But those plans collapsed after the Deepwater Horizon oil rig disaster in April 2010, and the government later banned activity in the area until 2017.

Thirty-four species of whales and dolphins, including six endangered whales, live in the survey area. Environmental activists say seismic exploration could deeply imperil blue and humpback whales as well as the North American right whale, which numbers in the hundreds.

Surveys generally use compressed-air guns that produce repeated bursts of sound as loud as a howitzer, often for weeks or months on end. The Interior Department’s estimate said that up to 27,000 dolphins and 4,600 whales could die or be injured annually during exploration periods, and that three million more would suffer various behavioral changes.

But many scientists say death and injury are not a major concern. Decades of seismic exploration worldwide have yet to yield a confirmed whale death, the government says.

“It is quite unlikely that most sounds, in realistic scenarios, will directly cause injury or mortality to marine mammals,” Brandon Southall, perhaps the best-known expert on the issue, wrote in an email exchange. “Most of the issues now really have to do with what are the sublethal effects — what are the changes in behavior that may happen.” Dr. Southall is president of SEA Incorporated, an environmental consultancy in Santa Cruz, Calif.