The Interior Department said Thursday that sonar testing off the Atlantic Coast would not significantly harm aquatic life, a move that serves as a precursor to potential offshore drilling in the region.

The use of seismic airguns -- in which sonar blasts are sent to the ocean floor to detect possible oil and gas deposits in the ocean floor -- has been contested by environmental groups who say it stuns and deafens aquatic life, which eventually leads to their death. But its proponents in the oil and gas industry say the technology has improved in recent decades, limiting marine disruption, and that it's more environmentally friendly than drilling exploratory wells.

The final environmental review from Interior's Bureau of Ocean Energy Management largely agreed with those arguments. While it noted that seismic airgun testing would affect several species, the review said the impact for most would be "minor" or "negligible" -- though it did say fish might face a "moderate" level of disruption.

The review itself does not authorize the use of seismic guns. It does, however, set the table for a potential ruling allowing it.

The Obama administration forbids Atlantic Ocean drilling through 2017. An earlier version of President Obama's five-year offshore drilling plan permitted such activity, but he excluded Atlantic drilling from the plan following the 2010 BP oil spill in the Gulf of Mexico.

Environmental groups saw the review released Thursday as the first step toward allowing Atlantic drilling. They pointed out that parts of the environmental review said seismic airgun testing would affect aquatic life, and urged the administration to prohibit the practice.

"Opening the door to drilling off the Atlantic coast is a poor decision. The government's own assessment has shown that seismic testing will injure or kill thousands of animals. And the risks will only grow if drilling moves forward, threatening coastal economies, sensitive shorelines and our climate," said Athan Manuel, public lands director with the Sierra Club.

The oil and gas industry says seismic airgun testing limits environmental and business risk, and note that no aquatic deaths have been directly attributed to its use. It is looking to the Atlantic Ocean as a potential gusher for jobs and new oil and gas -- the American Petroleum Institute says drilling there would provide 280,000 jobs and add $23.5 billion to the economy each year between 2017 and 2035.

"The Department of the Interior is about to take a critical step impacting American energy production, job creation and energy security in the years ahead," said Erik Milito, director of upstream and industry operations for the group.

But opponents say it would disrupt fisheries and tourism that support 200,000 jobs and brings in $11.8 billion annually, according to ocean conservation group Oceana.

Some Democrats are pressuring the administration to block seismic airgun testing. Nine senators, led by Cory Booker of New Jersey, Sheldon Whitehouse of Rhode Island, and Ed Markey of Massachusetts, wrote Wednesday to Interior Secretary Sally Jewell that the administration should proceed with caution until more is known about the testing's effects on aquatic life.

“There is no reason to rush the [analysis] or permit seismic surveys in the mid- and south Atlantic without considering this new scientific information," they wrote, according to the Houston Chronicle.