The Obama administration announced Friday that it would allow exploration for oil and gas off some portions of the Atlantic Coast using sonic testing devices that environmentalists say harm marine life.

The Interior Department’s Bureau of Ocean Energy Management gave the OK for seismic airgun testing, which are boat-towed cannons that shoot sonar blasts off the ocean floor to scan for oil-and-gas deposits, in the mid- and south-Atlantic areas that stretch from the Delaware Bay to just south of Cape Canaveral, Fla. The approval is a prelude to potential offshore drilling there, though that is blocked through 2017 under President Obama‘s five-year offshore drilling plan.