Oil and gas companies want to blast sound pulses 100,000 times more intense than a jet engine to the ocean floor, in hopes of finding fossil fuels off Brevard County and other southeastern American waters.

But environmentalists say the sonic blasts could injure and possibly kill an estimated 138,500 dolphins and whales, and put thousands of tourism and fishing jobs at risk.

A report released Tuesday by the nonprofit group Oceana highlighted federal estimates of wildlife and economic impacts from oil and gas exploration along the Atlantic Outer Continental Shelf.

According to the report, the seismic airguns would put at risk more than $15 billion in economic activity and 400,000 tourism, recreation and fishing jobs in Florida.

“Imagine a rocket being launched out of your living room every 10 seconds, 24 hours a day, for days to weeks at a time,” said Matthew Huelsenbeck, report author and marine scientist at Oceana. “You could go deaf or be forced to move. That’s what it’s like for sea life that is subjected to seismic testing, but unlike in people, a deaf whale is a dead whale.”

The federal Bureau of Ocean Energy Management is considering allowing seismic surveys from Cape Canaveral to Delaware in federal waters, from three to 350 nautical miles out to sea. But the geological surveys and impacts could cross into state waters closer to shore as well. A decision on the tests is expected in October.

Survey ships would tow arrays of the seismic airguns, which produce compressed air bubbles under extreme pressure to create sound.

Hydrophones towed near the surface record the sound that bounces back from the ocean bottom to reveal a 3-D image of bottom formations that may hint at oil or gas deposits.

But any resulting hearing loss in whales and dolphins could harm the mammals’ ability to navigate, feed and care for their young. The sounds also can disturb breeding and feeding and inhibit marine mammals’ ability to communicate with one another.

“Airgun blasts threaten marine life of all sizes from tiny fish eggs to large whales, and people too,” Huelsenbeck said. “730,000 East Coast jobs depend on a healthy ocean in the region that could be harmed by airguns or drilling. But we don’t have to turn the Atlantic into a blast zone.”

A draft federal environmental study released last year includes several alternatives for ways to avoid harming whales, sea turtles and other wildlife. Proposals include closing areas up to about six nautical miles offshore to seismic surveying during the main sea turtle nesting season — May 1 to Oct. 31. An additional area 20 nautical miles out could be off-limits for the sound surveying during right whale migration — Nov. 15 to April 15.

Most research revolves around sound impacts on marine mammals. The impacts on sea turtles are less clear. Sea turtles don’t have ear drums or external ears, but their auditory sense is adapted to vibrations in the water.

Oceana wants the government to phase out the use of airguns in federal waters and to do more to promote renewable energy such as wind instead of oil.

“In the long-run, it’s only going to keep us more addicted to fossil fuels,” Huelsenbeck said of more oil exploration in the Atlantic.