Though the Obama administration in March put a halt on drilling for oil and gas in Atlantic, the dolphins and whales inhabiting the waters are still at risk, says one ocean conservation group, as proposed seismic airgun blasting to look for reserves of the fossil fuels would leave the marine mammals "profoundly impacted."

The scale of the threat they face was laid bare on Wednesday with a pair of new maps released by by Oceana. Based on extensive research from Duke University's Marine Geospatial Ecology Lab, the maps—one for bottlenose dolphins and the other for endangered humpback, fin, and sperm whales—show the overlapping areas of the proposed blasting in the area stretching from Delaware to Florida and the density of the whales and dolphins in those waters over a 12-month period.

"These animated maps clearly show that marine life, including dolphins and whales, would be profoundly impacted by the proposed seismic blasting," stated Dr. Ingrid Biedron, marine scientist at Oceana.

With this kind of exploration, Oceana states, blasts are "repeated every ten seconds, 24 hours a day, for days to weeks at a time." The impacts of such blasting, as the group has explained, can include temporary or permanent hearing loss, and, because whales and dolphins "rely on their hearing to find food, communicate, and reproduce, being able to hear is a life or death matter." The Center for Biological Diversity has also described the blasting as "actually a blunt-force weapon," as it emits "the loudest human sounds in the ocean, short of those made by explosives."

By the government's own estimates, Oceana adds, up to 138,000 whales and dolphins could be harmed, and millions more disturbed, by the blasting.

"The noise from these blasts is so loud that it can be heard up to 2,500 miles from the source, which is approximately the distance from Washington, D.C. to Las Vegas," Biedron added.

According to Claire Douglass, campaign director at Oceana, the "maps confirm what we've long feared, that dolphins and whales along the East Coast are at risk from dangerous seismic airgun blasting for oil and gas."

"Hearing that whales and dolphins could be injured is one thing, but seeing the scale of the threat is another. President Obama should stop seismic airgun blasting and protect our coast," Douglass said.

Twenty-eight marine biologists have also urged Obama to call off the blasting, expressing specific concern about its impacts on the endangered North Atlantic right whale. They wrote in a letter to Obama in April that the blasting "may well represent a tipping point for the survival of this endangered whale, contributing significantly to a decline towards extinction."

Similarly, 75 marine scientists sent a letter (pdf) last year to Obama to express their concern over seismic blasting in the waters, writing, "Opening the U.S. East Coast to seismic airgun exploration poses an unacceptable risk of serious harm to marine life at the species and population levels, the full extent of which will not be understood until long after the harm occurs."

It's not just scientists sounding alarm. On top of environmental advocacy organizations, local municipalities and business intersts have vocalized their opposition, and concerns are also being expressed by some lawmakers. Last month, as Facing South writes, "a bipartisan group of 69 state legislators from North Carolina, South Carolina and Georgia sent a letter to Interior Secretary Sally Jewell citing the multiple threats seismic testing presents and asking the administration to block all requested permits."