The ecological risks of drilling for oil off the Georgia coast are huge, and the potential economic payoff small, according to environmental groups and scientists who study the marine environment.

The federal government did sell leases for drilling rights off the Georgia coast in the 1970s, but explorations then showed “limited” potential for oil production, somewhat better for gas, said Clark Alexander, director of the Skidaway Institute of Oceanography and a geological oceanographer.

“But our experiences with offshore oil wells in the Gulf of Mexico show that there is always risk,” he said.

One estimate suggests that there could be reserves of about 400 million barrels of oil beneath the ocean floor off the Georgia coastline, said Alexander.

According to the U.S. Energy Information Administration, the United States uses about 19.6 million barrels of oil a day, so those Georgia reserves would only satiate the American appetite for about 20 days.

A couple of factors heighten the risk for Georgia waters, said Samantha Joye, a University of Georgia marine scientist who’s extensively studied the oceanic effects of oil spills in the Gulf of Mexico, particularly the 2010 Deepwater Horizon spill in the Gulf of Mexico

One is the history of hurricanes and other major storms in the region. Storms often track across the area proposed for drilling, which makes it “an exceedingly dangerous area for oil and gas production,” she said.

An example of that risk is the Taylor Energy drilling platform in the Gulf of Mexico, she said. Sunk by Hurricane Ivan in 2004, that rig continues to leak oil, and is expected to keep on spilling for many more years.

Another risk is that sediments in the South Atlantic Bight, the area proposed for exploration, are methane-rich, Joye said. In that environment, oil exploration is more dangerous and challenging; it’s one of the reasons why the Deepwater Horizon spill was so damaging.

Major spills like Deepwater Horizon don’t happen every day, but when they do, the damage can be enormous and last for many years.