With federal decisions pending on whether to open the South Carolina offshore to seismic testing and possible exploration for oil and natural gas, Congressman Mark Sanford toured a Gulf of Mexico oil operation and offshore rig this week.

The pending decisions are certain to touch off more debate whether the coast is more valuable as a tourism or industry resource, or whether the two can coexist. Sanford, R-S.C., came away impressed, he said. He is holding to his position that any decision on exploration within sight of the coast be left to state government.

"I'd say I'm more open to it than I was before. But the specter of (operations) offshore doesn't fit with the look or feel our tourists know," he said.

Sanford was invited on the tour by Rep. Steve Scalise, R-Louisiana to gauge the problems and preventions put in place in the aftermath of the catastrophic 2010 Deepwater Horizon spill. He said he questioned engineers and oil rig platform workers, and came away convinced that the companies investing in the billion-dollar rig operations were protecting their investments. The Magnolia rig of Conoco-Phillips that he toured was drilling deep into a bottom 5,000 feet below.

"I walked away quite impressed with the professionalism on the rig and the standards," he said. "The engineering is mind-boggling. The scale is monumental. How in the world does man create that?"

Sanford's tour came after the federal Bureau of Energy Management recently signed off on a mitigation plan for environmental impacts of seismic testing, a decision that leaves many observers expecting the bureau to give the go-ahead for the testing later this year.

In seismic tests, crews detonate compressed air guns dragged behind ships, creating a series of blasts to read the "echo" beneath the sea floor. The blasts can deafen or injure marine mammals, such as whales or dolphins, that navigate by sonar echoes, and are suspected of injuring other marine life.

The mitigation plan calls for monitoring and stopping operations if animals are discovered nearby. But the measures don't satisfy conservationists who wanted tougher restrictions.

The issue strikes at the heart of Lowcountry life on the ocean. Nine companies have applied for permits to explore for oil and natural gas along all or part of the Southeast coast, if the region is opened to leasing in 2017. Exploration can cost $4 million or more. All the companies want to use seismic blasts and all want to look off South Carolina, even though geology and earlier testing suggest there is little currently exploitable oil or natural gas to be found.

Sanford said he did not object to the testing.

"At least then you have a stronger feel of whether there's any need to explore. It may make it all a moot point," he said.

"He certainly makes a good point," said Katie Zimmerman, Coastal Conservation League program director. "You want to explore before you drill. But the (environmental) effects of seismic testing are a huge problem. It's not a minor annoyance to these species. If they're not killed, they're deafened and can't survive."

The prospect of offshore drilling presents a "very dangerous scenario," she said. Pollution from the Deepwater Horizon spill persists in the Gulf. "Even if you're not concerned for the marine species, most people are eating things that come out of the ocean. We're swimming in it. We need to have a serious, serious discussion about it. Certainly we need to be really careful going forward."

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