(CBS News) Thirty-eight miles off the Louisiana coast, a platform stopped producing oil more than a decade ago.
"This rig is scheduled to come out of the water this year," says John Hoffman, the CEO of Black Elk Energy, which owns the rig.
Hoffman wants it to stay where it is. To see why, we boarded a mini-submarine to look beneath the surface.
Past the murky shapes of dolphins and sharks, we found an explosion of color and life. One hundred feet down, it's not a coral reef, but an old, unused oil rig. It's like being in a fish tank.
The rig's coral-covered legs attract thousands of sea creatures. It's a magnet for fishermen and known to scuba divers as an underwater Garden of Eden.
Dr. Paul Sammarco is a biologist with the Louisiana Universities Marine Consortium. He says there are hundreds of old oil platforms that look like this, but under federal law, they're required to be removed in the next few years.
"When we put these platforms in, we had no idea they were going to develop into these massive artificial reefs," Sammarco says. "They are more environmentally valuable in the water than they are scrapped out of the water."
Ronnie Anderson, a fourth-generation shrimp fisherman, couldn't disagree more strongly.
"I would like to see it cleaned up," he says.
The Gulf bottom, he says, is littered with old pieces of oil rigs that get caught in his nets. It will only get worse, Anderson says, if dilapidated platforms are allowed to remain as reefs.
Watch: Lionfish devastate reefs, threaten native fish in U.S. coastal waters, below.
While the oil companies say it's all about the environment, Anderson says "it's about saving money."
"If it's going to cost them more money to make rigs to reefs, they're not going to do it," he says. "They're only doing it because it's saving them money. That's the bottom line."
It would cost John Hoffman about $3 million to remove the rig -- money he'd rather put into a trust fund to preserve the reef.
"There's just a wonderful ocean of mystery and intrigue associated with these ecosystems," Hoffman says.