CHARLOTTE HARBOR, Fla. -- A rusting oil rig perched on the muddy bottom of the Gulf of Mexico, notorious for its vast "dead zone" off the Mississippi Delta, might seem an unlikely setting for a thriving ecosystem.
But that is exactly what Paul Sammarco has found on more than a dozen of the 4,000-plus drilling platforms that dot the Gulf. Sammarco, a marine biologist at the Louisiana Universities Marine Consortium, has discovered that the rigs have spawned lush marine habitats that are home to a profusion of rare corals and 10,000 to 30,000 fish each.
The results of his research, which he will publish later this spring in the journal Marine Biology, have thrown a surprising new wrinkle into an ongoing debate on how best to dispose of the thousands of old rigs due to be abandoned as oil and gas production winds down. His work has also raised questions about the "Rigs to Reefs" program under which states bordering the Gulf have been turning old rigs into artificial reefs designed to sustain fish, sponges and other marine life.
Most Gulf oil fields in depths of less than 600 feet will become unproductive in the next 10 to 15 years, industry sources say. The platforms will be abandoned at the rate of 150 to 200 a year, and federal law requires that they be removed within a year after the end of exploration and production.
"There's a problem with that in the Gulf of Mexico," Sammarco said. "Most of the bottom is mud, so oil rigs provide the only hard bottom on which marine animals can settle and hunt for food. Once a rig is moved in any way, an entire ecosystem is gone."
The fate of the oil rigs has also attracted the attention of fishermen such as Dan Leonard, who raises clams at his Bull Bay Clam Farm, near here. He thinks the platforms could be the foundation for an offshore ocean farming business.
Leonard described his vision recently as he pushed the throttle of his boat "Scow" to full power, with the vessel skimming the waters toward a four-acre area of sea bottom he had seeded six months ago with tiny clams.
A biting wind blew across the Gulf of Mexico, throwing up waves carrying red tide, a bloom of toxic algae. He has leased the sea-bottom tract from the state of Florida for years, but he has not been able to harvest clams this spring because of the red tide.
He pointed to the dead and dying mangrove trees lying like fallen soldiers along the shore. Hard hit by several hurricanes, the ailing mangroves, like the red tide, are ominous signs, Leonard believes.
"If it's not hurricane damage doing us in, it's red tides, or it's out-of-control development all along the coast. We need to move offshore and try this away from where our farms can be so easily destroyed," he said.
"Sitting in the Gulf are hundreds of oil rigs no longer being used, so why not take advantage of them?"
Leonard is not alone in thinking that the Gulf's drilling platforms have more to offer.
For differing reasons, aquaculture farmers, biotechnology companies, fishermen, scientists and oil executives agree that a new life could await the rigs once they are no longer needed for drilling.
But in a bit of environmental irony, the Outer Continental Shelf Lands Act, which requires the removal of obsolete oil rigs, stands in the way of these proposed uses and threatens the surprising marine habitats.