Concrete Progress is an ongoing series of columns by Peter Brewitt devoted to exploring America’s infrastructure. It is part of Orion’s Reimagining Infrastructure project. Photographs courtesy of NOAA Fisheries West Coast and Mark Edley.

It’s a long drive down the coast from Santa Cruz to LA, but the heart-lifting sweep of Pacific Ocean away to the right makes the miles roll by as easily as the waves. The coast is only lightly developed for long stretches—rugged cliffs lend themselves to BMW ads but not to towns—and the ocean-scape is only broken by sea stacks, foam, and the occasional gray whale.

But when you approach Santa Barbara, oil rigs* jut from the water like pimples on an eighth-grader. This is where our energy infrastructure begins, with enormous steel islands drilling almost a mile under the seabed. Sometimes, as you surely know, they rupture: in 1969, one of them leaked three or four million gallons of crude oil onto beaches and helped kickstart the environmental movement. There are twenty-seven such rigs bobbing off the California coast—operated by Chevron, Exxon, and smaller firms—and while they’re mostly well-maintained, the question remains: when the well goes dry, what should we do with the gear? In recent years, a movement has begun in coastal states from the Gulf of Mexico to the Pacific Ocean to turn these oil suckers into artificial reefs.

While it would be better for the environment not to drill at all, that’s not the question here. This stuff has already been built. Now that it’s getting old, is it better to blow the platforms off of their anchors, tow the metal out, and scrap it someplace? Or is it better to simply let nature assert its claim?

Scuba divers have known for years that industrial wreckage turns into habitat—many of the world’s most popular dive sites are shipwrecks. But oil rigs, the floating symbols of environmental destruction? You might be skeptical of this (you should be; I was) and wonder just how good a big, dead oil platform can be for marine ecology. Well, after some research, I’d say that it’s a pretty good thing.

Here’s how it goes: states work with oil companies to drain oil away from old platforms, remove their upper portions, and tow them away. The oil companies are happy to do this—it is overwhelmingly cheaper than disposing of the whole thing—and they are responsible for any leaks from the old well. State programs then shuttle about half the oil companies’ savings into marine conservation and research programs (in Texas, for example, the money goes to the state’s Parks and Wildlife service). The structure goes on to host invertebrates (many of which have already attached to it during its operational life), exposing very little actual metal to the water. The invertebrates attract fish, including species that are popular for commercial and recreational fishing, and the platform’s extension deep into the water column provides habitat structure in several conditions, including the sunlit waters near the surface. California’s reefs are typically rocks, not coral, so the metal structure is not terribly different from what the fishes there are used to.

But will artificial reefs simply attract fish away from natural habitat instead of increasing overall ecological productivity? I called Peter Raimondi, a marine biologist from University of California Santa Cruz who studied the issue in 2000. He told me that the platforms do, in fact, seem to add to overall productivity. He also emphasized that the impact on regional populations one way or the other is likely to be negligible—the platforms are tiny specks compared to the entire coast. In their specific locations, though, they do create a rich ecological island, and along with some environmental benefits offer an intriguing destination for anglers or anyone who wants to dive in the reliably-frigid Pacific Ocean.

Fortunately, some do—and they are illuminating the platforms’ contributions. Two young scholars from San Diego’s Scripps Institution of Oceanography, Amber Jackson and Emily Callahan (I got much of the above information from their excellent website), run the Rigs to Reefs Exploration Program. The program, which began this spring, gets divers out to see whether marine wildlife actually do thrive on oil platforms. I’ll let them describe what they found at a drill site called Eureka:

A spectacular dive…Eureka boasted an immense and colorful reef. We found ourselves transfixed by the thousands of schooling sardines, tired, but determine[d] Garibaldi defending [their] newly laid clutches of eggs and jacks hustling betwixt the beams. These platforms were not only rich with life, but diver friendly, allowing relatively unrestrained access to their reefs below—some divers even proceeded to harvest enormous scallops the size of tennis balls from her legs.

(Environmental assessments aside, I am in favor of anything that involves free wild scallops.)

This story goes beyond California. The world being what it is, every sea on the planet with oil beneath it has, or will have, rigs out there slurping it up. There are many hundreds of oil rigs in the world’s oceans, and they’ve been colonized by marine wildlife in locations from western Australia to Borneo to the Bering Sea. Tapped-out drilling platforms in the Gulf of Mexico have been providing habitat for decades. California’s oil rigs are expected to last 200 – 300 years as reefs before finally giving way. Just as we’re seeing railways turned to hiking trails, so too can these platforms, after years of drilling, provide habitat long after the oil is gone.

*Note: while these are commonly known as rigs, they are actually oil platforms, with the drilling rig mounted upon them. I use the terms interchangeably.

Peter Brewitt has wondered about infrastructure ever since a flood kept him away from three days of kindergarten. He wrote his doctoral dissertation on dam removal politics at the University of California, Santa Cruz, and will begin an Environmental Studies professorship at Wofford College this fall. In his academic work, he researches the ways people decide to restore and remake their environments.