More than 12,000 offshore oil rigs are still running today, supplying the world with crude oil and natural gas. Many are nearing the end of their lifespan, and the question remains about what to do with these structures once they can no longer pump oil. Four Nature contributors offered a carefully researched scientific approach: make them into coral reefs.
Most rigs are stationed between the Gulf of Mexico, the Asia-Pacific region, and the North Sea, with 1,500 to 3,000 per region nearly 30 years old. The problem with decommissioning them is the labor, time, and money needed to do so. They have to be stripped apart piece by piece, but often, oil companies abandon them in the ocean. Some are toppled and left to rot on the ocean floor.
There is a lot of support for toppling because of the artificial reef building it will cause. A United States Department of the Interior report says ample work is being done to convert decommissioned rigs into reefs. As of December 2021, 573 platforms have been reefed in the Gulf of Mexico.
The U.S. government has been doing this since 1984, focusing on the economic and social impact artificial reefs have on coastal areas.
According to the Bureau of Safety and Environmental Enforcement (BSSE), an eight-leg platform can house 12,000 to 14,000 fish, while a four-leg structure can create two to three acres of marine habitat.
That’s just the pylons connected to the Outer Continental Shelf.
Photo Courtesy U.S. Department of the Interior
Another program from the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Department of Commerce, the National Artificial Reef Plan, says artificial reefs allow American marine life to thrive while helping the fishing industry find less-congested spots.
The 61-page document, produced in 2007, outlines the social and economic benefits of reefing but champions caution and consideration of environmental factors. It says that reefs can help slow the erosion of beaches, create natural filters for the ocean, and create better recreational fishing.
Reefing oil rigs isn’t a clear-cut process. Several challenges emerge, especially pushback from environmentalists who don’t think it is healthy for sea life.
There is a lack of global evidence about the practice’s benefits, with most academic studies drawing theories from American structures in the Gulf or off the coast of California.
In the 1990s, public opposition to the disposal of the Brent Spar in the North Sea led to strict legislation in the northeast Atlantic. There are calls for a reconsideration of international transatlantic cooperation concerning oil rig decommissioning and reefing.
The Nature contributors collected the opinions of 39 influential figures across four continents about reefing rigs. The consensus was that there are still plenty of risks of chemical contamination. There could be disruptive marine ecology, but there are benefits, such as commercially valuable fish gathering near rig sites. Rockfish love to populate near platform pylons, and Mussels also take up residence.
Photo Courtesy Texas Parks & Wildlife Dept.
Reefing rigs may also help governments achieve climate-action goals. The Nature panel found that this practice would help world leaders meet nearly 37 global environmental targets in three international treaties.
However, not every ecosystem will respond the same to artificial reefs. The North Sea marine life is not the same as that of the Gulf of California or the coast of Thailand. Reefing could significantly impact these countries’ marine ecosystems, but it is not a clear-cut, one-size-fits-all strategy.
Marine biologists from the University of California-Santa Barbara support reefing the Holly, a disused platform looming off the So-Cal beachfront. Underwater videos captured rockfish, silver jack mackerel, mussels, barnacles, and white anemones taking up shelter by pylons.
The Guardian reported that Holly has been out of use since 2015. It’s one of 27 oil rigs remaining off the coast of California, and 18 have become marine biology hubs since being abandoned. Sea lions and seals use these grounds to feed. There are identifiable characteristics that artificial reefing could benefit the California coast, but there is still pushback because of the uncertain environmental risks.
Still, the money to break down an oil platform is significant, and reefing these structures can save millions of dollars a year. According to the BSSE, reefing an outdated rig costs less than half the price. It also helps restore the world’s coral, which has been immensely damaged by ocean warming and acidification. While the process still needs to be researched thoroughly, it may be a solution to provide marine ecosystem restoration.
