An Unexpected Silver Lining for Decommissioned Offshore Oil and Gas Platforms

By Lily Zhao

In the 1990s the decommissioning of Brent Spar, an offshore oil storage platform, sparked public controversy. Yesterday afternoon, Professor Tom Leschine, an expert in risk management and marine policy, told me the story of this 137-meter-tall platform – one many of us graduate students are a little too young to remember. In 1995, the United Kingdom granted Shell U.K. permission to dispose of Brent Spar off the northwest coast of Scotland. The global campaigning organization Greenpeace led protests, claiming highly toxic materials were left in Brent Spar’s holding tanks and that the ocean could not be used as a dumping ground. As a result, Brent Spar in its entirety was eventually taken out of the water, cleaned and recycled into the foundation of a new ferry terminal. However, upon removal, large quantities of coral including a rare species were found growing on its underwater columns. People began to wonder if the base of the structure should have been left in place.

Sea anemones, scallops, mussels and other marine life colonizing the beams of an offshore oil rig in California Copyright Joe Platko


While Brent Spar’s future is no longer up for debate, the controversy surrounding old offshore oil and gas platforms is still very much alive today. Globally, as the productivity of oil rigs decrease, they are decommissioned. Their owners – companies like Shell, BP, and Exxon Mobil – along with regional governments, must decide what to do with the offshore structures, some of which have been found to be extraordinarily productive fish habitat. Currently, there is no international standard for decommissioning unproductive oil rigs. Most are completely removed from the sea. However, one option permitted in Louisiana, Texas, Mississippi, and California, is to remove the upper portion of the platform, but leave the structure below 80ft intact. This partial decommissioning process is commonly referred to as “rigs-to-reef” and allows the rig structure to continue to serve as habitat for coral and fish assemblages.

On one hand, some members of society are opposed to the partial decommissioning of oil rigs, claiming that offshore drilling has done enough damage to the environment and that platforms should be removed entirely when the rigs are decommissioned. Members of the Sierra Club California Chapter agree, arguing that allowing oil rigs to remain in place is akin to leaving trash in the ocean. Other non-profits such as the Environmental Defense Center oppose rigs-to-reef initiatives in California in part because leaving rigs in place saves oil companies from the cost of full removal. The potential for these platforms to be hosts for invasive species, cause pollution through toxic materials, or be safety hazards for boaters are also cited as potential concerns.

Another camp, however, has noticed the unparalleled biological productivity that has arisen naturally in these once unnatural environments. Environmental organizations such as the Nature Conservancy and Mission Blue favor rigs-to-reefs initiatives when they can be used to keep coral habitats intact.

Enter Emily Callahan and Amber Jackson. After graduating with master’s degrees from Scripps Institution of Oceanography at the University of California San Diego, the duo noticed a need for in depth biological assessments to address the complex issues associated with offshore structures. In response, Callahan and Jackson created a unique consulting company, called Blue Latitudes, that offers these services to governments and private companies that are making choices concerning offshore oil rig decommissioning.

Emily Callahan and Amber Jackson, co-founders of Blue Latitudes. Copyright Gage Hingeley


These two pioneering women have used this venture to help answer some new and puzzling questions in conservation science, such as “is it more ecologically damaging to remove them (the oil rigs) or leave them in place?”

Conservationists and offshore oil rigs may seem like strange bedfellows. However, in the face of climate change and other anthropogenic pressures impacting the ocean, artificial structures could provide critical habitat as part of marine reserve networks. Callahan and Jackson are the first to admit not every rig is a good candidate for the rigs-to-reef process and are for rigs-to-reef on a case by case basis. Through their partnership with Dr. Sylvia Earle’s nonprofit Mission Blue, Callahan and Jackson provide public outreach and education on rigs being a habitat for marine life. Through the advocacy component of their work, they “want to encourage people to think outside the box when it comes to ocean conservation,” said Callahan.

Their work is challenging, unique, and necessary, in an era where the use of fossil-fuels themselves is becoming increasingly morally questionable. Indeed, we often leave our planet with permanent and undeniably negative bruises that are likely to persist for generations. But in some scenarios, nature has a way of surprising us with its capacity to adapt. Emily and Amber call the ability of these rigs to serve as essential marine habitat “the silver lining to oil and gas development”. Beyond the particularities of oil rigs, they have found their work with the rigs-to-reef initiative to be at the center of a much larger, complex question that begs our attention- “Should we artificially modify our environment, and if so, what are the limits to that?” asks Amber.

For more information, check out

Amber Jackson and Emily Callahan’s rigs-to-reef website

or the peer-reviewed publications:

Claisse, J. T. et al. Oil platforms off California are among the most productive marine fish habitats globally. PNAS 111, 15462–15467 (2014).

Friedlander, A. M., Ballesteros, E., Fay, M. & Sala, E. Marine Communities on Oil Platforms in Gabon, West Africa: High Biodiversity Oases in a Low Biodiversity Environment. PLOS ONE 9, e103709 (2014).