Study outlines science behind rig-to-reef efforts

Researchers from the University of California, Santa Barbara (UC Santa Barbara) have outlined a study into the science behind transitioning old oil rigs into permanent reefs, Phys.org reports.

The group of researchers published an extensive study into the history, ecology and pragmatics of rigs-to-reefs projects in the academic journal Ocean and Coastal Management.

In addition to academic insights into the transitionary efforts, the scientists hope that the study will inform Californian residents and policy makers as they decide what to do with platforms due for retirement off the coast.

“California citizens are going to have to make decisions about the continued existence of vast marine life under the platforms, and they should be informed decisions,” said Ann Scarborough Bull, UC Santa Barbara's Marine Science Institute (MSI) researcher and lead author of the paper.

According to the report, there is little doubt that the risks of oil spills has had a negative impact on the environment. Even when the risk is minimised, the consequences of an accident are still high.

“Oil spills are terrible events, and if you put in a platform and you drill and produce oil, you always have some level of risk,” said Scarborough Bull.

Despite the cons of potential oil leakage, the complex structure of the oil rigs creates a three-dimensional reef for animals to colonise and live near. The open construct also allows currents to pass through, bringing nutrients.

“Platforms off of California, as far as fish were concerned, were the most productive habitats in the world,” said Milton Love, MSI researcher.

“More productive than coral reefs, more productive than Chesapeake Bay. Now does that mean that they are truly the most productive? Well, we don't know. But based on the world literature at that time, they were the most productive habitat.”

According to the study, perspectives on rigs-to-reefs efforts vary across country and ideology. For instance, the EU currently follows a preservationist policy in which all decommissioned platforms in the EU must be removed completely.

Meanwhile, reefing old platforms is now routine in the Gulf of Mexico.

As of 2016, over 11% of decommissioned platforms in the US portion of the gulf were transitioned into permanent reefs, Scarborough Bull explains. The region currently has over 500 rig-reefs, not including those that are still part of active platforms.

The price structure surrounding the removal of oil platforms is staggering, the report states. An estimate for removing all platforms off the Californian coast totalled $8 billion (€7 billion), according to Scarborough Bull.

Converting the platforms to permanent reefs requires a structure free of any hydrocarbons or other hazardous materials described in any federal, state or local law, ordinance, rule, regulation, order, decree or requirement. Despite this, the report claims that reefing is still substantially lower in cost in comparison to removal.

“Decisions are going to have to be made about more and more of these structures,” said Love.

“We want everyone to have the same facts as they go into the process so decisions can be made on a rational basis.”