2022. július 26., kedd

Are offshore oil rigs successful artificial reefs?

You’ve probably seen hulking offshore oil rigs in places like the Pacific Ocean or the Gulf of Mexico. But from the shore, it’s hard to see how truly ginormous some of these oil platforms are. As much of the world moves toward green energy, more oil rigs are decommissioned — which means a huge removal process with many of the behemoths winding up in landfills. But some marine experts suggest we should leave at least part of the rigs where they stand. Many fish and other sea creatures have taken a liking to oil rigs, adopting them as artificial reefs. There are both pros and cons to this idea.

One of many oil rigs in the ocean

How many rigs are there?

It’s hard to get a handle on how many offshore rigs there are, as figures vary widely. They range up to about 12,000 offshore oil and gas platforms worldwide, according to the BBC. Not all of those are active. Some are fixed, others floating.

Related: Artificial coral reefs help marine life and biodiversity

The biggest is the Berkut oil rig near the island of Sakhalin, north of Japan and east of the Russian mainland. Berkut weighs about 220,000 tons and was a beast to get into place. Perdido, in the Gulf of Mexico, is the world’s second-biggest oil and gas platform. It took 12,500 experts to create this thing, which has a hull as tall as the Eiffel tower.

Rigs as reefs

All over the world, fish, barnacles and other denizens of the deep have embraced these unsightly oil structures. “We also see many more porpoises around oil rigs than in the surrounding sea,” said senior researcher Jonas Teilmann from Aarhus University, as reported by JStor Daily. “It’s easy to understand why the porpoises enjoy the area. One can’t throw a fish hook without catching one of the many cod around the legs of the oil rig.”

Ever since the 1940s, oil companies have been planting equipment in oceans and fish have been making it their own. These platform ecosystems can become almost as complex as those around real reefs. Stuff that kills off naturally occurring coral reefs — poor water quality, climate change, pollution, overfishing, coastal development — doesn’t faze oil infrastructure. Plus, rigs serve as safe nurseries for juveniles. Off the southern California coast, rigs are responsible for extremely productive fisheries.

The Gulf of Mexico has more than 500 decommissioned oil rigs that serve as faux reefs. But California is still up in the air about it. The state passed a rigs-to-reef bill in 2010. Under this policy, companies could technically leave at least some of the oil structures in place to provide fish habitats, a practice called “reefing.” The state currently has 27 platforms offshore, ranging from thirty to over sixty years old. But reefing is still so controversial that the state hasn’t yet implemented the rigs-to-reefs idea.

A coral reef with bustling fish

Decommissioning oil rigs

Decommissioning platforms usually involve removing the structure and capping wells in the seafloor. Explosives and divers with very strong saws are necessary to detach the structure from its base. Some of the materials can be recycled but most end up in landfills, as do the attached sea life.

“The smell was beyond anything,” recalled a witness when one of these structures was removed from off the California coast in the 1990s, as reported in Hakai Magazine. “You gotta bury it quick.” As for completely removing the 27 California oil platforms, it could cost a billion dollars or more.

Partial removal is another option. This would mean removing about 85 feet of a platform. This then leaves most of the faux reef intact. But some experts want the entire platform to remain, so that sea lions can rest and nest, and mussels and other clingy types can remain attached. Leaving them intact also makes them easier for passing ships to spot, helping to avoid a Titanic-type mishap.

An oil rig from afar at dusk

Pros of leaving oil rigs in the ocean

Humans have already messed up the oceans and stressed marine animals with pollution, overfishing and habitat encroachment. If the fish have made themselves at home in the rigs, maybe we should leave the rigs and the sea critters alone.  The other major benefit of leaving the rigs where they are is avoiding the carbon-intensive process of dismantling these giant things. And we might need new landfills to be able to fit this amount of waste.

Or are rigs just trash?

Critics of the rigs-to-reef idea also have valid points. Will oil corporations use it as an excuse to legally dump their industrial trash in the sea? Will creating reefs where there weren’t any before attract invasive species that will change the ecosystem?

There’s also the issue of who will be responsible for maintenance. Five states that border the Gulf of Mexico — Alabama, Florida, Louisiana, Mississippi and Texas — participate in the National Artificial Reef Plan. Since 1984, more than 500 platforms in the Gulf of Mexico have been reefed. In Texas, platform operators contribute half of their estimated dollars saved to the reef program. The platform’s title and liability are then transferred to the state. But will there be unforeseen complications, with the state being left on the hook for mega dollars? Also, not all rigs make good reefs. Between 1984 and 2016, companies reefed only about 11% of their decommissioned Gulf platforms. The rest were dismantled and towed back to land.

Public perception is a big stumbling block. Lots of people feel that, on principle, giant corporations should be responsible for restoring the sea floor as much as possible to its pre-rig conditions.

Part of a coral reef beside a school of fish

Minimizing harm

The biggest reason to leave the rigs alone is to not kill their residents. Hundreds of millions of tiny little sea creatures depend on the faux reefs, including lots of them that are living on the steel legs of rigs. As Milton Love, a marine biologist at the University of California, Santa Barbara told Hakai Magazine, “If you remove the platform, you’re killing them all. I just don’t think that’s moral. Why are you killing them because they had the misfortune of landing on a piece of steel rather than a rock?”

Via Marine Insight, Hakai Magazine, JStor Daily and Bureau of Safety and Environmental Enforcement

Images via Pexels and Pixabay



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