CA - ‘Every square inch is covered in life’: the ageing oil rigs that became marine oases
Built decades ago, California’s offshore oil platforms are home to a huge diversity of marine life. Now a debate rages over their future
In a recent August afternoon, Ann Scarborough Bull motored out two miles from the coast of Santa Barbara onboard a research vessel called the Danny C. The marine biologist and her colleagues had an unusual destination in their sights: a disused oil platform that loomed ahead like a forgotten skyscraper reaching up from the horizon.
The team wasn’t interested in the platform itself, but what lurked beneath. When they reached the ageing structure, named Holly, they lowered a car-sized remote- controlled vehicle under the waves.
There, they saw hundreds of thousands of juvenile rockfish finding shelter amid the hulking metal structure, alongside waving white anemones, clusters of mussels, and silver jack mackerel.
The seasoned marine biologists have been observing this remarkable spectacle for years. Holly, which was put out of use in 2015, is one of 27 oil rigs built off the coast of California decades ago that have become hotbeds of biological activity.
While not natural structures, their platforms have been embedded into the muddy seabed long enough to become part of the ocean environment, providing a home for creatures like mussels and barnacles, which in turn attract larger fish and sea lions that find safety and food there.
After two and a half decades of studying the rigs, Bull says it’s clear to her: “These places are extremely productive, both for commercial and recreational fisheries and for invertebrates.”
Now, as California and the US shift away from offshore drilling and toward greener energy, a debate is mounting over their future. On one side are those who argue disused rigs are an environmental blight and should be removed entirely. On the other side are people, many of them scientists, who say we should embrace these accidental oases and that removing the structures is morally wrong. In other parts of the world, oil rigs have successfully become artificial reefs, in a policy known as rigs to reefs.
For Milton Love, a scientist at the University of California, Santa Barbara, who was on the boat with Bull, it’s a matter of ethics. He first encountered the rigs as an undergraduate student in the late 1960s when he was working as a commercial fisherman and collected fish off the rigs for a public aquarium, just as the platforms started to be installed. “There were a lot of fish,” he says. “That stuck in my mind.”
When he returned to the platforms as a professor years later, Love was initially surprised to find highly diverse communities of fish at each rig. Sites closer to shore had more surfperch, while rigs further out had more ocean fish. He also started to feel uneasy about how the creatures were being discussed. “It kind of crept up on me at some point that removing these things is immoral.”
The fish don’t know they are complicit in a fossil fuel infrastructure that is causing a climate crisis – they just see a hard structure and invertebrates attached to it, and a place to hide.
Bull agrees. “If you take away habitat, then there’s no going back,”she says. “You would never allow the willful destruction of a kelp bed, or of a rocky reef, even though rigs have similar biodiversity.”
An ecosystem emerges
Life tends to find a way, as they say – especially in the ocean.
Drop a tire off a boat on the coast, Love says, and within a month there will be a species like the brown rockfish living in it, darting in and out of the rubber.
The same is true of the rigs. California’s oil rigs were built between 1967 and 1989, and many are now nearing the end of their fossil fuel lives – of the 27 that were built, only 15 are still pumping.
Once the metal structures were installed in the sea bed, they were probably populated quickly by tiny plankton floating around in search of something to hold on to. Then a succession of creatures joined them: barnacles first, which got crowded out by mussels. Within months, fish were living in the rig structures – the lattice metal is an ideal structure to hide in, better than sand, where they are completely exposed to predation.
Within a year or two, an entire ecosystem sprung up. “Nature does abhor a vacuum,” Love says, “which is the reason that on a platform, every square inch is covered in life.”
