Deepwater Horizon fallout still being studied 15 years later | Business News

Out on the edge of Louisiana’s coast, a set of giant plant pots stand as reminders of the worst-ever oil spill of its kind. But you couldn’t tell just by looking at them.

The rows of containers sit under a wood frame and netting. Inside grows the same cordgrass that carpets the marshes stretching out within eyesight of this spot, in the tiny community of Cocodrie.

It’s all part of an elaborate experiment continuing to reveal some effects of the 2010 BP Deepwater Horizon oil spill.

“There are a lot of lessons learned that will come from this,” said Brian Roberts, referencing the range of research that the spill prompted. He conceived the cordgrass experiment with colleagues.

“It hopefully will help us better prepare in the event that something else happens,” added Roberts, the executive director of the Louisiana Universities Marine Consortium, as he walked elevated planks among the fiberglass containers.

April 20 marks the 15th anniversary of the blowout and subsequent spill at the Macondo well off the Mississippi River’s mouth in the Gulf. The Deepwater Horizon rig, owned by Transocean and operated by BP, blew up, leaving 11 crew members dead.

Oil gushed into the Gulf for 87 days as attempts to cap it failed. In the end, an estimated 4.9 million barrels of crude oil spilled, much of it reaching the shore across the Gulf Coast.

It was the biggest waterborne oil spill in history.

In total, oil reached more than 1,300 miles of Gulf shoreline, with Louisiana hardest-hit. Over 200 miles of marsh saw moderate-to-heavy amounts of oil.

The cause of the blowout involved a series of failures. They ranged from poor cementing and well-control procedures to the failure of a blowout preventer, among other factors.

The subsequent fallout was immense, as were the legal ramifications, though the tragedy also led to some positive outcomes. In one notable example, Louisiana has used billions in fines and settlements to carry out large-scale coastal restoration projects in the years since.

But a lesser-known example involved funding for scientific research on oil spills and surrounding ecosystems. BP agreed to grant $500 million over a decade to pay for such research, overseen by an independent body.

The money was granted with no strings attached. It allowed the independent body, the Gulf of Mexico Research Initiative, to finance research as it saw fit, said Chuck Wilson, a longtime LSU professor who served as the initiative’s chief scientific officer.

A hefty list of research benefited, eventually uncovering findings on the oil’s severe effects on the marsh, dolphins and species that live deep underwater, among many others, Wilson said.

‘A huge addition’

As one striking example, a researcher found shortly after the spill that the number of small fish, zooplankton and other invertebrates in deep waters known as the mesopelagic zone dropped off by around 70%, said Wilson. Those species form an important part of the food chain.

There were also slivers of good news. Wilson notes that the Gulf was accustomed to both natural and accidental oil releases over many years, with lots of bacteria in the water adept at digesting it, and that happened to a large degree.

The 10-year run of the research initiative has now expired, but some of the work continues using other grants.

“You can imagine being able to give out $50 million a year for a 10-year period was a huge addition to available research dollars coming to the Gulf of Mexico,” Wilson said.

Roberts and LUMCON were among those beneficiaries, and their findings on the oil’s effects on marsh have proved far-reaching.

The complex plan they developed involved mimicking natural marsh and tides as much as possible, and that’s where the giant plant pots came into play — a mesocosm experiment, in scientist-speak.

The 12 pots are five feet tall. Each includes a layer of marsh removed from the area — over 1,600 five-gallon buckets of it in total, taken intact by hand. They also hold a total of 50 tons of mud from marshes.

To imitate tidal movement, the pots are connected to tanks holding water from a nearby bayou, delivered at intervals to the pots. It is designed in such a way to mimic a rising and falling tide of up to two feet.

Eventually, in 2019, about a year and a half after the marsh planting was complete, it was time to spread oil inside the pots. First, it had to be weathered to replicate the state the Deepwater Horizon oil was in when it reached the marsh. Then it had to be spread among the pots at different levels. Some received none, while others received high amounts.

Roberts and others dressed in protective gear in the hot summer sun to do the job — not an easy proposition. He said he sweated out significant weight in the process.

That only begins to describe it all.

‘The pieces play together’

Aside from tests to see how the marsh handled the oil, scientists ran other experiments to examine fish behavior in the same circumstances, including survival rates and what they did in reaction to the contaminants.

As for the marsh itself, the level of oil made a big difference, and areas with the heaviest amounts saw cascading effects that speeded erosion, Roberts explained.

In areas heavily covered, where oil snaked down to the roots, the dying plants no longer held sediment together that maintained the structure of the marsh. That was an especially important finding for Louisiana’s coast, which is already losing land at a rapid clip.

“So what you see is oiled areas eroded much faster than the other areas of the coast,” said Roberts. “Once that’s gone, there is no recovery, right? That’s the extreme.”

As time passed, Roberts and other scientists began to see recovery in the interior of the marshes, but not so much on the edges, where the heaviest oiling occurred — as happened with the spill. That can have effects further along the food chain, from algae and invertebrates to, gradually, larger animals.

“There’s a cascade here in terms of time delays and some things responding,” he said. “That’s one of the things that we really had discovered. That it’s a lot more complex in terms of, if you look at one organism or group in isolation, you may get a different story than if you look at how all the pieces play together.”

The BP funding has stopped, but the pots live on and are still being monitored, though not as intensely as before. Roberts said he’d like to find more research funding for the experiment for new types of testing.

Wilson from GOMRI said the cumulative knowledge built up through the BP-related research will better serve responders and scientists when the next spill inevitably occurs.

“It was a huge mix of different projects and people,” he said.