Marine populations in the deep waters of the Gulf of Mexico plummeted by roughly 60 percent in the years following the 2010 Deepwater Horizon explosion, with little evidence of recovery, a new study has revealed.
asserted
study → plummet → recovery
In a critical mid-water area of the Gulf where the BP-operated well failed—releasing 134 million gallons of oil—fish numbers fell by 63.5 percent between 2011 and 2015.
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numbers → operate → 2011
According to research published on Monday in the journal PNAS, crustaceans such as shrimp and krill dropped 62 percent, while larger creatures including squid and octopuses declined by 59.7 percent.
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creatures → accord → percent
The findings indicate these marine populations have not come close to recovering.
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populations → indicate → ?
Researchers focused on the ocean’s "twilight zone," an expansive region above the seabed where marine life, including dolphins and whales, feed on smaller creatures.
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life → focus → creatures
Little was known about this massive ecosystem, as it had not been evaluated prior to the 2010 disaster, noted lead study author Tracey Sutton, a biological oceanographer at Nova Southeastern University.
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Sutton → know → University
A 2011 post-spill survey used six sets of nets at varying depths, along with acoustic sonar, to assess sea life between the surface and 5,000 feet deep (1,500 meters).
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survey → use → surface
Returning to the identical location with the same equipment three and a half years later, scientists discovered that marine life had dropped to between one-third and one-quarter of its 2011 levels.
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life → return → levels
"We saw this big decline," Sutton said.
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Sutton → see → decline
So we looked at all of the natural variables we thought could account for it, namely temperature, oxygen supply and food.
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we → look → it
None of those vary with the decline.
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None → vary → decline
The event that did was the oil spill.
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that → do → ?
So we think that’s the most likely cause of the decline.
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that → think → decline
"
Ongoing sampling through 2015 and beyond showed populations remained suppressed, with slight upticks in 2022 and 2023 that proved statistically insignificant and temporary, Sutton explained.
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Sutton → ongoe → 2022
The research team documented the collapse using net catches, acoustic sonar data, and genetic analyses showing reduced genetic diversity from inbreeding.
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team → document → inbreeding
While the initial explosion killed 11 workers and nearly five months of leaking petroleum caused widespread immediate deaths, surviving animals passed absorbed pollutants into their eggs, leaving subsequent generations increasingly compromised, Sutton noted.
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Sutton → kill → generations
BP spokesperson Paul Takahashi said the accident "forever changed" the company: "We have made many changes intended to help prevent an event like this from ever happening again.
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We → say → this
"
Both crude oil and chemical cleanup dispersants caused harm, though in distinct ways, co-author Isabel Romero, a chemical oceanographer at the University of South Carolina, said.
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Romero → cause → Carolina
Oil poses a broader toxic threat, but dispersants broke it into tiny droplets, increasing exposure for organisms living deeper in the water column.
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dispersants → pose → column
Rita Colwell, an environmental microbiologist at the University of Maryland who led a 10-year, $500 million BP-funded research program, noted that future cleanup efforts should avoid chemical dispersants and instead use agents that promote oil-degrading microbes.
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that → lead → microbes
Although an exact direct causal link cannot be definitively proven, Sutton stated that ruling out natural environmental factors leaves the spill as the logical cause.
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ruling → prove → cause
Krill numbers dropped 72 percent, lanternfish fell to one-third of prior levels, and deep-sea dragonfish suffered severe losses.
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dragonfish → drop → losses
"These are foundational species," Sutton said.
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Sutton → say → ?
"They're the things most things eat.
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things → eat → ?
So it's no wonder that we had wholesale changes across the community."
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we → have → community
The findings also highlighted how connected the deep ocean is to the upper layers.
"
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ocean → highlight → layers
One of our biggest findings from the whole thing is how connected the whole oceanic Gulf is from top to bottom because the animals move up and down," Sutton said.
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Sutton → move → bottom
"There are predators at the top that dive deep.
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that → be → top
Lots of things that are deep that come up at night.
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that → come → night
So the system is one very large pulsing system, rather than just a layered system like people might have thought beforehand."
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people → pulse → system
Outside scientists expressed serious concern over the findings.
"
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scientists → express → findings
We know more about space in some ways than we do about the inner ocean.
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we → know → ocean
Because we can’t see these regions, there is a tendency to assume everything is fine, but here we have a clear result showing that something went very wrong," Scripps Institution of Oceanography marine scientist Kaitlin Frasier said in an email.
Frasier, who was not involved in the study, previously authored a 2024 paper showing Gulf whale and dolphin population drops of up to 83 percent.
Dalhousie University marine scientist Boris Worm added: "It’s shocking how a single failure in a drilling rig can have this vast and sustained impact over thousands of square kilometers, with little visible recovery over 13 years after the spill."
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failure → see → spill
He and Colwell emphasized that these long-term impacts should serve as a warning as global debates continue over deep-sea mining and expanded deep-water oil drilling.
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debates → emphasize → mining
The Aporia
