Populations of animals in the abyssal zone of the northern Gulf of Mexico fell between 60% and 85% after the Deepwater Horizon rig spill on April 20, 2010, and show no clear signs of recovery, according to a study published on October 19, 2026, in Proceedings of the National Academy of Sciences (PNAS) and reported by Wired.
The ruptured well off the mouth of the Mississippi released crude for 87 days: 4.9 million barrels, plus 1.84 million gallons of chemical dispersants applied with authorization from state and federal agencies, according to Wired's reconstruction of the case. In 2016, BP accepted a $20.8 billion settlement, with up to $8.8 billion earmarked for environmental restoration. The finding matters to Mexico because the basin is shared: the abyssal zone holds close to 90% of the Gulf's total volume, according to the study, and it is where deepwater oil activity and high-seas fisheries coexist.
The data come from nine months of sampling in 2011, taken as a baseline, and from nine campaigns between 2015 and 2023. Using 10-square-meter nets down to 1,500 meters of depth and acoustic probes, the team documented declines of 63.5% in fish, 62.9% in lanternfish, 72.8% in krill and 59.7% in cephalopods, according to NOAA Fisheries' summary. Acoustic backscatter, used as a proxy for biomass, fell 40% in the surface layer at night. The authors ruled out temperature, oxygen and food availability as causes, and found loss of genetic diversity in three lanternfish species.
John Quinlan, a biologist at the Southeast Fisheries Science Center and a co-author of the work, noted that before the spill there were few measurements of what was happening in the deep open Gulf, according to NOAA Fisheries. The authors also noted that industrial deep-sea mining poses a risk of damage to these ecosystems before baseline conditions are assessed. Damage assessments and restoration work remain ongoing, and the data series ending in 2023 stands as a point of comparison for future sampling in the basin.
This article was drafted with the assistance of artificial intelligence from verified sources and reviewed by a human editor before publication.