Deep-sea life in the Gulf of Mexico collapsed after Deepwater Horizon spill

A new study published in PNAS reveals that marine populations in the Gulf of Mexico’s deep-water ecosystems have collapsed significantly following the 2010 Deepwater Horizon oil spill. Research conducted between 2011 and 2023 indicates that fish populations plunged by approximately 63.5 percent, while crustaceans like shrimp and krill dropped by 62 percent. Larger species, including squid and octopuses, saw declines of nearly 60 percent.

The impact is most pronounced in the mid-water ecosystems, specifically the zone between 600 and 5,000 feet deep. This area, known as the deep scattering layer, accounts for more than 90 percent of the Gulf’s volume and supports a diverse complex of animals that migrate vertically to feed.

Researchers from Nova Southeastern University and Florida International University found that populations in these sites have been reduced to one-third or one-quarter of their former levels, with no meaningful recovery observed even 16 years after the release of 134 million gallons of oil. Scientists noted that natural variables such as temperature and oxygen levels do not sufficiently explain these losses, pointing to the spill as the primary driver of the ecological shift.