Sixteen Years After Deepwater Horizon, Deep Sea Life Shows Few Signs of Recovery

Sixteen years after the Deepwater Horizon blowout released more than four million barrels of oil into the Gulf of Mexico, a broad survey of the deep-sea ecosystem shows little recovery and dramatic initial losses. Using acoustic surveys and thousands of net samples across a wide area, the study documents population declines of at least 60 percent in groups such as octopus, squid, krill, shrimp, and lanternfish in the years following the spill. The losses occurred in the ocean layer extending from roughly 600 feet to more than two miles deep, and the authors describe them as the fastest and most severe decline recorded for animal life in that realm.

The research also detected oil-related compounds in the tissues of squid and octopus and in fish eggs, and reports reduced genetic diversity in some populations. Those contaminant burdens can impair development, reproduction, and chemosensory functions used to find mates, creating lasting barriers to recovery. The study frames the Deepwater Horizon discharge as the most parsimonious explanation for the declines and warns that diminished genetic variation could leave deep-sea communities less able to adapt to ongoing environmental change.