Topline
Twelve years after the Deepwater Horizons spill sent more than 210 million gallons of crude oil into the Gulf of Mexico, scientists at the National Marine Mammal Foundation have linked the disaster to genetic changes in bottlenose dolphins off the coast of Louisiana, according to a study published Wednesday in the journal PLoS One.
Bottlenose dolphins off the coast of Louisiana have shown changes in gene expression since the … [+]
Key Facts
Bottlenose dolphins exposed to crude oil that swelled into the Gulf of Mexico from the Deepwater Horizon spill in 2010 showed changes in immune response, as well as skeletal alterations and cellular dysfunction, according to the study, which compared RNA samples from dolphins outside Barataria Bay, Louisiana, with dolphins near Sarasota Bay, Florida.
The most dramatic changes were recorded in 2013, three years after the spill—the biggest offshore oil spill in U.S. history—and were more prominent in dolphins studied off the coast of Louisiana than in Florida.
Dolphins off the coast of Florida were found to be four times as likely to successfully reproduce as dolphins closer to the oil spill off the coast of Louisiana, which had a success rate around 20%, compared to 83% for Sarasota Bay dolphins.
The study adds to previous findings from veterinary examinations of Barataria Bay bottlenose dolphins that linked the effects of the oil spill to impaired reproductive, cardiac and immune function, as well as a weakened stress response.
Key Background
The Deepwater Horizons spill lasted 87 days, following an explosion at a British Petroleum well that killed 11 people in April 2010. It is estimated to have killed roughly 80,000 birds, more than 6,000 sea turtles and nearly 26,000 marine mammals. The population of Louisiana bottlenose dolphins has not come close to recovering, according to study co-author Sylvain De Guise, who spoke to NBC News. Numerous environmental restoration projects have been proposed, but there hasn’t been agreement on whether those projects could end up inducing unintended, and potentially deadly consequences. A National Marine Mammal Foundation study published in March found an initiative to provide fresh water from the Mississippi River into the Barataria Basin could inadvertently have disastrous results on dolphin populations by decreasing the salinity of the water.
Sfurther Reading
Deepwater Horizon spill linked to gene expression changes in dolphins (NBC News)
Deepwater Horizon Oil spill: no crude joke ten years on (Cosmos Magazine)
Source: https://www.forbes.com/sites/brianbushard/2022/08/24/bp-oil-spill-linked-to-abnormalities-in-dolphin-dna/