Nearly 80% of dolphins exposed to oil in the Deepwater Horizon disaster remain badly affected nearly 12 years later, according to new research, even as the Biden administration continues to approve leases for oil and gas drilling in the Gulf of Mexico.
Scientists looked at the long-term impact of the oil spill on bottlenose dolphins living in Barataria Bay, near New Orleans.
The lagoon off the Louisiana coast was heavily polluted by oil, which killed scores of dolphins directly or within months, and their population is now slightly over half of what it was.
The surviving dolphins did not escape ill effects, however, according to the peer-reviewed study in Conservation Biology. Lung disease has been the most common issue, according to Lori Schwacke, an epidemiologist of the National Marine Mammal Foundation who was the study’s lead author.
Other deterioration in the dolphins’ health has led Schwacke to believe the dolphins may be suffering from an illness similar to chronic obstructive pulmonary disease (COPD), a progressive lung condition. Age-related effects could also play a role.
Recent surveys suggest Barataria Bay’s bottlenose dolphin population has diminished by up to 45% since the disaster, to approximately 2,000. The reproductive success of the remaining females was significantly reduced.
Those dolphins born after the spill do not show signs of health impairment, however. “The hope is that, over time, the young animals will take over the population,” said Schwacke. Recovery to baseline numbers will probably take about 35 years, she estimated, providing there are no severe threats in the near future.
Last November, however, the US government leased huge parts of the Gulf of Mexico’s seabed for oil and gas drilling.
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