This is Scientific Americans 60 Second Science. I'm Steve Mursky. Got a minute?

The BP Deepwater Horizon oil spill began in the Gulf of Mexico on April 20, 2010.

Following the event through 2012, more than a thousand dolphins washed up dead along the

Gulf in three major strandings.

That's four to five times higher than the region's usual rate of dolphin deaths.

We found that dolphins dying after the oil spill had distinct adrenal gland and lung lesions that were not present in the stranded dolphins from other areas.

Kathleen Colgrove of the University of Illinois was the lead veterinary pathologist of the latest in a series of studies analyzing the die-off.

She and her study co-authors took part in a telephone press conference on May 20th.

Now surprisingly, one in three dolphins that stranded in Louisiana, Mississippi, and Alabama

had a thin adrenal gland cortex.

And when looking at just the baritaria bay Dolphins, half of them had this lesion.

Barataria Bay got an especially high dose of oil.

This prevalence was significantly higher than in the reference population, in which less than 1 in 10 had this lesion.

Now, the spinning of the adrenal gland cortex was a very unusual abnormality for us that has not been previously reported in dolphins in the literature.

Now aside from chemical exposure, conditions that can cause the adrenal gland to become thin include things like cancer,

autoimmune disease, fungal infections, and tuberculosis.

And we cannot find any evidence of these alternative causes in the

dolphins. Now in addition many dolphins dying after the oil spill again in

Louisiana Mississippi and Alabama

had evidence of significant lung disease.

And really in fact, these dolphins had some of the most severe long lesions I have ever seen in wild dolphins

from throughout the US.

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