What’s Killing Gulf Dolphin Calves?

Dolphins swim next to oil booms at Petit Bois Island, MS, June 2010 (via Flickr's Deepwater Horizon Response)

Dead dolphins continue to wash ashore along the Gulf Coast. One aspect of the deaths that’s puzzling scientists – the odd distribution of dead calves:

The percentage of calf deaths among the total number of dolphin deaths is considerably higher in Mississippi and Alabama.

Nineteen of the 25 in Mississippi are calves and 18 of the 20 in Alabama are calves.

But for the region as a whole — the four states that make up the northern Gulf — there have been 81 dolphins of all ages reported dead this year, of those, 43 are calves.

Whatever is killing baby bottlenose dolphins in this area hit by the BP oil spill, it seems to be worst along Mississippi and Alabama — one-sixth of the affected coastline.

Only two of six dead dolphins found in the Florida Panhandle were calves and only four of 31 found in Louisiana, where the coastal oil impact was greatest.

Scientists are focusing on the Gulf oil disaster and an unusual cold snap as possible causes.

“As always we have to stress that the mortalities and other effects we do see are a probably fraction of the total impact,” said Dr. Ian MacDonald, member of the National Wildlife Federation’s Science Advisory Panel. “Porpoises are keystone species and vital indicators of ecosystem health – the canary in the coal mine. Whatever the cause might be, this kind of event underscores the vulnerability of the Gulf of Mexico ecosystem and should focus our resolve to see meaningful restoration begin now.”

Keep up with all the latest news on the Gulf oil disaster at NWF.org/OilSpill.