Researchers looking into the largest dolphin and whale die-off on record in the Gulf of Mexico following the 2010 BP oil spill have tied a spike in the number of dead babies and stillbirths to the massive spill.
Since the spill, more than 1,400 dolphins and whales have been found dead in the northern Gulf of Mexico, the most ever documented. Last year, researchers with the National Oceanic and Atmospheric Administration reported that dead adults found in areas hardest hit by the oil between 2010 and 2012 suffered damage to their adrenal glands or had bacterial pneumonia. Such ailments have been previously documented in animals exposed to oil.
On Tuesday, the team reported that 88 percent of the nearly 360 babies and stillbirths found within the oil footprint had abnormal or under-developed lungs. Only 15 percent found outside the spill zone suffered from similar problems, according to the study published this month in the journal Diseases of Aquatic Organisms.
The team also found that dolphins in the spill zone were more likely to lose their babies and suffer infections during their 380-day gestation periods.
“Our new findings add to the mounting evidence from peer-reviewed studies that exposure to petroleum compounds following the Deepwater Horizon oil spill severely harmed the reproductive health of dolphin living in the oil spill footprint,” veterinarian Teri Rowles, who is overseeing NOAA’s study of the ongoing die-off, said in a statement.
The team has been looking into the die-off that stretches from the panhandle of Florida to the border of Louisiana and Texas, after the Deepwater Horizon spill dumped three million barrels of oil into the northern Gulf over 87 days. Researchers have documented 12 such die-offs of dolphins and whales in the region in the past, tied to two more common lethal viruses, morbillivirus or brevetoxicosis. Neither have been found in the ongoing die-off, they said.
Other studies have linked to the spill ailments ranging from heart defects in tuna to hampered swimming in mahi. Researchers also fear that as many as 320,000 migrating sea turtles could have been exposed to the oil slick that spread across 16,000 miles of coast.
Because their dolphin findings are based only on the number of dead that washed ashore, the total number of deaths is likely far higher, researchers said. They are continuing to look at the the overall health of dolphins to determine whether there are lasting problems and whether the oil has taken a bigger toll on dolphin reproduction.
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