'Unusual' Newborn Bottlenose Dolphin Deaths Attributed To Largest Marine Oil Spill Event In History

Scientists have attributed the highly unusual newborn and fetal bottle-nose dolphin deaths to the catastrophic Deepwater Horizon Oil Disaster which took place in April 2010 in the Gulf of Mexico. They concluded a long and exhaustive study, confirming that dolphins found stranded on beaches in the northern Gulf of Mexico between 2010 and 2013 were fatally impacted by the disaster, known as the worst ever marine oil spill event in history.

The study primarily involving nearly 70 "perinatal" common bottle-nose dolphins found in the territories of Alabama, Louisiana, and Mississippi, concluded that they were most severely impacted by the deadly spill. Scientists were attempting to investigate the "unusual mortality event" in the hope to better comprehend the likely causes of the event. Postmortem study of the stranded animals carried out by experts associated with the United States Marine Mammal Stranding Network involved both on-field as well as institutional procedures.

Deepwater Horizon Oil Spill
[Image via Shutterstock]According to the Marine Mammal Protection Act, an unusual mortality event or UME is defined as follows.
"A stranding that is unexpected; involves a significant die-off of any marine mammal population; and demands immediate response."
Under the act, an Unusual Mortality Event or UME had been declared for dolphins and whales in the northern Gulf of Mexico from February 2010 onward.

In 2011, scientists observed abnormally elevated numbers of stranded stillborn and baby dolphins in the regions of Mississippi and Alabama between January and April of the same year. According to experts, distinct demographic characteristics and pathologic lesions were identified in bottle-nose dolphins found stranded between2010 and 2013 in parts of the northern Gulf Of Mexico.

More recently, efforts had been ramped up to examine dead as well as live animals that may have been stranded as a consequence. Previous studies had also identified associations between oil and hydrocarbon exposures, impact on animal immune systems, and failed pregnancies in terrestrial or inshore species.

GoM Oil Spill
[Image via Shutterstock]According to statistics, there are over 40 known species of dolphins, 38 of which are oceanic dolphins with five species of river dolphins. The bottle-nose dolphin is one of the most well known species of marine mammals. These dolphins have powerful bodies and thick beaks. Their appearance and size varies with color ranging from light gray to black depending on the animal's inshore and offshore characteristics, the terrestrial ones being smaller and lighter in color.

According to National Oceanic and Atmospheric Administration (NOAA) expert Dr. Teri Rowles, the co-author of the study, exposure to the deadly marine spill has contributed immensely to the unusual mortality event.

"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 dolphins living in the oil spill footprint in the northern Gulf of Mexico,"
The Deepwater Horizon oil spill, popularly known as the Gulf of Mexico oil spill, is the largest marine oil spill disaster in history. Deepwater Horizon was a deep-water, semi-submersible offshore oil drilling rig owned by Transocean. On April 20, 2010, an explosion on its platform triggered a colossal oil spill in the Gulf of Mexico with devastating consequences for the marine animals abounding in the region.

Gulf of Mexico Oil Spill
[Image via Shutterstock]In their research paper, contributing experts disclosed the final concluding observations regarding the investigation.
'This study supports that perinatal dolphins throughout Louisiana, Mississippi, and Alabama were susceptible to fetal distress and in utero infections during the northern GoM UME. Pregnant dolphins from Alabama and Mississippi, especially during 2011, were susceptible to earlier fetal losses than had been reported in previous years'
There is now common consensus that a staggering five million barrels of oil may have been released by the Deepwater Horizon disaster with nearly as much deposited into the waters of the Gulf of Mexico.

[Image via Shutterstock]