(Grand Isle, La.) – Today, Audubon Nature Institute and the Louisiana Department of Wildlife and Fisheries in coordination with NOAA's National Marine Fisheries Service and Chicago Zoological Society's Sarasota Dolphin Research Program released a juvenile male dolphin into Barataria Bay. The dolphin is the first to be rescued, rehabilitated and released back into the wild off Louisiana’s coast.
“This is a truly notable event,” explained Mandy Tumlin, the Louisiana State Stranding Coordinator for marine mammals and sea turtles. “Dolphins can be deemed non-releasable for a variety of reasons, such as a medical condition that may hinder their ability to survive.”
On October 26, 2015, biologists from LDWF responded to a report by a private citizen of a live, stranded dolphin on Grand Isle Beach. Based on initial evaluations, the 6.5-foot-long juvenile dolphin was responsive. High water and rough seas associated with Hurricane Patricia likely contributed to the cause of the stranding.
“It’s unknown how long the animal was on the beach before he was discovered, but that period of time was a definite strain on him,” said Tumlin. “Dolphins are accustomed to buoyancy when in the water, so there is significant strain on their muscles when the animal is stranded and take on their entire body weight."
“We had a short window to diagnose whether the animal could be released or brought back to Freeport-McMoRan Audubon Species Survival Center (FMASSC) in New Orleans for treatment,” said Audubon’s Stranding and Rescue Coordinator Gabriella Vazquez. “He was lethargic and had short, shallow breaths. We attempted a soft release in the surf, but he showed no initiative to swim back into the Gulf.”
The dolphin was transported to FMASSC and made positive progress in the following months of evaluation and treatment. Named “Octavius’’ in an affectionate nod to the Audubon veterinarian caring for him, the dolphin responded well to treatment and was able to swim on his own.
In order to determine if the dolphin was a candidate for release, specific milestones needed to be met. First, he was required to pass behavioral clearance. Vazquez explained: “Octavius showed no signs of abnormal swimming, breathing or diving behavior. Importantly, he had not become desensitized to humans – which is crucial because human interaction with dolphins in the wild can be a problem.”
Tumlin further explained, “Animals can often become dependent on humans for food and other resources following time in rehabilitative care. Dolphins are very intelligent animals. Over time, they can learn to associate humans and boats as a source for food, which is why it is illegal to feed them in the wild.”
Next, the dolphin passed an “auditory evoked potential test” administered by Dr. Dorian S. Houser, Ph.D., Director of Conservation and Biological Research for the National Marine Mammal Foundation, and showed no signs of hearing impairment.
Finally, Octavius passed medical clearance, including blood work and veterinary examinations, showing no indication of congenital defects or medical issues that would hinder his ability to survive in the wild.
Because Octavius was only 190cm in length at stranding, he could be as young as 1 year or as old as 7 years (best age estimate is ~3 years). Because there is the possibility that he could be a dependent calf (if he were 1-2 years old), he is being considered a “conditionally releasable” animal. Both LDWF and Audubon are responsible for stringent post monitoring protocols outlined by NOAA/NMFS. Staff will be required to monitor this animal in the wild over the next six weeks.