The Navy’s Dolphins Have a Few Things to Tell Us About Aging

After completing Blue’s exam, Dr. Linnehan and her colleagues trudged back up the hill to their offices, the chatter of dolphins and sea lions fading behind them. But even indoors, it was impossible to escape the animals’ presence: There were photos of dolphins, dolphin cartoons and a plushy toy sea lion. Anatomical models of dolphins sat on numerous desks.

The laboratory, located just a short walk away, is typically bustling after the animals’ morning medical checks, as technicians process any recently collected blood, urine, fecal or other samples. Later, the samples are stored in a small, windowless room across the street, where supercold freezers contain a marine-mammal biobank that dates back decades. “We’ve got animals here in their 50s,” Dr. Xitco said. “All their health records are upstairs, and their tissue samples are across the street. It’s just an amazing resource.”

This biobank has made it possible for scientists to do longitudinal studies, charting, for instance, how dolphins’ blood chemistry changes as they age. And the large, well-trained animal population allowed the Navy to pioneer new medical techniques, such as portable ultrasounds for dolphins. Dr. Sam Ridgway, who was the program’s first veterinarian and continued to publish new research until his death last year, became known as the father of marine mammal medicine. To date, research on the Navy’s animals has yielded more than 1,200 scientific papers, conference presentations and book chapters, Navy officials said.

“No question they have been a leader in terms of developing our understanding of dolphin medicine,” said Randy Wells, who directs the Chicago Zoological Society’s Sarasota Dolphin Research Program. (Dr. Wells frequently collaborates with the program’s researchers and has also received funding from the Navy.)

After their morning exams, the animals have training or enrichment sessions, often in the open ocean, where their athleticism is on clear display. The dolphins swim alongside boats, retrieve brightly colored balls, launch themselves into the air, slip under the water’s surface and reappear in a flash.

Dolphin day afternoon

But they do slow with age, Dr. Jensen said. Their energy levels flag, their joints stiffen and they put on some extra pounds. Some develop heart disease, kidney stones or vision problems, which can require surgical intervention.

A few hours after examining Blue, Dr. Linnehan joined her colleagues at the Marine Mammal Surgical Center to talk through some upcoming cataract surgeries for sea lions. The team has become more proactive, said Dr. Jenny Meegan, a senior veterinarian at the National Marine Mammal Foundation. The veterinarians now perform cataract surgery before the animals’ vision deteriorates significantly, she said, and are studying new diets that they hope will prevent dolphins from developing kidney stones.