One of the U.S. Navy’s team of bottlenose dolphins has been euthanized at the Space and Naval Warfare Systems Command (SPAWAR) facility on San Diego Bay.

The male dolphin – named Makai – had been suffering from old age, according to a SPAWAR statement emailed Tuesday to CBS News 8.

“Makai had been receiving critical care for ailments associated with old age,” wrote SPAWAR Public Affairs Director James Fallin.

Animal rights activists videotaped the dolphin in recent days being supported by flotation devices inside a medical pen and receiving constant monitoring at the Point Loma facility.

Navy officials announced the death in response to questions by CBS News 8 seeking information about the animal’s health.

“Today (Tuesday, April 11), one of our eldest dolphins, a 46-year-old male named Makai, and one of our most celebrated veterans of the Iraq War, was peacefully and humanely put to rest. He was a beloved and accomplished member of the Navy Marine Mammal Program team, and an American hero who lived to be more than twice the average age of dolphins in the wild,” the SPAWAR statement said.

The Navy Marine Mammal Program keeps about 85 dolphins and 55 sea lions in captivity on San Diego Bay, according to SPAWAR.  The animals are trained to detect underwater mines and scuba divers.

Makai was captured from the wild in 1974 and deployed to the Persian Gulf in 2003 during the Iraq War.