Are military dolphins working in the Strait of Hormuz? Probably not, but they have been part of the U.S. Navy for decades

Sadie Steinheimer, right, and Tristan Smith, interns at the Navy Marine Mammal Program (MMP), care for Navy dolphins at Naval Information Warfare Center (NIWC) Pacific on May 5. (Mass Communication Specialist 1st Class Michael T. Eckelbecker/U.S. Navy via CNN Newsource)

With concerns about Iran laying mines in the Strait of Hormuz, U.S. Secretary of Defense Pete Hegseth was asked Tuesday whether Iran might turn to dolphins to help confront the U.S. Navy.

He said that he could “confirm” that Iran didn’t have dolphins to deploy as part of operations but said he would neither “confirm or deny whether we have kamikaze dolphins.”

One source familiar with U.S. operations in the Strait of Hormuz told CNN that the U.S. military isn’t using dolphins as part of its efforts in the Strait. But the U.S. Navy does, in fact, have a decades-old program to train dolphins to help detect mines.

The Marine Mammal Program is a part of the Intelligence, Surveillance, and Reconnaissance (ISR) Department within Naval Information Warfare Center Pacific. The department’s dolphins are not kamikaze dolphins in that they do not sacrifice their lives to detonate mines. Instead, they’re focused on detection.

“We use marine mammals to help detect objects under water and to protect ports by detecting intruders,” Scott Savitz, a senior engineer at RAND who previously worked with the now-decommissioned U.S. Navy mine warfare command, told CNN. “So it’s not ‘The Day of the Dolphin.’”

The U.S. isn’t alone in using dolphins for military purposes — Russia has used them to guard ports, and Iran purchased dolphins in 2000, according to the BBC. Those dolphins would likely be too old to be used today, and there is no indication that Iran has an active dolphin program, though the Wall Street Journal reported last month that Iran was considering mine-carrying dolphins as a novel way to combat the U.S. efforts to open the Strait.

The question to Hegseth on Tuesday comes amid questions about the ceasefire between the U.S. and Iran, after shots were fired by both sides as tensions escalated in the Strait of Hormuz. CNN reported in March that Iran had started laying mines in the Strait; Hegseth said in April that laying mines would violate the tentative ceasefire agreement and that the U.S. military would “deal with that.”

The U.S. Navy’s dolphin program has been around since 1959, focused on training bottlenose dolphins and California sea lions to detect and recover objects underwater. According to the Marine Mammal Program’s webpage, dolphins “possess the most sophisticated sonar known to science,” and underwater drones are “no match for the animals.”

“Both dolphins and sea lions have excellent low light vision and underwater directional hearing that allow them to detect and track undersea targets, even in dark or murky waters,” the website says. “Dolphins are trained to search for and mark the location of undersea mines that could threaten the safety of those on board military or civilian ships.”

During a detection mission, the dolphin would typically travel with 2-3 handlers in a small boat. To indicate if they’ve found something, the animal will tap a paddle at the front of the boat, and tap a back paddle to indicate they haven’t, according to the Naval Undersea Museum. The dolphins drop “marker buoys” near mines they’ve located to help human divers find and disable them.

But dolphins are not typically used in an active combat environment like what exists in the Strait of Hormuz currently. Instead, dolphins have been used to detect mines after fighting has finished, Savitz said.

Savitz pointed specifically to when dolphins were deployed in 2003 to detect any mines leading to the Iraqi port of Umm Qasr after the U.S. and coalition partners had captured southern Iraq.

“Hostilities had basically ceased,” he said. “You’re not trying to fight your way in with dolphins.”

A key aspect of the program, Savitz explained, is that the dolphins and sealions have the opportunity to leave every time they go out into the open waters for training or operations.

“They choose to come back because they like the free fish; they like the game of can you find this on the sea floor, can you find the person trying to swim close to the piers; they like the protection from predators,” Savitz said. “There are always questions about animal welfare, but these animals actively choose to stay in the program when they could just join the wild.”

CNN’s Zachary Cohen contributed to this report.

By Haley Britzky, CNN