A U.S. Navy-trained dolphin named Marten, seen above, discovered an 1800s-era torpedo in San Diego Bay.
Don Bartoletti | Don Bartoletti Los Angeles Times | Getty Images
Defense Secretary Pete Hegseth on Tuesday dismissed the idea that Iran could weaponize marine mammals in the Strait of Hormuz and questioned the possible use of “kamikaze dolphins” as the country’s war with Iran continues.
Experts say the idea is not as far-fetched as it might seem. Several countries, including the United States, have a history of using dolphins in conflict areas, although not as weapons.
“I can’t confirm or deny whether there are suicide dolphins, but I can say for sure that there aren’t,” Hegseth said at a press conference.
Hegseth’s comments followed reports about that possibility. The Wall Street Journal reported on April 30 that Iranian officials said they could use “mine-laden dolphins” to attack U.S. warships. It is unclear whether Iran has that capability.
The term “kamikaze” was popularized during World War II to describe pilots who flew suicide missions against targets.
The Office of Naval Intelligence declined further comment, and CNBC referred to Hegseth’s Tuesday briefing.

The Strait of Hormuz has been largely closed during the war, and on Sunday President Donald Trump announced Project Freedom, an operation to free ships stranded in the Strait since the conflict began. Hegseth characterized the new mission as “separate and separate from Operation Epic Fury,” the war between the United States and Israel that began on February 28, and said the operation would not require U.S. forces to enter Iranian waters or airspace.
Fresh attacks on the vital waterway this week have reignited fears that the global economic fallout could be worse. Although the ceasefire between the United States and Iran remains officially in place, Iran has attacked the United Arab Emirates and the United States said on Monday that it had sunk an Iranian boat in the strait.
“The ceasefire does hold for now, but we will be monitoring it very closely,” Hegseth said.
Dolphins have a long history of military use.
U.S. Marines with dolphins trained to search for mines at the port of Umm Qasr, Iraq.
AP
Since 1959, the Navy’s Marine Mammal Program has trained bottlenose dolphins and California sea lions to detect mines and other underwater threats, conduct surveillance, and locate and retrieve objects at sea, according to the Naval Information Warfare Center Pacific, the Navy’s research and engineering laboratory.
“Dolphins are used in (military) exercises all over the world,” said Scott Savitz, a senior engineer and mine countermeasures expert at the RAND Corporation, a global policy think tank.
During the Vietnam War, the Navy trained dolphins to spot swimmers and divers trying to access military installations, Savitz said. He said the mammal also played a “key role” in detecting and clearing mines in Umm Qasr port during the 2003 Iraq war.
Dolphins and sea lions both have “extraordinary” abilities at detecting underwater objects, Savitz said. He said sea lions have excellent underwater vision and are commonly used to locate and retrieve objects in “cluttered” waters, while dolphins use echolocation, or biosonar, to search for mines in the open ocean.
K-Dog, a bottlenose dolphin belonging to Commander Task Force (CTU-55.4.3), jumps out of the water in front of Sergeant Andrew Garrett during a training exercise near the USS Gunston Hall (LSD 44) in the Arabian Gulf on March 18, 2003.
US Navy | Brien Aho | Reuters
Dolphins’ biosonars are often more accurate than electronic sonar, according to the Pacific Naval Information Warfare Center. They can “not only locate objects, but distinguish between them with more advanced capabilities than any machine we’ve been able to develop for this purpose,” Savitz said.
According to a 2022 NPR report citing analysis from the U.S. Naval Institute News, the Soviet Navy also trained dolphins for defense purposes during the Cold War, but the unit was transferred to Ukraine after the collapse of the Soviet Union. The Russian military reportedly revived the dolphin program after seizing Ukrainian defense dolphins in 2014 during the annexation of Crimea. The analysis revealed that in 2022, two dolphin huts in the port of Sevastopol were seen on satellite images.
“Challenge” of Dolphin Military Efforts
Experts say the use of dolphins in military operations raises complex questions about whether countries like Iran not only have trained marine animals, but also whether they have developed the expertise to work effectively with dolphins.
“The challenge for humans is to learn how to make the most of dolphin abilities,” Savitz said.
The question, he said, is “not whether Iranians can have a physical animal with some training, but whether Iranians have trained themselves to work with dolphins.”
Chris Jencks, a research professor of law at Southern Methodist University, said there are few ways to protect animals in armed conflict, but there are some legal strategies available under international humanitarian law.
A representative from the American Society for the Prevention of Cruelty to Animals referred to CNBC’s general position on military animals. The nonprofit said it “recognizes the value” of animals in military functions, but “animals should not be needlessly endangered or sacrificed for our country.”
According to the ASPCA website, “Military animals must be humanely trained and responsibly maintained, and our commitment to animal welfare must extend beyond the period of military service.”
Savitz said he has worked “off and on” with the marine mammal program for 25 years. “Dolphins and sea lions love this program,” he said.
“They exercise in the open sea every day,” he said. “They like free fish. They like to play with humans. For them, it’s play, just like drug-sniffing dogs or explosives-sniffing dogs.”
Savitz said no marine mammals were harmed during the military operation and “they are living healthy lives.”
