According to Popular Mechanics
Satellite images of a river in North Korea suggest the northeast Asian country is keeping a population of dolphins, likely for military purposes.
The pens appear similar to those used by countries that train marine mammals for military missions. North Korea’s aggressive military posture suggests it’s teaching dolphins to carry out attacks on enemy ships during wartime.
The location, spotted by U.S. Naval Institute News‘s H.I. Sutton, is on a tributary of the Taedong River, approximately 8 miles from the mouth of the river as it merges with the Yellow Sea. The location originally featured two circular-shaped pens, as seen above, that expanded to five pens within the last year. The pens first appeared in 2016.
According to Sutton, the pens are similar to those used by American and Russian military forces to keep marine mammals. Both countries have active marine mammal naval programs, with the animals trained to detect divers and saboteurs.
Dolphins in U.S. Navy service are referred to as Mark 7 Marine Mammal Systems and are trained to tag underwater mines for disposal by human divers. Sutton believes the Russian Navy sent dolphins to its base at Tartus, Syria to provide security for visiting warships.
The location of the alleged marine mammal pens has led to debunking charges that the pens are home to fish, not dolphins, meant for human consumption. The pens are different from aquaculture pens used by North Korea to raise fish. The country’s fishing farm pens are square and laid out in thick grids, and there are many examples along the Taedong River.
The pens Sutton observed are far from obvious fish farms and isolated. While salt water dolphins require salt water to survive in the long term, the location could easily be close enough to the ocean to offer brackish water with an acceptable level of salinity.
Why would North Korea train military dolphins? Pyongyang retains an arsenal of weapons—including artillery pieces, submarines, and commandos—to conduct small-scale attacks against South Korea. These attacks are meant to intimidate and gain leverage over North Korea’s southern rival.
In March 2010, a North Korean submarine sank a South Korean corvette, killing 46 sailors. North Korea never admitted responsibility for the attack. Later that November, North Korean artillery shelled Yeongpyeong island, killing two South Korean marines.