Can Dolphins Commit Suicide?

Some people say yes, and some people say no. There are some evidence to suggest that dolphins in captivity have been seen to commit suicide. Speculations as to how they commit is that they bang their heads against the walls of oceanariums. Another way is that it is said that dolphins are conscious breathers and therefore poses both the cognitive intelligence to decide "not to breath" anymore.

However, there are counter-arguments against this. Some evidence suggest other reasons beside suicide that may explain why dolphins die.

Then there is the unexplained mystery of cetacean "mass suicide". Is it really mass suicide? Or is there another reason for finding multiple dolphin deaths on beaches?

Encyclopedia.com says "In situations of great stress in captivity they have been known to commit suicide by starvation, battering against walls, or drowning." ^[1]

A 2008 article on dailymail.co.uk says "Experts say dolphins have been known to take their own lives whilst living in captivity after becoming distressed and confused at their conditions. In several cases the creatures repeatedly slammed their head against sides of a pool - or simply stopped coming up for air." ^[2]

Begin in captivity is not natural for dolphins which swims in the wild 40 miles each day. They are also social animals that lives in pods that can be as large as 12 dolphins. A dolphin in an oceanarium is like a human under house-arrest not being able to go outside in their natural world.

Dolphins are voluntary breathers. That means they make conscious breaths by opening up their blowhole at the top of their heads. That is why they sleep with only half their brains asleep. One hemisphere of their brain is awake for breathing and other activity such as looking out for predators, while the other hemisphere sleeps. So it is quite possible that they can consciously decide not to breath or to not come up for air.

At least one person that believes adamantly that dolphins can commit suicide is dolphin trainer Richard O'Barry. He watched a dolphin named Kathy commit suicide when she decided not to take the next breath. Kathy was one of the dolphins used in the TV show Flipper. Richard O'Barry says "If life becomes so unbearable, they just don't take the next breath. It's suicide."^[3]

When asked in an interview "How do you know it was suicide?", O'Barry answered "Every breath for them is a conscious effort. She looked me right in the eye, took a breath, held it — and she didn’t take another one. She just sank to the bottom of the water. That had a profound effect on me." ^[4]

It was that suicide that turned O'Barry into an activist opposing dolphins captivity. O'Barry is heavily featured in the Oscar winning documentary film The Cove which tells of the killing of dolphins in Taiji Japan.

In order for an animal to be able to commit suicide, it needs to have a certain level of intelligence to form an intent to kill oneself. It needs to be self-aware of itself and its environment. It needs to have emotions about being depressed about its situation. Dolphins, along with humans and primates, are among the world's more intelligent creatures. And they are certainly self-aware and can recognize themselves in a mirror -- they pass the mirror test.

Dr. Lori Marino, a neuroscientist and marine mammal specialist, believes that dolphins have similar emotional traits and have the capacity of suicide due to its large brain and high level of cognitive abilities. [5]

It would seem that dolphin does poses a high enough intelligence level to consciously kill themselves.

In 2008 in Cornwall England, it had reported that 26 dolphins died after beaching themselves.^[6] Although the cause is not definitively known, some speculated that this might be a "mass suicide" after finding that they swallowed mud from the estuary. Even when the local residents pushed the dolphins back into the sea, they continued to try to beach themselves again.

It would seem strange that animals in the wild might commit mass suicide. But in 2007, ABC News reported a similarly speculative mass suicide where it was reported that 152 dolphins washed up on Iran's coast.^[7]

In both news reports, ships with ultra-sound devices was operating nearby which may affect the dolphins echo-location. In the case of Cornwall, the Royal Navy was playing war games that may include depth charges that panicked the dolphins into running aground. On the other hand, other article says that sonar may not be to blamed.^[8]

There is no doubt that there are beached dolphins. But a beached dolphin does not necessarily mean suicide. If it was a single individual beaching itself, it probably is because the animal is feeling very weak and is about to die and may go onto land to avoid drowning. Keiko, real life killer whale that starred in the film Free Willy died after beached himself on December 12, 2003. It was later determined that pneumonia was the probable cause of death.[reference]

Article on HowStuffWorks.com says "In 95 percent of the cases, these are animals in their final days, dying from disease, injuries or age-related maladies. In some cases, though, the animal is a stray calf." [9]

However, in mass beachings, the animals appear to be otherwise healthy. This perplexing situation is less well understood. One theory is that a single leader becomes ill or dis-oriented and beach itself and the rest follow.

Whales have also been seen committing mass beachings. Here is MSNBC video showing 35 pilot whales who beached themselves off an Irish coast. The video mentioned that some of them appeared sick when they came ashore, but a few were healthy but subsequently died. The don't have a definitive explanation, but one theories being considered are the effect of pollutants or sonar.

Article by John Dineley says that dolphin suicide in captivity is a myth.[10] Some dolphins may have unintentionally crashed into the walls of an oceanarium due to disorientation and panic when initially placed in the waters of its new unfamiliar environment. In another instance, a post-mortem revealed that a dead dolphin had swallowed pieces of wood and cloth.

Dr. Ann Weaver, who studies dolphins, does not believe in animal suicide. She says "I think suicide is the curse of the human consciousness, but not other consciousnesses. I don't believe they give up and that's what suicide requires." [5]

In order to be classified as a "suicide" the death must be intentional by the dolphins. Since we can not know the minds of the dolphins in these cases, it is impossible to say whether it was suicide or not.