Captive Dolphins Need a Full, Rich Social Life

Debbie, a 56-day-old dolphin baby, swims next to her mother, Delphi, at the zoo in Duisburg, Germany, on February 17. The authors write that captive dolphins could live in the ocean while still being monitored and cared for by humans. They could swim greater distances, dive and learn to hunt for their own food. Wolfgang Rattay/reuters

Humans have long been fascinated with dolphins, which in more recent times has led to the animals' capture and confinement, including at theme parks like SeaWorld.

However, it's time to consider alternatives that reflect both current science and humane ethics. Many other species that humans have exploited are now allowed to live out their lives, with dignity, in sanctuaries.

As scientists researching free-ranging dolphins, we believe that they deserve the same consideration.

Like the lives of other social mammals, a dolphin's life is a mixture of physical, emotional and social survival. In their natural habitats, dolphins make myriad choices every day because of the complexity of both their habitat and social environments.

Well studied, free-ranging dolphin communities demonstrate repeatedly that bonds are strong between individuals. Free-living dolphins have both close friendships and lifelong relationships. Dolphins depend heavily on their peers and cohorts for a variety of aspects of life, including protection, learning, fun, procreation and, in some cases, even for their food, as they may hunt together in groups.

Dolphins not only have different personalities but also may play different roles in a group, such as babysitter, information broker or keeper of knowledge. It has become more and more apparent that the individual lives and roles of dolphins in their society can make or break that society.

In most captive situations, however, the social group is predetermined for a dolphin by humans, and she or he just has to fit in—or tough luck.

Dolphins use many forms of communication that include visual cues, such as body posturing, but acoustic signaling is even more important for them. One form of this is known as "signature whistles"—contact calls that are unique to each individual. These are established at an early age and influenced by the community at large. Dolphin etiquette and rules of signal use are specific and enforced over time through both observational learning and teaching.

In tanks, these sounds are reflected off the stark concrete walls, can be distorted and are possibly acoustically painful because of the lack of dispersal in a small body of water. In addition, background noise from pumps, loud music and rollercoaster rides (some tanks even have the footings for such behemoths placed beside or inside the tank) can hinder or even block communication channels.

It isn't hard to imagine that for an acoustically oriented animal, this is not a desirable living situation. It doesn't take a scientist to understand that being in a cramped tank in no way replicates a natural environment. Even if a dolphin has been bred in captivity, millions of years of evolution and instinct do not disappear overnight, nor even in a few generations.

In a seaside sanctuary or protected ocean cove, captive dolphins could be transitioned to live in large areas of the ocean while still being monitored and cared for by humans if necessary. They could swim greater distances, dive and learn to hunt for their own food. They could experience some of the diversity a natural habitat enclosure could offer, such as rocks, sand, seaweeds, other creatures and changing tides.

Dolphins in such a sanctuary could have the freedom of choice to socialize with other dolphins, to interact with humans or not, be involved in research or not: the choice would be theirs and their choice would be the priority.

After all we have done to the oceans and to dolphins, we can at least give those we have subjected to captivity the chance to retire with some dignity; to live their final years with these minimal freedoms. For some it may also be the stepping-stone towards true freedom and a life in the open ocean.

Denise L. Herzing is research director of the Wild Dolphin Project. Ingrid N. Visser is a scientist with the Orca Research Trust and the Free Morgan Foundation.