Dolphin Therapy – is it worth it?
Dolphin therapy is presented as an effective and fascinating method of therapy recommended in autism, Down’s syndrome, cerebral palsy and many other disorders. Its effectiveness is allegedly due to contact with dolphins and ultrasound emitted by these animals. How much truth is there and is it worth taking dolphin therapy?
Can ultrasound heal?
Ultrasound is sound waves with frequencies higher than the human hearing range. There is no doubt that they have an impact on the human body at the appropriate intensity and frequency. The mechanisms of action of ultrasound can be divided into several types. One of them is thermal effects – the acoustic energy absorbed by tissues is converted into heat. Non-thermal effects can be divided into stresses and cavitation processes (high tensile forces causing bubbles to form in the liquid).
At the cellular level, ultrasound causes modifications in the cell membrane, changes in cell growth properties, changes in cell organelles (mainly in mitochondria), DNA damage (Miłowska 2007).
Ultrasound has been used in medicine for several decades. They are used, among others in the biological regeneration of athletes (Skalska-Izdebska et al. 2012), in rheumatic diseases, in wound treatment, in urology (for crushing kidney stones), in dentistry (removal of tartar), in laryngology (in sinusitis). Research is also conducted on their application in neoplastic diseases (Miłowska 2007). The application is therefore wide, but it does not cover mental disorders or mental retardation.
Can ultrasound emitted by dolphins heal?
Dolphin echolocation will not help for nervous system disorders, but maybe it helps with other diseases? Unfortunately. There is no evidence of that.
So far, only one study has been conducted on the therapeutic effect of ultrasound emitted by dolphins (Brensing et al. 2003). The authors of the study decided to check whether dolphins really show special interest in patients and whether ultrasound emitted by dolphins could potentially have a therapeutic effect.
Based on their knowledge of the use of ultrasound in medicine, researchers assumed that exposure to ultrasound was sufficient if it lasted at least 2 minutes during each session and the patient is under the influence of ultrasound if the dolphin is within 1 m and its head is directed towards the patient.
The study observed the behavior of five dolphins at a Florida dolphinarium. 83 30-minute sessions were recorded (30 sessions without people, 30 with tourists and 23 with patients). It turned out that one of the dolphins did show interest in the patients and spent more time around them than around other people. The remaining 4, however, were not particularly interested in patients. Moreover, even that one dolphin interested in patients spent time close enough and with his head facing the patients on average only 45 seconds during a 30-minute session. Given that 5-6 patients participated in the session simultaneously, each of them was exposed to ultrasound for less than 10 seconds. This time is too short for a therapeutic effect to be possible.
Dolphins as a motivator?
One of the pioneers of dolphin therapy (DAT – Dolphin Assisted Therapy) is David Nathanson, who does not try to prove the therapeutic effect of ultrasound (although he does not exclude that such an effect exists). He based the DAT therapy on the assumption that the learning difficulties of mentally disabled children and children with other severe disabilities are due to the difficulty in paying attention rather than the inability to process information. Swimming with dolphins can improve their attention span and increase their motivation to learn. He does not treat dolphin therapy as a miracle drug, but as a supplement to traditional forms of therapy. He also admitted that therapy with other animals can also increase the ability to focus attention. However, he believed that due to the intelligence and learning style of dolphins, and due to the fact that they stay in the water, which reduces stress, dolphin therapy is more effective than other forms of zootherapy (Nathanson et al. 1997).
Nathanson has conducted several studies on the effectiveness of dolphin therapy. In one of them (1997), he compared the effectiveness of a 2-week dolphin therapy to a 6-month traditional therapy. 47 children with various diseases (including autism, Down syndrome, mental retardation, cerebral palsy) participated in the study. Before starting dolphin therapy, each child participated in traditional therapy for 6 months. The examined children were divided into two groups. In group I, the therapeutic goal was to improve motor skills (e.g. putting a puck on a peg), while in group II – to improve verbal skills (speaking words or phrases). During therapy, dolphins were used as a motivator for learning. The children were rewarded for their correct response to the therapist’s request, e.g. by touching the dolphin or swimming on its back.
The results turned out to be very optimistic. In group I, 71% of children, after completing 2 weeks of therapy, were able to reach the object on their own and touch it or put a disc on a peg. In group II, 57% of the children said their first word.
In another study (1998), Nathanson studied the long-term effects of dolphin therapy. To this end, he asked to fill in a questionnaire of randomly selected parents from among those whose children had received one or two weeks of therapy at least a year earlier. The questionnaire was completed by 71 parents who answered questions in the form of “As a result of Dolphin Human Therapy, my child has retained or improved their skills ….”. They responded by selecting one of the options: never (0% of the time); 2 – rarely (25% of the time) 3 – often (50% of the time); 4 – usually (75% of the time); 5 – always (100% of the time); 6 – not applicable.
What results? The average response was 52%. The greatest improvement was in engaging in family activities and coping with special school activities, and the smallest in writing and reading.
David Nathanson’s research, while optimistic, nevertheless has many methodological shortcomings. This was noticed among others by Marino and Lilienfeld (1998).
First, Marino and Lilienfeld disagree with the theoretical foundations of Nathanson. According to them, it is not true that concentration difficulties are the main problem of children with disorders of the nervous system. They also note that Nathanson did not test the ability to focus attention either before or after the start of therapy, which makes it impossible to test the validity of his theory.
They also state that Nathanson’s research is methodologically incorrect. One of the shortcomings of the first study is the lack of a control group. It does not make it possible to say whether the results of the therapy are actually the result of this therapy, or maybe other factors, e.g. the experience of being in the water itself. It is also possible that there was a novelty effect, i.e. improvement was made because the child was exposed to new, interesting experiences. Such experiences often stimulate development and can also be provided by other stimuli than swimming with the dolphins. It should also be noted that many families came for therapy from distant US states and from outside the US. So the children had many new experiences: traveling to a new place, staying in a hotel, meeting new people, interacting with other children, etc. All of this could have contributed to their improvement.
Marino and Lilienfeld also pointed out, inter alia, the incorrect measuring of the test results. The people who assessed the behavior of the participants in the study knew what the purpose of the study was and what results are expected of the study children. Thus, there could be an expectation effect, consisting in the fact that the expectations of the experimenter affect the assessment of the behavior and sometimes the behavior of the subjects themselves. The trainers working with the children could therefore involuntarily direct them to the correct reaction. They could also involuntarily judge their behavior in their favor, for example say that the child put the puck on a peg on his own, although in fact they helped them a little.
The second study by Nathanson, assessing the long-term effects of dolphin therapy, was also criticized by Marino and Lilienfeld. First of all, it cannot be said that the improvement in behavior is due only to dolphin therapy that took place 12 or more months ago, if the child was in other forms of therapy in the meantime. The authors also noted that Nathanson only asked about the improvement of individual behaviors in the survey, and did not examine at all whether certain behaviors worsened, which could also have happened. Moreover, the parents’ responses are not objective. Parents who are very eager for their child to develop may be subject to a expectation effect. When asked if a given behavior improved, such as how often the child maintains eye contact, they could involuntarily recall only the moments in which the child made eye contact and note that this happened frequently, although in fact it was rare.
Review of research on the effectiveness of dolphin therapy
It is not only Nathanson’s research that is methodologically flawed. So far, several authors have reviewed the research on the effectiveness of dolphin therapy: Humprhies 2003, Marino and Lilienfeld 2007, Fiksdal et al. 2012. Everyone came to the same conclusions: the research is full of methodological errors, which does not allow conclusions on the effectiveness of interactions with dolphins.
So far, the best methodological (although also far from ideal) research on the effectiveness of dolphin therapy was carried out by Antonioli and Reveley (2005). They investigated the effect of interaction with dolphins on symptoms of mild to moderate depression. 30 participants of the study were randomly selected into the experimental group and the control group. Participants in the experimental group swam and played with dolphins for 2 weeks a day, while participants in the control group swim and snorkel on a coral reef for the same time. In order to avoid disappointment in the control group, which could deteriorate their mood, they, too, were allowed to swim with the dolphins after the study was completed and the questionnaires were completed by all participants.
The study found that people who swam with dolphins had a greater reduction in symptoms of depression than those who swam on a coral reef without dolphins. Dolphins aren’t the only animals that can help treat depression, however. Studies have shown that caged birds can also bring this effect, as well as taking care of cows on a farm (cited from: Kamioka et al. 2014).
Safety of dolphin therapy
A separate issue related to dolphin therapy is its safety, and I mean both safety for patients and for dolphins.
The dolphinarium is an environment completely different from the natural environment in which dolphins live. First, they are much smaller than the oceans in which dolphins live in large groups. The smaller area and separation from the family can cause great stress in dolphins. Secondly, chemicals are added to the water that reduce the risk of human infections but are not healthy for dolphins. There is evidence that in dolphinariums, the lifespan of these animals is often shorter than in the wild. They die from digestive system diseases, skin infections, heart disease, and more. There are also cases of dolphins committing suicide by refusing to eat or hitting the pool walls (Dima and Gache 2004, Grimm 2011).
When deciding on dolphin therapy, you should also know about the dangers of dolphins. These animals, although they look friendly and still “smile”, sometimes they are aggressive towards people. There is also a risk of contracting opportunistic bacteria, i.e. bacteria that dolphins live with on a daily basis, but which can be dangerous to humans. Adding chemicals to the water does not completely reduce this risk, as it happens that the dolphin breathes or urinates near humans (Brakes and Williamson 2007).
Is it worth choosing dolphin therapy?
Everyone should answer this question for themselves. While participating in dolphin therapy can indeed bring you benefits, there is no evidence that what is beneficial is the dolphin and not the other factors associated with the therapy. There is also no evidence that dolphin therapy is more effective than therapy with other animals, which are much cheaper.
The WDC organization (Whale and Dolphin Conservation Society) expressed a strong negative opinion about Dolphin Assisted Therapy:
- the considerable potential for detrimental impacts for both humans and dolphins in wild and captive DAT programmes;
- the high cost to participants, their families and dolphins involved in DAT;
- the fact that viable alternative therapy options exist;
- the fact that there are no official standards, or enforceable guidelines, relating to the provision of DAT and therefore that the proliferation of the industry around the globe continues unabated and totally unregulated;
- the fact that there remains no scientific evidence that DAT is any more effective than any other animal assisted therapy and it has not been demonstrated to have any long-term benefit;
it is highly recommended that the practice of dolphin assisted therapy be terminated.
In fact, even David Nathanson himself now believes that dolphin therapy should be abandoned. In 2007, he published the results of a study in which he compared the effectiveness of therapy with live dolphins and artificial dolphins.
For the purposes of the study, an animatronic dolphin (TAD – Animatronic Dolphin Test) was created, which size, color, texture, sounds and way of moving resemble a real dolphin. The study involved 35 children with various diseases, incl. with cerebral palsy, with autism, with mental retardation. Each child participated in sessions with live dolphins swimming in their natural environment (in the bay) and sessions with an artificial dolphin in the pool. Based on the results, Nathanson concluded that the artificial dolphin motivated to learn as well as the real dolphin, and in the group of children with the deepest disorders, the artificial dolphin even had some advantage.
- Antonioli C., Reveley M. (2005). Randomised controlled trial of animal facilitated therapy with dolphins in the treatment of depression. British Medical Journal, 331(7527),, 1231. (text at nih.gov)
- Brakes P., Williamson C. (2007). Dolphin Assisted Therapy. Can you put your faith in DAT? A report for WDCS, the Whale and Dolphin Conservation Society (pdf at uk.whales.org)
- Brensing K., Linke K., Todt D. (2003). Can dolphins heal by ultrasound? Journal of Theoretical Biology, 225, 99-105. (pdf at czydelfinoterapia.pl)
- Dima L.D., Gache C. (2004). Dolphins in captivity: Realities and perspectives. Biologie animală, Tom L,, 414-418. (pdf at uaic.ro)
- Fiksdal B., Houlihan D., Barnes A. (2012). Dolphin-Assisted Therapy: Claims versus Evidence. Autism Research and Treatment, 2012, 1-7. (pdf at hindawi.com)
- Grimm D. (2011). Are Dolphins Too Smart for Captivity? Science, 332, 526-529. (pdf at davidhgrimm.com)
- Humphries T. (2003). Effectiveness of Dolphin-Assisted Therapy as a Behavioral Intervention for Young Children with Disabilities. Bridges Volume, 1(6). (pdf at www.waterplanetusa.com)
- Kamioka H., Okada S., Tsutani K., Park H., Okuizumi H. i in. (2014). Effectiveness of animal-assisted therapy: A systematic review of randomized controlled trials. Complementary Therapies in Medicine, 22,, 371—390.
- Marino L., Lilienfeld S. (1998). Dolphin-Assisted Therapy: Flawed Data, Flawed Conclusions. Anthrozoös, 11, 194-200. (pdf at animal-friends-croatia.org)
- Marino L., Lilienfeld S. (2007). Dolphin-Assisted Therapy: More Flawed Data and More Flawed Conclusions. Anthrozoös, 20(3), 239-249. (pdf at animalstudiesrepository.org)
- Miłowska K. (2007). Ultradźwięki – mechanizmy działania i zastosowanie w terapii sonodynamicznej. Postępy Higieny i Medycyny Doświadczalnej, 61, 338-349. (text at phmd.pl)
- Nathanson D., de Castro D., Friend H., McMahon M. (1997). Effectiveness of Short-Term Dolphin-Assisted Therapy for Children with Severe Disabilities. Anthrozoös, 10(2-3), 90-100.
- Nathanson D. (1998). Long-Term Effectiveness of Dolphin-Assisted Therapy for Children with Severe Disabilities. Anthrozoös, 11(1), 22-32.
- Nathanson D. (2007). Reinforcement Effectiveness of Animatronic and Real Dolphins. Anthrozoös, 20(2), 181-194.
- Skalska-Izdebska R., Kuzian D., Pałka T., Gorzkowski K., Supowicz M. (2012). Wykorzystanie fizjoterapii w odnowie biologicznej sportowców. Young Sport Science of Ukraine, 3, 195-204. (pdf at ldufk.edu.ua)
Source of picture: Autor: Darkenrau (Praca własna) [CC BY-SA 3.0], Wikimedia Commons
Author: Maja Kochanowska