Pacific White-Sided Dolphins: Wild, Rescued, and Captive
Pacific White-Sided Dolphins in the Wild and in Captivity
Pacific white-sided dolphins are intelligent, playful, and very social animals. They live in large groups and often approach boats. They are attractive dolphins that are fascinating to observe in the wild. Unfortunately, they are also kept in captivity in aquariums and marine parks. Sometimes this is necessary because an animal has been injured. The rescued animal may no longer be able to survive in the wild, even after it has been treated. In my opinion, this is the only justification for keeping a dolphin in captivity.
This article tells the story of both the wild dolphins and the two rescued Pacific white-sided dolphins at the Vancouver Aquarium in British Columbia. Helen and Hana were deemed unreleasable and lived together at the aquarium for ten years. In 2015, a sudden and tragic illness claimed the life of Hana, despite some very impressive attempts to keep her alive. Helen swam in her tank alone for a while, but she currently has company. Chester is a rescued false killer whale who has also been deemed unreleasable. He and Helen are now companions.
The scientific name of the Pacific white-sided dolphin is Lagenorhynchus obliquidens. Like other dolphins, porpoises, and whales, it belongs to the order Cetacea. The animals in this order are often referred to as cetaceans.
An Attractive Animal
Pacific white-sided dolphins live in the northern part of the Pacific Ocean. Although their exact colouration varies, in general the animals have a black back, grey sides with a white or light grey stripe, and a white throat and belly. The dolphin's lips are black.
The dorsal fin on the animal's back has a strong backwards curve and sometimes looks hooked. The fin is black on its upper portion and grey on the lower portion. The animal also has a pectoral fin on each side of its body. Some people prefer to call the pectoral fin a flipper, since unlike the fin of a fish it contains bones. The flipper bones resemble a short version of the bones in our upper arm, forearm, and fingers. This reminds us that whales are mammals, like us, and that their distant ancestors were land animals. The dolphin's tail is made of two lobes called flukes.
Dolphins Swimming Beside a Boat
Life in the Wild
Pacific white-sided dolphins live in large groups that generally contain from ten to a hundred animals. They have also been observed in "supergroups", which may contain thousands of animals. They are sometimes seen in the company of other dolphin species or of whales. The dolphins frequently approach boats and ride on the bow waves. They are acrobatic and playful animals that often leap out of the water and do somersaults.
Like other cetaceans, the dolphins breathe through a blowhole on top of their head and need to come to the surface periodically to obtain oxygen. They can stay submerged for up to six minutes. They communicate with each other by whistles as well as by touch. Evidence suggests that each animal has its own signature whistle.
The dolphins feed on small fish and squid, which they find by echolocation. During this process, a dolphin emits high pitched sounds. The sound waves bounce off objects and return to the dolphin, giving them an impressive amount of information about their environment. This information includes the location of an object as well as its shape, density, speed, and distance. The dolphins are often seen herding fish as they hunt.
Pacific white-sided dolphins reach sexual maturity between the ages of seven and ten. The gestation period is twelve months. There seems to be a three to five year interval between births.
Dolphins Swimming Underwater
The Vancouver Aquarium
The Vancouver Aquarium is located in Stanley Park, which is located near downtown Vancouver. The aquarium is a non-profit organization dedicated to education, research, and conservation. It actively participates in all these areas. It's a popular institution for schools, tourists, and local people.
Like other facilities that house marine mammals, the aquarium periodically faces criticism from animal rights activists for keeping intelligent and sentient beings like cetaceans in captivity. The aquarium has evolved over the years, however. Since 1996, it no longer captures wild cetaceans. Any cetaceans that it does accept are either rescued animals that lack the skills to survive in the wild or animals born in other facilities. Some of the rescued animals come from the aquarium's own Marine Mammal Rescue Centre, which helps local animals in distress and releases them back into the wild whenever possible.
Another factor that draws the ire of animal rights activists is the death of a cetacean from anything other than old age. There have been several of these deaths in recent years. The survival of whale and dolphin calves has been a particular problem.
I have no doubt that the aquarium staff care deeply for their charges, as I've often observed. It's unnaturał for a marine mammal to spend its life in a restricted area that gives them little to do, however. It's hard to imagine that this doesn't affect their health and resilience.
Spinnaker, Hana, and Helen at the Vancouver Aquarium
Spinnaker, Hana, and Helen lived together at the Vancouver Aquarium. All three dolphins were rescued by a Japanese institution after becoming entangled in fishing nets. They were declared unreleasable due to their injuries. The pectoral fins on the sides of Helen's body were partially amputated as a result of her entanglement in the net.
Rumours persist that the dolphins were actually injured in the annual Taiji dolphin drive, a horrible event in which dolphins are caught for food and trapped for dolphinaria. The aquarium adamantly denies that this is true and say that Helen was rescued thousands of miles away from Taiji.
Spinnaker, the only male in the group, died in 2012 after a lengthy illness. He was about twenty-five when he died. Hana lived for twenty-one years. Helen is currently around twenty-nine years old. The maximum lifespan of Pacific white-sided dolphins is somewhere in the forties.
Helen and Hana performed in shows, as shown in the video below. Like the aquarium's policy on obtaining animals, the cetacean shows have evolved over the years. The animals no longer perform showy and unnatural tricks. The behaviours that they do exhibit during a show are ones that they perform in the wild.
Dolphin Show: Helen and Hana Perform
Hana's Illness and Death
On Monday, May 18th, 2015, staff members noticed that Hana was behaving abnormally. The aquarium's head veterinarian was contacted. With the assistance of "one of the world's top dolphin radiologists", the vet diagnosed gastrointestinal distention and inflammation. This is a condition that is known to progress rapidly and to be life threatening.
As Hana's condition worsened, the vet gathered together dolphin medical experts from around North America. They decided that the only treatment that had any hope of saving Hana's life was to perform the world's first intestinal surgery on a Pacific white-sided dolphin under general anesthesia.
Against all odds, Hana survived the surgery, which was performed on the Thursday evening of the week in which her illness was discovered. By Saturday morning she was showing some signs of improvement. Sadly, on Sunday morning her condition began to deteriorate. She died on Sunday evening.
The cause of Hana's death was reported to be a gastrointestinal illness. Helen never showed signs of the disorder. A post mortem exam showed that the passageway where Hana's small intestine joined her large intestine was unusually narrow, which is thought to have contributed to her problem.
Helen's Life on Her Own
Shortly after Hana's death I visited the aquarium and observed Helen. Every time she was at the water's surface in the shallow pool, she repeatedly lifted her head out of the water with a jerk while opening and closing her mouth. Her behaviour suggested that she had just regurgitated food. Each time I returned to Helen's tank after looking at other animals she was still performing this odd behaviour. It looked very much like the repetitive actions that some captive animals perform under stress. Regurgitation and playing with the regurgitated food is a known indicator of boredom in captive cetaceans.
Interestingly, I discovered a YouTube video showing the same behaviour taking place while Hana was alive. Both dolphins were in the small pool, even though the big tank was (presumably) available to them. I find it so sad that even then the dolphins were behaving in a way that suggested that they were bored. The video is shown below.
I think that the aquarium is a wonderful educational resource. There is far more to see there than just marine mammals. I also applaud the aquarium's rescue and research efforts. I think that much more needs to be done to support the cetaceans that live at the aquarium, however. They need to have more space, more enrichment with respect to activities, and a better life.
Stereotypical Behaviour in Pacific White-Sided Dolphins
How Could the Problem of Cetaceans in Captivity Be Solved?
The problem of eliminating the keeping of cetaceans in captivity or of improving their lives is not as easy as it sounds. The following methods have been suggested with respect to the Vancouver Aquarium's cetacean population.
Attrition: Some people have suggested that the aquarium's cetacean population should be removed by attrition. According to this plan, after each animal dies, no replacement would be brought into the aquarium. The problem with this idea is that the last animals would have a miserable existence, since they would have no company. Cetaceans are social animals.
Transfer: Another suggestion has been to transfer whales and dolphins to larger facilities which have more animals. This would solve the problem of the unhappy lives of the last Vancouver animals left by attrition. One possible problem is that in larger captive populations more breeding would occur, potentially increasing the size of the captive population. Still, the transfer could improve the lives of the Vancouver Aquarium cetaceans.
Enhanced Habitat: The aquarium's current cetacean habitats could be expanded and enhanced. Getting permission to expand further into Stanley Park—a major and much loved tourist attraction—is always difficult, however. In addition, some people worry that if the aquarium expands it will obtain more cetaceans. This is another controversial topic. From one perspective, obtaining more Pacific white-sided dolphins would be good, since it would create a more natural community for Helen. (Providing a suitable community for Chester could be an additional problem.) The dolphins would need much more space to enable them to live a reasonably happy life, however.
Rehabilitation and Release: It's been proposed that the cetaceans presently at the aquarium be released into the wild. This is not really a viable option. It would be very difficult to teach a cetacean that has been raised in captivity how to survive in the wild, even if we knew all the things that the animal needed to learn. The Marine Mammal Rescue Centre does rehabilitate and release cetaceans and other marine mammals, but all of these animals were rescued as adults or are able to survive in the wild. While it's true that Helen was rescued as an adult, she was deemed unreleasable in Japan due to her damaged pectoral fins.
Other ideas are being investigated to help rescued cetaceans and the problem of keeping them in captivity. One is the use of birth control drugs for captive cetaceans. Another is the creation of large sea pens to protect rescued animals and let them live a somewhat normal life.
Helen and Chester
In July 2014, the aquarium's Marine Mammal Rescue Centre rescued a young false killer whale (Pseudorca crassidens). He was stranded in shallow water on Chesterman Beach in Tofino, Vancouver Island, and was named Chester. He was only four to six weeks old when he was found. Chester was injured, in distress, and abandoned.
After receiving intensive care, Chester recovered well. However, he lacks important survival skills that he would normally have learned from his mother and other members of his species. Fisheries and Oceans Canada (a government organization) declared that Chester was unreleasable due to his lack of skills.
The Vancouver Aquarium says that false killer whales and Pacific white-sided dolphins have lived together successfully in other facilities. They decided to place Chester in Helen's habitat so that each animal would have company. The original plan was for Chester, Helen, and Hana to live together.
The aquarium staff introduced the animals with caution, allowing limited interaction at first, and were prepared to separate them if there was a problem. The animals accepted each other's presence, however.
Chester in his New Home
Personal Observations Made Shortly After the Introduction
Helen was introduced to Chester in July 2015. Based on my observations made during a visit to the aquarium soon after the introduction, the two animals were already reasonably comfortable with each other's presence in the same tank. They came very close together when being fed but not when they were left on their own. They were still getting to know each other, though. One of the aquarium staff said that the relationship between the two cetaceans was changing daily. It was an exciting time.
I was very happy to see that even when Helen voluntarily stayed alone in the smaller tank, she seemed much happier than on my last visit. She didn't exhibit any stereotypical behaviour and even seemed to be looking at visitors with interest.
Chester was treated with care after he was placed in the tank. The area right next to the windows of the underground viewing area was roped off and monitored by a staff member during my visit. This prevented Chester from being upset by actions such as people tapping on the glass. Far from being upset, he seemed to be curious about all the people watching him and posed very nicely for photographs.
Helen and Chester Perform
Helen gave a short and simplified performance during my July 2015 visit. It seemed that not much was being asked of her, which was nice to see. The performance was based on her natural behaviours. Chester already followed some instructions. When asked to do so, he opened his mouth to get his tongue patted and teeth rubbed, turned upside down to show his undersurface, and swam to a different trainer łocated nearby.
The video above was recorded in January 2016 and shows a more active performance by Helen. On a more recent visit to the aquarium, I saw that Chester now exhibits a wider range of behaviours on command, although they are still natural ones.
The Future for Helen and Chester
Today Helen and Chester are doing more than simply tolerating each other. They sometimes swim beside one other, which is a sign of socialization. The relationship seems to be going well, but I have some concerns about the future.
False killer whales are not as bulky as killer whales, or Orcas, but they are considerably larger than Pacific white-sided dolphins. I wonder whether the tank will be big enough for the two animals, especially as Chester grows in size. There will be enough space for them to swim, but whether there will be enough room for the animals to have a good life is questionable. I am also concerned about whether the animals will have enough things to do. I would hate to see signs of boredom appear.
An Unnatural Life
Another problem for the cetaceans is that they will have only one companion. Two animals is nowhere near a big enough community for either Helen's species or Chester's. Pacific-white sided dolphins form close knit groups in the wild. As some people have said, it's impossible for even the best aquarium or marine park to give cetaceans a truly natural life.
In the wild, Pacific white-sided dolphins travel unimpeded for long distances and in large groups in their search for food. They frequently vocalize or interact with each other in some way, creating a rich social life. This situation can't be replicated in captivity. For rescued animals, though, we need to do the best that we can.
I'll be watching the progress of Helen and Chester with interest. Hopefully they will stay happy and become great friends, even though they belong to different species.
Pacific white-sided dolphin information from NOAA (National Atmospheric and Oceanic Administration)
Facts About the Pacific white-sided dolphin from the Vancouver Aquarium
The official announcement of Hana's death from the Vancouver Aquarium
Chester the false killer whale will stay at the aquarium: an article from the Vancouver Sun newspaper
© 2015 Linda Crampton