When I left the US in 1988 to travel in Australia, I had no idea that I would
end up working with a group of captive dolphins in Perth, the capital city of
Western Australia. Although I had been contemplating my return to University
and several years of study for my Ph.D., and had been on the lookout for a
suitable research project, I had always intended my work to be on the social
behavior of wild dolphin populations. But while I was working as a field
assistant on just such a venture up the coast from Perth at Monkey Mia, I heard
about the Atlantis Marine Park project. The Park had closed down, leaving 9
bottlenose dolphins without a home--or, at least, without a captive home. The
enterprising marine park veterinarian and research scientist, Dr. Nick Gales,
had proposed that releasing the dolphins back into the wild would be the best
option for the animals' future and would be possible given sufficient time and
funding. The owners of Atlantis Marine Park (Tokyu Corporation of Japan)
accepted his proposal and agreed to fully fund the project provided that the
release would end their financial commitment to the dolphins. The State
Government wildlife department gave its stamp of approval, and the project was
ready to begin.
Atlantis Marine Park was constructed in 1981 in Two Rocks, a small fishing
community 60 km north of Perth. The owners had hoped Perth's rapid expansion
would be accompanied by an equal growth in tourism. During the six months
prior to the Park's opening, 7 bottlenose dolphins were captured from the local
coastal population. They were trained and maintained as performance animals
for the next 10 years. Unfortunately, the hopes for Atlantis proved ahead of
their time, and the park was gradually losing money. The birth of 3 female
calves in 1988, coupled with changes in regulations for holding marine mammals,
meant that Atlantis would have to construct a larger dolphin enclosure. The
owners decided to cut their losses, and Atlantis closed down in August 1990.
At that time it was home to 9 dolphins: 6 wild born adults (3 males and 3
females) and 3 captive born juvenile females.
Dolphins had occasionally been released from marine parks, but few of these
releases had been properly conducted and documented. They had often involved
simply returning an animal to the ocean without sufficient preparation and
follow-up work. More recent release projects have involved more preparation
and follow-up effort, however, the best example being the "Welcome Home
Project" run by Drs. Randy Wells and Ken Norris in 1988-90. They had captured
2 young male bottlenose dolphins from a much- studied population in Tampa Bay,
Florida. After 2 years in captivity, the dolphins were successfully released
into their native community, where they quickly reintegrated into the wild
population and are still sighted today.
Nonetheless, the Atlantis project would be unique and important for several
reasons relevant to the possibility of future cetacean reintroductions. Not
only were we planning to release long-term captives, but also dolphins born in
captivity. We hoped that by carefully planning and documenting the
rehabilitation and release process, the project would provide baseline data and
guidelines for future releases by determining what techniques and protocol were
useful, and which aspects were unnecessary or flawed. Ultimately, we hoped to
be able to suggest ways of easing the animals back into the wild, and to
provide information about the chances of success, thus spelling out some of the
implications of the transition, not only for long-term captives no longer
required, but also for endangered species that could conceivably be bred in
captivity and released into declining populations.
The rehabilitation process to prepare the dolphins for return to the sea began
in earnest in March 1991, 6 months after the closure of Atlantis. We carefully
considered the change in lifestyle the dolphins would be undertaking and the
problems they might encounter. At sea the dolphins would have to contend with
occasional food shortages, inclement weather, hostile dolphins and disease.
They would have to navigate and move through their environment avoiding
predators inappropriate prey, humans and fishing gear. With these thoughts in
mind, coupled with advice from a host of experts, we planned a rehabilitation
program to help the dolphins recover and enhance (or, for the captive born,
develop) these natural survival skills.
Rehabilitation began in the Marine Park pools. After the closure of Atlantis
the dolphins were no longer participating in shows and most performance
behaviors were dropped from the training regimen. The trainers focused instead
on husbandry and handling behaviors which involved moving the dolphins into
different positions, asking them to present various body parts and allowing a
trainer to stroke or handle them. These behaviors are useful in assessing the
dolphins' health without causing stress and could be useful at sea for
monitoring condition. Chlorine was removed from the water to accustom the
dolphins to untreated water. Although the dolphins had no problem with this
change, algae began to take over the pool, making it difficult even to see the
dolphins. The practice was therefore discontinued.
All dolphins were freeze-branded (on both sides of their dorsal fin) with a
number 2 cm high. While dolphins are individually recognizable, it takes time
and experience to notice differences reliably, e.g. darker color, a nick out of
the dorsal fin, or a mark near the blowhole. The freeze brands would make the
dolphins instantly recognizable by local fishermen and members of the public.
Foraging skills were tested and developed by feeding the dolphins live fish
that had been caught locally, thus ensuring they would be fish species that the
dolphins would encounter at sea. From the very beginning the dolphins were able
to capture live prey, and their skills improved over time. Nonetheless there
was a lot of variability between individuals and between trials. Among the
adults the more dominant animals tended to be the most aggressive and efficient
at fish capture. One male in particular was known to be highly food motivated,
and he had the highest capture rate (he could even capture fish while he still
had several previously caught fish in his mouth!). Although the juveniles were
all able to catch fish, they did not show the same capacity as the adults.
They seemed to treat the exercise as a game and would often all chase the same
fish, competing more with each other than actually showing any ability to
forage. It was a long time before we were sure that all of the dolphins could
catch and eat live prey.
One of the more difficult changes was limiting human interaction with the
dolphins so that they would spend more time interacting with each other and
less focusing on events above water. At this time I began a study of the
social behavior of the group. I was interested in the social relationships
between individuals, how these were expressed, and whether changes would occur
through the process of rehabilitation and release. The research involved
endless hours of standing at the pool-side, recording details of interactions
between individuals, group composition and general activity. I focused my
studies on the 3 males and a colleague looked at associations among the females
and juveniles. We had to be careful not to interact with the dolphins and
encourage more human interaction at a time when it was supposed to be reduced.
This was not easy, as the dolphins were always aware of our presence. We would
often have to wait 10 to 20 minutes for them to realize that we were not there
to play, pet or feed them and then settle down and go back to their own
activities. The juveniles were particularly keen for attention and would spend
quite a bit of time peering up at us, occasionally trying out a new activity to
test our response. A favorite of their antics was to perform a behavior in
unison. Although the juveniles were never formally trained, they copied the
performance behaviors displayed by the adults during feeding sessions. Quite
often, while we were trying to record observations of natural behavior, the
juveniles would all stop, watch us for several minutes then in perfect unison
embark upon a series of tail slaps or pec waves. We did our best to ignore
them, and the dolphins would eventually return to playing and swimming among
themselves, with just occasional bouts of observing the observers.
This part of the project gave me a fascinating glimpse into the personal lives
of the dolphin group. Like any social species, the dolphins all had "friends"
and, if not enemies, those with whom they rarely interacted. Each had a "best
friend" with whom they spent most of their time and with whom they engaged in
friendly actions like rubbing and side by side swimming. Changes occurred in
these relationships, accompanied by bouts of aggression and tension in the
group. The relationships we noted were similar to those reported in wild
dolphins populations: adult females had strong bonds with their offspring and
adult males formed bonds with each other and did not tend to interact so often
with the females. Spending so much time observing the dolphins also brought
home their unique "personalities", evident in the way they interact with others
and with the trainers. For example, one juvenile (Nakita) enjoyed playing with
rings and balls. Whenever any toys were present in the pool she was guaranteed
to be in charge of them, often playing with several rings at a time. She would
even approach the dominant male to take a favorite toy away from him. Of
course we all had our favorites and, although the juveniles were the most
amusing, I had a soft spot for Rajah, one of the adult males. He was a
relatively quiet dolphin, often alone and a bit persecuted by the other males.
But he was very friendly with people and would drift by the side of the pool
for as long as you were willing to stroke him.
An additional aspect of the release was an examination of the behavioral
ecology of the local coastal population. Although bottlenose dolphin
populations have been studied around the world, there had been no previous
research around Perth. It was important to have information on the behavior,
ranging patterns, and foraging strategies of local wild dolphins in order to
determine whether or not the Atlantis dolphins were integrating properly. A
survey project began in March 1991 and continued through June 1993, using
photographic surveys to collect information on dolphin group size, structure
and composition, general activity, range and association patterns.
The next stage involved moving the dolphins to a large sea pen in the Two Rocks
marina. This was to serve as a "halfway house" where the dolphins could
experience a vast increase in living space and could acclimatize to features of
life at sea: fresh sea water, fish and vegetation species and limestone reef.
Two new behaviors were introduced; response to an underwater recall signal and
following or bow riding with the research boat. While these behaviors are not
necessary for life in the wild, we hoped they would aid us in finding and
monitoring the dolphins after release. We also hoped to reduce the stress of
release by leading the dolphins out on excursions, venturing further and
further from home base, allowing them to gradually become accustomed to the
The dolphins were moved to the sea pen in October 1991 and adapted quickly to
their surroundings. All seemed eager to follow and interact with the boats.
The close relationships identified at Atlantis persisted between the females
and their offspring and between 2 males. The live fish trials were discontinued
in the sea pen because the size of the pen and lack of clarity of the water
made it impossible to determine who was catching fish. A local fishing company
donated a 1 ton school of yellowtail that were released into the sea pen in the
hopes that the dolphins would naturally forage from the school. Unfortunately,
the dolphins by and large ignored the fish school, although they would catch
and eat fish that were tossed near them. The school, however, did decrease
over time, and coincidentally the local cormorant population simultaneously
boomed! It is possible that the yellowtail were too small -- all were less
than 6 inches in length -- to be worth the effort of chasing, considering that
the dolphins were still receiving their normal daily allotment of fish. An
addition to the group came in November 1992 when an adult female (Mila) gave
birth to a male calf.
The final preparation involved fitting the adults with radio transmitters so
that we would be able to locate the dolphins at sea. The transmitters chosen
were about the size of a matchbox with a flexible antenna that would extend the
length of the dorsal fin. The whole package weighed 101 g. We carefully
observed the dolphins for several days to ensure there were no physical
problems with the attachment site or with inhibition of normal activity.
Transmitters were not attached to the juveniles as we did not want to add any
stress to the young, growing animals. We also hoped that the juveniles would
remain with the females a least in the early stages of the release. Dolphin
group structure in the wild is fluid, meaning that group size and composition
changes regularly. However, some individuals are often seen together
regularly, e.g. females and their offspring, and pairs of males who form long
term bonds. While we did not expect the Atlantis dolphins to remain together
permanently at sea, we hoped that some of the associations noted in captivity
We finally decided the dolphins were ready for release, and the gates to the
enclosure were removed on 14 January 1992 (mid summer in Australia). After
this time the dolphins had free access to the marina and the ocean beyond.
Initially, however, they displayed little or no interest and had to be coaxed
through the gates. Feeding sessions took the form of brief boat excursions
leading the dolphins out of the sea pen and around the marina until they left
the boat and returned to the pen.
The very next day Rajah accompanied the boat out of the marina where he left us
behind, heading out to sea. We gathered our tracking gear and set off in
pursuit for a very exhilarating 3 hours. During that time Rajah was seen
interacting with 2 different groups of wild dolphins. While the first was only
a brief encounter, Rajah changed direction and joined the second group
(consisting of 1 adult, 2 juveniles and a female and calf). Rajah remained
close to the 2 juveniles, occasionally synchronously surfacing with them and
engaging in friendly tactile interactions. Interestingly enough Rajah was
always the first to surface after a dive, sometimes coming up for several
breaths before the rest of the group, an indication that his fitness level may
not have been quite up to that of wild dolphins accustomed to regularly
travelling long distances.
After an hour Rajah again changed direction and left the group. Due to
worsening weather conditions we had to leave him shortly afterward. We didn't
see Rajah again for 10 days after this promising start, but received reports of
his whereabouts and heard his radio signal twice. He traveled 75 km south
where he remained in a large bay for several days before traveling 150 km
north, where he was sighted at a beach. The following day (10 days after
leaving the sea pen) he was found outside the Two Rocks Marina interacting with
several children on the rock wall. He approached our boat so eagerly that we
though he might jump aboard, and then followed us into the sea pen. Upon
closer examination it was obvious that Rajah had lost a great deal of weight
during his 10 days at large- 18 kg, or 10.8% of his pre-release weight. He
also had several scratches on his belly and tongue, indicating that he had not
been foraging properly and perhaps had been trying to eat such inappropriate
prey as spiny fish or lobster. Rajah was reinstated in the sea pen in order
that he regain condition.
In the meantime the remainder of the dolphins had left together on 16 January
with the exception of one of the juveniles (Echo) who was found alone in the
marina. She was subsequently captured and reunited with the group at sea. We
followed the dolphins for 9 hours that day, during which time they traveled 18
km north, milled near a reef then turned back to the south. Initially the
dolphins' behavior was rather erratic and none would approach the boats.
However, after several hours at sea they appeared much calmer, slowed down to a
slow and steady travel pace and occasionally approached us, though not in
response to the underwater signal.
The first inkling of trouble came the next day. The dolphins were located
readily enough, some 45 km south where they spent most of the afternoon milling
near a beach. Due to rough weather we could not stay at sea, but monitored as
best we could from land. Reports were received of the dolphins interacting
with people on the beach, and of the new born calf being helped into deeper
water on several occasions after nearly beaching himself. One final check on
the group at the end of the day revealed that a split had occurred; one of the
juveniles and the two males were no longer present.
The next few weeks involved many hours of boat time and worry as the group
disintegrated further and individuals proved more and more difficult to locate.
Unfortunately, once the juveniles left the adults, we could not find them save
for happening on them at sea or by reports from the public. Thus two of the
juveniles went missing within the first week and were not re-located. One
other juvenile (Echo) also left the group but was regularly sighted visiting
beaches. We finally caught up with her after 8 days at sea. She was obviously
losing weight and not making much effort to forage, but spending most of each
day at beaches and rock jetties interacting with people. We recaptured her and
returned her to the sea pen where she was reunited with Rajah. She had lost 10
kg or 8.5% of her body weight in those 8 days at sea.
After this time we were only able to locate the two adult males and Mila with
her new born calf. The two males stayed together for at least 8 days (a record
for the group) and traveled as far as 75 km south of Two Rocks before going
their separate ways. One of the males was re-sighted when he joined up with
Mila and her new born calf for three days, before moving off on his own. He
has not been sighted since that time (18 days post-release).
The other male ventured south, and was found over 350 km away on his 17th day
at sea. He was sighted in this area for a further two weeks, often by divers
and people at beaches. Although no one on the research team actually saw him,
we heard his radio signal several times and received video footage of his last
two encounters which showed that his appearance was fine and indicated good
health. However, he has not been seen or heard from since 16 February 1992
(one month after leaving the sea pen).
That left us with just Mila and her new born calf to worry about. They were
regularly sighted 25 to 35 km south of Two Rocks after the group disintegrated
and it became obvious that both were losing weight. The decision was made to
feed Mila from our boat, but after four weeks at sea her calf went missing and
can be presumed dead. At about the same time Mila's radio tag failed, making
it very difficult for us to find her. However, she began approaching and
following fishing boats, presumably begging for fish, and we were able to track
her down with the help of local fishermen. When we found Mila again her
condition had improved slightly, but she was still underweight and her choice
of foraging methods -- following boats and accepting fish handouts -- was
considered inappropriate, potentially dangerous, and evidence that she was not
integrating properly into the wild. Mila was never seen interacting with wild
dolphins, although on several occasions groups were nearby. We decided to
recapture her and return her to the sea pen with Rajah and Echo. This was
accomplished on 28 February. After 44 days at sea Mila showed a weight loss of
23 kg (15% of her pre release weight) despite receiving substantial fish
handouts during the last two weeks.
After 28 February 1992, none of the Atlantis dolphins were encountered at sea
again. We continued boat surveys for a further 16 months and used the radio
tracking equipment for the first two months of this. Several aerial surveys
were conducted covering up to 700 km in either direction of the release
site-but no signals were heard. We continued to receive reports from the
public and examined them as far as possible. Unfortunately many turned out to
be inconclusive or inaccurate. Although public reports can be a useful aid,
they are often unreliable. We only accepted as conclusive those reports
corroborated by a research team member, photographs or video footage. However,
in May 1992 we received some promising reports of a dolphin, sighted 981 km
north of Perth, bearing a striking resemblance to one of the released adults.
A similar report was received in September from a further 200 km up the coast,
however, neither of these sightings could be corroborated as we would have
The three animals returned to captivity were restored to peak condition by the
end of May 1992. A new home had to be found for them as we considered that
they could not be successfully or humanely released. Not only did we lack
sufficient resources for tracking at sea, but their difficulties in the first
trial proved they were not well adjusted for life in the wild. Fortunately a
local aquarium, UnderWater World, decided they would like to expand and to
include the dolphins among their exhibits. A new sea pen was constructed in
Hillary's Marina and the dolphins moved to this new location, where they
remain. The dolphins participate in several educational shows daily and have
recently been involved in a swim-with-people program. The females have each
given birth to a calf and all have remained healthy in their new home. A wild
dolphin regularly visits the enclosure, often spending hours swimming and
drifting near the net.
It is difficult to assess the success or otherwise of our project. I would
like to be optimistic and to think that the other five released dolphins are
healthy and have integrated completely into the wild population. More
realistically, it is likely that at least some of them had problems foraging
and integrating into wild groups. In either case, we can be sure of the
lessons that we learned, and of their applicability to future marine mammal
releases. First, we learned that not all animals are suitable candidates for
release into the wild. Length of time in captivity, captive conditions,
medical history and a dolphin's behavioral tendencies all affect the likelihood
of successful release. To even try to release some candidates will mean
placing them under severe stress and discomfort, or risking mortality.
Second, we found that it is crucial to ensure that natural survival skills have
been honed sufficiently. Long-term practice of foraging skills in a natural
location is essential. In our release, at least three dolphins had indicated
in captivity that they had a capacity for pursuing and catching fish, yet
failed to do so adequately in the wild. We shall never know whether the
problem was with locating, recognizing or catching prey. Supplementary feeding
is often used to help animals through the early stages of a release but this
might not be appropriate for dolphins, as we found with Mila. Feeding her from
our boat seemed to encourage her to view boats as a food resource and to
approach and beg indiscriminately, a behavior which placed her at risk.
Finally, and perhaps most importantly, any release must have available
sufficient technology to track animals after release in order to ensure their
well being. Only with proper tracking technology is it possible to undertake
even minimal health and behavior assessments and to step in if needed. In this
study, funding limitations and the state of tracking technology prevented us
from reliably locating the dolphins for any length of time. Technology has
since improved and satellite tags (which are ideal for long term tracking) can
be attached to dolphins.
Working on this project gave me some invaluable experiences. I had the
opportunity to work closely with a species I find fascinating in circumstances
where interaction was not only allowed, but inevitable. The project gave me
the opportunity to develop and clarify my ideas about captivity, reintroduction
and aspects of animal ethics. I found that my views on and appreciation of
reintroduction, captive conditions and captive research changed. Like so many
others, I do not like to see animals confined in captivity, even though I
appreciate the contribution of captive animals to our knowledge about dolphin
health, physiology and husbandry. My experience with the Atlantis dolphins
taught me that there is much to be learned from studying behavior in captivity.
Having dolphins maintained in a small area with the same group members allows a
much closer examination of specific behaviors and social interactions. A
colleague and I were able to identify strong associations between individuals
and postulate some theories which might be tested in the case of wild dolphin
social patterns. We were also able to identify changes in associations and
aggressive interactions that might have been involved in health problems
experienced by the dolphins. Thus monitoring behavior in captivity not only
teaches us about dolphins' social lives, but also about how best to monitor
health and improve captive care. I left the project with a much more positive
attitude towards captive research.
My involvement in this project also changed my attitude and perception of
releasing captive animals into the wild. Initially I strongly favored release,
believing that to return animals to their natural habitat after years of
confinement was an admirable goal as it seemed to guarantee improvement in
living situation and welfare. But as the release developed and I was faced
with the difficulties encountered by the dolphins and their obvious decline in
welfare, my attitude changed. Was release really in the dolphins' best
interests? We talk about animal welfare and animal well being and (although
there are a variety of definitions), mean that animals should be dealt with
humanely, that they must not be made to suffer or die unnecessarily and, that
any causes of suffering must be minimized. But the entire release process is
bound to be full of intense stresses and potential risk of mortality, higher
than the risks incurred in captivity.
I believe that we take on responsibilities for animals brought into captivity
so that, as long as they are in our care, we are responsible for maintaining
their health to the best of our abilities. In the case of release this
responsibility remains until the animal can demonstrate an ability to survive
independent of human care. This means ensuring that projects maximize the
chances of survival post release, minimize the risks and stresses encountered,
and ensure through post release monitoring that the animal is truly capable of
independence (even if this means introducing moderate stressors along the way
to help condition the animal for its new environment).
There is much public pressure at the moment for the release of cetaceans from
captivity, most notably in the case of killer whales such as Keiko of "Free
Willy" fame. While the intuitive appeal of an animal's living in the wild has
been used to encourage support for such releases, I believe that the results of
our study show just how circumspect we must be. It is not the case that an
animal's welfare is automatically increased, especially not in the early period
post-release. Unless there is virtual certainty of success (including adequate
funding and technology, selection of appropriate candidates and a careful plan
for rehabilitation and post-release monitoring) it might be best that the
animal remains in captivity.
Kelly Waples is a recent graduate of Texas A&M University where
completed her Ph.D. studying the reintroduction of bottlenose dolphins
from Atlantis Marine Park, Western Australia. She is originally from
California where she studied at University of California, Santa Cruz and
developed her enthusiasm for marine sciences and the study of dolphin
behavior. She has worked on a variety of projects involving marine
mammals at Monterey Bay, California, Vancouver Island, Canada, Kaikoura,
New Zealand and Monkey Mia, Australia. She spent 3 years in Australia
conducting her Ph.D. research. She currently lives in England.
The Rehabilitation and Release of Bottlenose Dolphins from Atlantis Marine
Park, Western Australia. N. Gales and K. Waples. 1993. Aquatic Mammals.
Vol. 19: 49-59.
Ethical Issues in the Release of Animals From Captivity. 1997. K. Waples and
C. Stagoll. Bioscience. Vol. 47: 115-121.
The Private Lives of Dolphins- Studying Behavior at Brookfield Zoo's Seven Seas
Panorama. A. Samuels. 1988. Bison, Brookfield Zoo. Vol 3(1) 23-29.
Return to the Wild...An option for Managing Atlantic Bottlenose Dolphins. R.
Brill. 1995. Soundings: Magazine of the International Animal Trainers
Association Vol. 20(3) 5-6, 19-20.
Reintroduction into the Wild as an Option for Managing Navy Marine Mammals. R.
Brill and W. A. Friedl. 1993. Technical Report 1549 for NRaD, Naval Command,
Control and Ocean Surveillance Center RDT&E Division, an Diego, CA
Reintroducing "Dolphins Into the Wild- Current Developments. J. Dineley.
1994. International Zoo News. Vol. 41(3) 13-16
Dolphin Chronicles C. Howard. 1995. Bantam Books, New York, NY.
Behind the Dolphin Smile. R. O'Barry. 1988. Alonquin Books, Chapel Hill,
Into the Blue. V. McKenna. 1992 Harper Collins Publishers, San Francisco,
The Dolphins Swim Free. 1994. M. Rogers. Kangaroo Press, Kenthurst, NSW,
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