The welfare of marine mammals in captivity

The welfare of marine mammals in captivity.
David Blyde
Firstly I should provide a detailed work history in order to justify my discourse on this
subject. I began working in zoos in 1986 at Taronga Zoo. I was first employed as a
veterinary intern. I remained at Taronga Zoo until early 1989 when I secured a job as
veterinarian at Western Plains Zoo (WPZ), Dubbo, New South Wales. I worked as a
veterinarian at WPZ for 13 years. During this time I attended many national and
international veterinary conferences. I taught both the zookeeping certificate course at
TAFE and the post-graduate Captive Animal Management course at Charles Sturt
University. I left WPZ in 2001 and began working at Sea World, Gold Coast as the
veterinarian. I have visited zoos in Asia, Europe, North America, Africa and Australasia.
I have undertaken many animal welfare investigations for the RSPCA on zoos and game
farms. I am a member of the Australasian College of Veterinary Scientists in Zoo Animal
Medicine and am an examiner for this same body for Zoo Animal Medicine and
Medicine of Australasian Species.
The welfare of animals in captivity has been a contentious issue for as long as zoos have
been in existence. The relevance of zoos to modern society has been debated in many
forums but the fact that approximately 600 million people visit zoos and aquaria annually
(The World Zoo and Aquarium Conservation Strategy 2005) seems to support their
continued existence and relevance in our modern society. The culture of Australian
society is not as supportive of zoos as the American or European culture but nevertheless
zoos are still a popular entertainment venue for Australians. It should be remembered that
all zoological institutions are businesses and as such have financial constraints when
animal exhibits and management are concerned. There will therefore always have to be
compromises made when discussing the welfare of animals in the captive environment.
Many different species of animals are held in zoos and aquaria. Some adapt to captive
situations quite well whilst others do not. Some species are easy to keep physically
healthy but difficult to keep psychologically healthy e.g. Polar Bears. Some species are
just not suited for the captive environment e.g. European Hares. Some species survive
well but if not kept in appropriate conditions develop health problems e.g. Asiatic
We should be mindful however of how we interpret the welfare of animals in zoos and
aquaria. We need to be careful that we do not anthropomorphize about their situation.
Anthropomorphism is defined by the Macquarie Dictionary as “the ascribing of human
form or attributes to beings or things not human”. For instance some species e.g. Polar
Bears are solitary animals and may be better off being exhibited singularly rather than in
pairs or groups. However, the first thing the public will criticize is the fact that the “poor
bear is lonely and needs company”, which may be far from the facts. The ability to
determine whether or not an animal is “happy” in captivity can be very objective and
often not based on fact.
Assessment of animal welfare for domestic animals has been investigated. In 1965, when
the British government first reviewed the welfare of farm animals they proposed that all
farm animals should have the freedom to “stand up, lie down, turn around, groom
themselves and stretch their limbs”. These minimal standards became known as “the five
freedoms”. These standards have been modified over the years and the five freedoms now
1. Freedom from thirst, hunger and malnutrition – by ready access to fresh water and
a diet to maintain full health and vigor.
2. Freedom from discomfort – by providing a suitable environment including shelter
and a comfortable resting area.
3. Freedom from pain, injury and disease – by prevention or rapid diagnosis and
4. Freedom to express normal behaviour – by providing sufficient space, proper
facilities and company of the animals own kind.
5. Freedom from fear and distress – by ensuring conditions that avoid mental
There are a number of fundamental issues which need to be considered when evaluating
the appropriate welfare of animals in captivity and these are similar to those for domestic
livestock. These issues include diet, social structure, appropriate veterinary care, exhibit
size and the ability of the animals to exhibit normal behaviours. In essence, zoos and
aquaria need to provide the appropriate environment for the animal’s behavioural and
physiological needs.
In addition to these fundamental issues when we are dealing with marine mammals in
captivity, we need to consider water quality issues. Because marine mammals spend a
great deal of time in the water, appropriate water quality is critical for their health and
The objective assessment of animal welfare for captive animals is a contentious issue as
different people have different ideas about how animals should be cared for and whether
they are “happy” or not. It is made more difficult by not having any objective criteria to
assess it against.
Appropriate diet is vital to the welfare of captive animals. This includes the necessary
caloric requirements for the animals, any special nutritional needs and the appropriate
levels of vitamins and minerals in the diet. The ration should be palatable and presented
in the correct fashion. In addition, the behavioural and environmental enrichment
component that the diet provides to the animal should be considered. For instance carcase
feeds provide more behavioural enrichment to carnivores than piece-meal food.
Social structure
The social structure of animals in captivity is vitally important for their ongoing welfare.
In order to satisfy this social structure the normal biology of the species in question must
be known. For instance Polar Bears are generally solitary animals except when males and
females come together at breeding time and when a mother is rearing her cubs. On the
other hand cetaceans are generally gregarious and live in small pods of females and their
offspring. Males tend to form bachelor groups or pairs. Seals live in colonies but large
mature breeding males stake out their own territories and do not interact with other males
except to compete for territories and breeding mates.
Appropriate veterinary care
All animals in captivity should have access to professional veterinary care should they
become sick or injured. Veterinarians should be appropriately trained to immobilize and
treat these animals appropriately. Appropriate equipment and facilities should be
available to diagnose and treat disease conditions. Pain and suffering should be
minimized. In addition, a preventative medical program should be developed and
implemented to prevent disease from occurring in captive animals. This preventative
medical program should consider such things as vaccinating for common specific
diseases, drenching animals for internal parasites on regular basis and reproductive
Exhibit size and facilities
The exhibit should be large enough for the animals to exhibit natural behaviours. It
should also contain appropriate furniture for the species. For example Orang utans should
have the ability to climb, brachiate and nest in elevated areas. Seals should have the
ability to swim, dive and porpoise. Exhibits should provide shelter from the elements.
Shade is vitally important when exhibiting seals to prevent solar damage to their eyes.
Exhibits should also provide a safe barrier between the public and the animals. They
should be designed in such a way that they can be easily cleaned. They should contain a
restraint facility that assists animal managers in restraining the animals in a safe and
effective manner.
Animal exhibit sizes and facilities are prescribed in various regulations such as the
Exhibited Animal Protection Act (EAPA) guidelines in New South Wales and the Code
of Practice for the exhibition of exotic animals in Queensland Zoos, Parks and Aquaria
developed by the Department of Natural Resources, Mines and Water. The peak
zoological body in Australia – Australasian Regional Association of Zoological Parks
and Aquaria (ARAZPA) - is currently developing standards for self-accreditation of zoos
and aquaria.
Many animals in zoos develop inappropriate behaviours which are generally termed
stereotypic behaviours. These stereotypic behaviours develop because the animals are not
able to undertake day to day activities that they would normally undertake in the wild.
They do not have to hunt for food or avoid predators. They become “bored” and develop
stereotypic behavious. Other stereotypic behaviours develop because the animal is
stressed by an exhibit mate or exhibited in less than optimal environments. Animals in
captivity therefore require environmental or bevahioural enrichment. This enrichment can
take the form of hiding food items, carcase feeds for carnivores, multi-species exhibits to
increase interactions or training. An enrichment program should be developed and
Water quality
Appropriate water quality is essential for the welfare of marine mammals in captivity.
Inadequate water quality can lead to eye problems, skin problems, infections and death.
Ideally, animals that live in the marine environment should be kept or have access to
filtered, disinfected natural sea water. Artificial salt water is adequate if the constituents
in the water are checked regularly. Water quality includes the following parameters – pH,
salinity, temperature, alkalinity, phosphate levels and bacterial levels. Table 1 lists the
parameters and the ranges that these parameters should fall within.
Bacterial counts
Accepted Range
7.8 – 8.5
1.028 – 1.037
< 100 ppm
< 3.5 mg/L
< 1.5 mg/L
15°C - 30°C
< 5 CFU’s per 100 ml
Objective measurement of animal welfare in marine mammals in captivity
The measurement of welfare for animals in captivity is a difficult and contentious issue.
Some of the factors that need to be considered when evaluating animal welfare include
health records, longevity and the presence of a well considered veterinary preventative
medical program. Other factors that should be considered include behavioural issues,
husbandry procedures, exhibit size and the presence of a well considered environmental
enrichment program. In addition animal diets, social structures and reproductive control
should be evaluated.
The welfare of marine mammals in captivity is not radically different from the welfare of
terrestrial mammals in captivity. The one outstanding difference is the importance of
water quality. Marine mammals spend a great deal of their time in the water and therefore
water quality is extremely important in satisfying a high level of animal welfare. Animal
welfare issues in zoos and aquaria are always somewhat compromised by the financial
limitations of the institutions. Animal welfare in zoos and aquaria can and should be
measured objectively using the parameters mentioned previously e.g. animal longevity,
animal health records and the presence of a preventative medical and enrichment
program. Other measurements should include compliance to exhibit regulations, a
breeding program and adherence to “best practice” animal husbandry. Records should be
kept, evaluated regularly and changes made according to these records. An objective
measure of animal welfare for captive animals in zoos and aquaria would make the
assessment of animal welfare much easier.
The World Zoo and Aquarium Conservation Strategy: Building a future for wildlife
(2005). Ed PJS Olney, WAZA Executive Office, Berne, Switzerland.