Aquatic mammals in zoos are not a distinct zoological group, but might
include the 'real' aquatic mammals, whales and dolphins, as well as 'swimming mammals'
like seals and sealions, otters, and rodents such as beavers, coypus, and capybaras. Other
mammals that might sometimes be thought of aquatic could include hippopotamuses, tapirs,
and even water buffalos, or polar bears. Clearly there are difficulties in generalising
about a group of animals this diverse.
Dolphins and whales
Dolphins and whales are a group of animals that attract a great deal of
controversy whenever they are kept in zoos. In recent years. Large Oceanaria in the
United States, like the ones in San Diego and Miami have built their successes solely upon
the huge drawing power of animals like the Orca - the so called 'killer whale'. In
Britain nearly every collection that once kept dolphins, like Whipsnade, Knowsley,
Woburn and the West Midland Safari Park have all relinquished their exhibits.
Conservationists object to the principle of keeping animals which show very little chance
of breeding in small pools, and which often involve hazards to the animals in capture from
the wild. The severest critics of dolphinaria in recent years have been organisations like
Greenpeace and the Whale and Dolphin Conservation Society. They have pointed out that the
life expectancy of captive dolphins is less than seven years, compared to thirty years or
more in the wild. They draw attention to the dramatic difference between the freedom and
space of the open seas, and the cramped limitations of a tiled pool. Dolphins and whales
live in a sonic environment, communicating and navigating with clicks and whistles and
echo-location. What a harsh and sterile and featureless environment the best of zoo pools
must be to such an animal when compared to the open oceans. Dolphins and whales are
intelligent, sensitive, social animals. Hundreds of them are still captured from the seas
every year for Sea Worlds and Dolphinaria all around the world, and the survival rate of
captured dolphins is pitifully low. The most unfortunate asset that the dolphin possesses,
the conservationists say, is its smile. It is not a human smile, despite its appearance,
and it creates the impression of a happy, contented animal. The truth may be very
Zoos with dolphins assert that their animals are ambassadors for their
species in the wild, and few people can fail to be moved by the almost unbelievable skill
and intelligence of dolphins in a dolphin show. Not everyone is convinced, however, and
controversy about the morality or otherwise of keeping captive dolphins is bound to
continue. Some European and American zoos have succeeded in breeding and rearing dolphins
in large pools.
Seals and sealions
With the move away from dolphins, some zoos and oceanaria have brought
in sealions to fill their empty pools. Like dolphins sealions can be trained to perform
for the crowds. Two points of view seem to be held about the best way to keep and display
sealions. The more traditional zoos believe that both sealions and visitors prefer regular
circus shows - balancing balls, performing handstands, and barking for fish. They will
argue that the sealions clearly enjoy the shows, and can sometimes point to breeding
successes to justify their attitude.
Other zoos prefer untrained sealions, in family groups. Zoos that
have taken this approach, like Chester Zoo in
England, also end up with an enormously entertaining exhibit, particularly if the
sealions have a large, deep, landscaped pool. The attraction at these zoos comes from the
natural activity and boisterous interaction of the sealions. Family groups in large pools
can be used at feeding time, to give an entertaining display, and this type of 'sealion
encounter' can often teach us more about the biology and behaviour of the animals than any
number of circus tricks will ever do.
Perhaps, however, each school of thought could learn from the other. A
live commentary at feeding time could enhance the experience at some zoos, while zoos that
keep performing sealions could benefit from enlarged pools, and natural beaches. There are
around fifty California sealions and a dozen Patagonian sealions in British Zoos. Only one
or two of each species are born and reared every year, probably not enough to maintain the
current zoo population. To breed sealions successfully a zoo really needs a quiet breeding
beach, and offshow pens with some means of separating the adults. Good zoos are now
cooperating in a management scheme for sealions which aims to improve the breeding
successes by the sensible grouping of animals at good facilities.
Mammals and birds that swim have the potential to be exciting, dynamic, zoo exhibits.
But although many zoos have underwater viewing for their penguin pools, this idea is not
often copied for their swimming mammals. In fact, many zoo enclosures rather under-value
the swimming behaviour of animals like tapirs, capybaras, or even talapoin monkeys.
Oceanopolis in Brest on the Atlantic coast of France has huge tanks for harbour seals with
real wave action and underwater viewing. San Diego Zoo has crystal clear water for viewing
the hippos. Large bodies of water in an enclosure can be difficult and often expensive to
maintain in a clean and safe way, and many zoos tackle this problem in a rather
half-hearted way. Pools are often either too small, or make very little provision for