By Stacy Owens, Susanne Melkulcok, and Jennifer Viglino

Are marine mammal life span shorter in captivity? The main mammals focused on in our presentation are Orcas, Belugas, Bottle Nose Dolphins, Seals, Sea lions, Walruses, Manatees, Polar Bears, and Sea Otters. Topics include comparison and difference between captive mammals and their wild counterparts. Statistics will be discussed and conclusions will then be observed.

Wild female Orcas have a mean life expectancy of 50.2 years. They typically give birth to their first calf at 14.9 years of age. They produce an average of 5.35 calves over a 25.2 reproductive lifespan. Female Orcas have a maximum longevity at about 80-90 years. Captive female Orcas have a mean life expectancy of 10.0 years. They give birth to their first calf at 6.3 years of age. They have a maximum longevity in captivity of about 30 years.

Wild male Orcas have a mean life expectancy of 29.2 years. They typically attain sexual maturity at 15.0 years and physical maturity at 21.0 years of age. Wild males have a maximum longevity of about 50-60 years. Captive males have a mean life expectancy of 4.6 years. They reach sexual maturity at 5.0 years of age. They have a maximum longevity in captivity of about 25 years. Just as a general note, the Orca in "Free Willy", Keiko is the oldest male Orca in captivity at 20 years of age.

The captures of Orcas began 33 years ago (1966). Sixteen Orcas had been captured and none of them are alive today. By 25 years ago (1977), fifty Orcas had been captured and only two of those are alive today. By twenty years ago(1979), 65 Orcas have been caught and only three of them are alive today. Among the fifty Orcas in captivity world wide at the present time, only two are beyond their mid-twenties. They are Corkey at Sea World of California, and Lolita at the Miami Sea Aquarium.

Bacterial pneumonia is the most common cause of death for Captive Orcas. Viral and fungal infections get on the spleen and lymph nodes leading to pneumonia getting into the lungs. Orcas also die in captivity at early ages due to stomach ulcers, skin disease, tumors, heart disease, and respiratory disorders.

In the wild, Beluga Whales face a number of environmental threats. Industrial run-off in the St. Lawrence river has resulted in high levels of PCB’s, heavy metals, and other toxins in the water. The toxins enter the food chain through single celled organisms and become concentrated in the bodies of the Belugas. The deaths and stranding of many Belugas are thought to be linked to these toxins. In captivity, Belugas have advantages and disadvantages.. They get high quality medical care, constant supply of food, and freedom from predators. However in captivity, Belugas do not grow to average size, and experience many unsuccessful pregnancies. Their cause of death can be due to a variety of factors such as skin disease, heart disease, and different infections.

Wild Dolphins have comparable life spans to boriginal humans, which is 30 to 45 years. The "high tech" medical practices that have helped humans reach a life span averaging 75 years, has not yet helped captive Dolphins match the life span of the wild ones. Half of the Dolphins in captivity die with in seven years. Wild Dolphins under similar harassment stress, have a mortality rate of less than 170 per year and possibly as much as 2.59 % per year. Many captivity deaths are related due to the radical spatial constriction which occurs when Dolphins are taken from the ocean and its estuaries and put in man made enclosures of captivity. Roughly half a million Dolphins die annually from the man-made causes, including water pollution in the coastal areas and the drift nets that are still used in many countries.

Pinnepeds benefit from captivity because of marine mammal centers. These center rescue, rehabilitated, and release hundred of injured , orphaned, or disoriented Seals and Sea lions. The centers main focus is to return the animal back to its natural habitat. The centers are ran by specialist in the field, and many volunteers. These volunteers are trained in animal handling techniques and husbandry.

There are two main centers in California that are helping these Seals and Sea lions. The first center is called The California Marine mammal Center, and its located a few miles north of San Francisco. It was created by Loyld Smalley in 1975. This center mainly rescues orphaned Elephant Seal and Harbor Seal pups. Most animals rescued are badly injured by severe wounds or diseases. Once an animal is determined injured or in trouble its picked up and brought to the center for rehabilitation. Upon arrival the animal is examined by a veterinarian and medical treatment is begun. If an animal dies a necropsy is performed to determine cause of death. During the necropsy tissue sample are taken from all of the major organs to be analyzed and preserved for further studies. It cost approximately Three hundred dollars to care for an animal from the time of rescue to the time of release. This figure only takes into account transportation, food medicine, and cleaning supplies. It doesn’t include the salaries, equipment, and maintenance of the facility. This center has about 65% of its patients returning to its natural environment and each year the survival rate increases.

The second marine mammal care center is located at Fort MacArthur in San Pedro California. The center is a five year old non profit center on one acre with eight fenced in pens and six pools. They look at how El Nino has affected pinnepeds, and how to keep mortality rates down in the pups. This center has treated 122 injured or disoriented Seals and Sea lions. Restoring the health of these pinnepeds can take about three months. In both of these centers the workers can not get attached to the animals because they don’t want to domesticate them. Therefor the staff must wear a huge garbage can with the bottom cut out when venturing into the pen.

Walruses are also benefited by captivity. The Aquarium for Wildlife Conservation in New York works with orphaned Walrus calves. Five orphans live in this Aquarium Nuka the oldest(15 years old) was found near the town of Barrow on the northern tip of Alaska. Tiipaq was found ten years later in the same spot as Nuka. Ayvey,Uppa, and Kulusia were orphaned as infants when their mother was killed in an annual hunt in 1994. It is said that if the mother dies the orphan can not be fed and the baby dies. These calves were 120 pound puppies when they arrived. They needed twenty four hour care and had to be bottle fed for two years. Now the Walruses weigh nearly one thousand pounds each and eat between forty to sixty pounds of food a day. The biggest challenge was keeping these Walruses mentally stimulated because in the wild they spend their time looking for food. So to keep them occupied the keepers had to teach them to fetch and wave. Walruses have to consume a large volume of food in preparation for their search for land. When the ice starts melting in the summer, females energy is important for calving because a pregnancy last for 15 months. Females deliver one calf every two years. Just before the seasonal migration Walruses will travel thousands of miles to their summer destination and the calves must stay with their mother to nurse. This is when calves become orphaned.

Yes it is true Walruses are killing themselves off an Alaskan cliff at Maggie Beach. This is the third consecutive year this has happened and scientist do not know why. Even the Eskimos are puzzled. In 1994: 42 died, 1995: 17 died and now in 1996:70 died. In 1996 to researchers saw the migration and intervened by turning 150 Walruses back. Two theories for this incident exist. First one is that sand dunes that once blocked access to the cliff are no longer there due to the Walruses and storms. The second one is that once the Walruses are at the top they are to large to turn around and fall off the cliff. Then the rest of them follow. A barrier could be built to prevent this from happening, but there has been too many debates about interfering with natural selection.

Manatees life span in the wild or captivity has not yet been determined. The method of aging marine mammals can not be applied to the Manatee due to their unique tooth replacement. Therefor the cementum layers on the tooth can not be relied on as accurate whole life span. So scientist have made estimates of life span to be 50-60 years. A Manatee in captivity has already reached the age of 42 years old. The hypothesis that they benefit in captivity can be shown by comparing the amount of deaths in the wild and their causes. Chart one was a graph that indicated an increase in death rate each year. Graph two gave a break down of causes of death, making a majority of the chart human related. This indicates as captivity being a better environment for them to live in.

Polar Bears can live from twenty to thirty years in the wild, but only a small portion live past eighteen years.(Sterling 1988) The oldest Known Polar Bear to live in the wild was from the Arctic and was thirty two years old. The oldest Known Bear in a zoo was forty one years old.(Sterling 1988) This large difference in life span can be due to the risks they face in the wild.

In the wild even through the bears are near the top of the food web they still face many risks. Male Polar Bears are at risk to each other. Cubs are at risk from male Polar Bears and wolves.

Humans also pose a threat because of hunting and pollution. The oil spills have caused death by saturating their fur so they loose insulation properties and die from hypothermia.

Captivity can be detrimental to them for behavior reasons. An example of this is Gus the bear in the New York City Zoo. Gus is an eight year old Polar Bear who was born in captivity. He was showing signs of compulsive behavior in repetitive swimming for hours on end, and not eating well. The zoo hired animal behaviorist specialist Tim Desmond (who trained the whale in Free Willy) to evaluate the animal. He diagnosed the Bear with not getting all the behavioral opportunities that were needed. This meant the bear was bored. Tim Desmond then designed activities like hiding the bears food and toys to stimulate him. This therapy will have to continue for the rest of the bears life.

Sea Otters also seem to benefit from captivity. Their average life span in the wild is about ten years, but only 2% of the population live that long. The highest age in captivity was documented at 23 years. This like the Polar bear can be due to lack of risk from the wild. In the wild Sea Otters are at risk from predation of the white shark, and the pups from the Bald Eagle.

Humans are also a big threat with hunting and pollution.

The benefit for the marine mammal is specie dependent, and what type of captivity the mammal is experiencing. Two main types of captivity were discussed, one for research / entertainment, and the second one being hospitals. The research / entertainment provide more information about life spans because of the long time span that the mammals are kept there. The animal hospitals are usually temporary facilities with the animals being returned to the wild.

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