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News 29 Oct 07
Captive marine mammals lead short, miserable lives
By John M. Crisp
Scripps Howard News Service
Here in South Texas, marine-mammal mortality was in the news during the past few weeks. On Sept. 21, Cobie, a 15-year-old bottlenose dolphin housed at the Texas State Aquarium in Corpus Christi, succumbed to a lung condition that had plagued him all summer. The director of the aquarium says that Cobie was a "wonderful ambassador for his aquatic brethren."
On Oct. 17, Taku, a so-called killer whale, died of pneumonia at Sea World in San Antonio. He was 14 years old.
In general, vegetarians have a better claim to the animal-rights moral high ground than do meat-eaters like most of us, but there's still something disturbing about the premature deaths of these captive mammals.
Marine mammals are elusive in the wild, and scientists have a difficult time determining their normal life expectancies, as compared to those of terrestrial animals. A range of estimates is available, but this one by an office of the National Oceanic and Atmospheric Administration (NOAA) is typical: "Life expectancy for wild female killer whales is approximately 50 years, with maximum longevity estimated at 80-90 years. Male killer whales typically live for about 30 years, with maximum longevity estimated at 50-60 years."
A maximum longevity of 90 years could be a stretch, but the other numbers sound feasible, especially if we accept the generally acknowledged connection between life expectancy and animal size: a mayfly may live a day or two and a mouse for several years, but once nature invests the time and resources that it takes to produce a 22,000-pound, seagoing beast, the expectation is that it will survive for more than a decade or two.
But not necessarily at theme parks and aquariums. These institutions tend to lowball non-captive life expectancies. But considerable evidence suggests that the confines of a typical Sea World display tank isn't the healthiest environment for an animal designed to swim 50 to 100 miles per day, eat fresh fish and live in a complex social structure.
Here's some admittedly anecdotal evidence: NOAA maintains a marine-mammal inventory that includes all of the killer whales and bottlenose dolphins held in captivity around the world.
This document makes for instructive reading. By far, the largest holder of killer whales is Sea World, Inc. My copy of the NOAA report from a couple of years ago shows 62 killer whales in Sea World's inventory, of which 29 have died. Since many of Sea World's whales were taken from the wild, information about birth dates is sketchy. But of the four dead animals that show an actual or estimated birth date, one lived a month, one lived 2 years, one lived 11 years and one, a female, lived 23 years, or about half of her estimated life expectancy in the wild.
Another 12 whales show only a captivity date and a death date, with life spans in captivity that range from 1 year to 19. The average for these 12 whales was about 9 years.
Causes of death are interesting, as well. Here's a sampling: severe trauma, intestinal gangrene, acute hemorrhagic pneumonia, pulmonary abscession, chronic kidney disease, chronic cardiovascular failure, septicemia, influenza, necrosis of cerebrum. And so on. Only one is said to have died of "old age," though this attribution is dubious, since his birth date is unknown.
All in all, the Marine Mammal Inventory Report is a gruesome chronicle of killer whales' short lives and their deaths by exotic diseases. And the story is about the same for bottlenose dolphins, as well.
Proponents of marine-mammal exhibitions sometimes argue that captive dolphins and killer whales lead comfortable, pampered lives, free from the dangers of the open ocean. Human companionship and veterinary care are provided. Dinner arrives on schedule every day in a bucket, with snacks thrown in for good performance.
But this line of reasoning is singularly unconvincing. I suspect that the bottlenose dolphin's built-in, goofy grin implies he's having a better time doing his tricks than he really is. Like us, marine mammals are serious, intelligent creatures whose existence makes sense only in the natural habit in which they evolved.
You don't have to commit much anthropomorphization to believe that these creatures lead confined, miserable lives that are, in many cases, mercifully short.
(John M. Crisp teaches in the English Department at Del Mar College in Corpus Christi, Texas. E-mail him at jcrisp(at)delmar.edu.)
Related articles on dolphins, whales, other cetaceans and large fishes.
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