Greed and Profit

Seaworld rakes in over 1.4 billion from all their marine mammal parks, Florida politicians get over a half million from Disney alone.
Many cities have large investments in aquariums such as Baltimore where the National Aquarium is the center piece of their urban renewal of the inner harbor area, it has an annual attendance of 1.6 million .
The Georgia Aquarium cost around 300 million to build, between 2006 and 2009 they had over ten million visitors, at $26 per adult, $21.50 for Seniors, and $19.50 for Children .

Killer whales in the wild can live on the average live 50 to 60 years and can live up to 90 years.

By far, the largest holder of killer whales is Sea World, Inc.
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.