ORLANDO, Fla. (AP) -- Since the release of a highly-critical documentary last year, Sea World Parks and Entertainment Inc. has been in the crosshairs of animal rights activists who say its killer whales suffer in captivity. But an analysis of federal data shows that annual survival rates for marine mammals at, Sea World's three parks are at or near the top of all U.S. parks and aquariums. Sea World's survival rates for bottlenose dolphins and California sea lions actually exceed estimates for those in the wild.
Killer whales born in captivity at Sea World parks live about as long as their counterparts in the wild, according to an Associated Press analysis of five decades of data from the federal Marine Mammal Inventory Report. However, the life expectancy of all Sea World's orcas, including those captured in the oceans, is lower than of those living in the wild.
Sea World's survival rates have steadily improved over the past five decades.
"We do a lot of self-critiquing of who is doing what, how," said Todd Robeck, vice president of reproductive research at Sea World Parks and Entertainment Inc., which is the largest holder of marine mammals in the United States. "How are you handling food? How are you handling your moms and calves? What is the medical care?"
Critics say that regardless of survival rates, keeping intelligent marine mammals in captivity is inhumane and detrimental to their well-being.
Last year's documentary, "Blackfish," explored what may have driven a killer whale named Tilikum to kill veteran Sea World trainer Dawn Brancheau in 2010. The documentary argued that killer whales in captivity become more aggressive to humans and each other.
Several entertainers, including Wille Nelson, Heart and Trisha Yearwood, pulled out of planned performances at Sea World parks, and opponents have been protesting regularly outside Sea World's Orlando park, holding signs reading "All animals deserve freedom" and "Sea World: let orcas out of prison."
"Sea World continues to exploit these complex and very socially interactive animals," said Bryan Wilson, a coordinator for the Animal Rights Foundation of Florida, during a recent protest.
AP calculated survival rates for killer whales, bottlenose dolphins, California sea lions and beluga whales -- among the most common marine mammals in captivity -- at more than 170 U.S. parks and aquariums. Animals younger than a year old weren't included because of the difficulty of making comparisons in the wild at that age.
Life expectancy averages were calculated from the survival rates. The analysis revealed:
-- The average life expectancy for captive killer whales was almost 28 years, compared to an estimated 47 years for the wild population, using often-cited populations of wild killer whales off British Columbia and Washington state. It was also 28 years for all orcas at Sea World parks, but 46 years for Sea World killer whales born in captivity.
-- Captive bottlenose dolphins had an average life expectancy of 24 years, and it was almost 45 years for Sea World dolphins. The average life expectancy in the wild is 25 years, using an often- cited population of bottlenose dolphins off the Sarasota coast.
-- California sea lions had an average life expectancy of 20 years at parks and aquariums and more than 31 years at Sea World parks. Estimates in the wild put average life expectancy at more than 17 years.
-- The average life expectancy for beluga whales was 19.5 years in captivity, and 24.5 years at Sea World parks. Average life expectancy estimates in the wild ranged widely, from 11.5 years to 62 years.
Medical care for marine mammals at parks and aquariums has improved dramatically over the decades, and that has contributed to improved survival rates.
Decades ago, an evaluation of a marine mammal at a Sea World park might require a pool to be drained for an X-ray or the animal to be restrained. No longer. Through behavioral training, and bribes of herring and salmon, the marine mammals at Sea World parks have learned to give breath, urine and blood samples on cue. Dolphins are trained to keep their heads out of the water so endoscopes can be passed into the stomach for a look. An elaborate laboratory on Sea World grounds allow samples to be evaluated immediately.
On a recent day at Sea World's Orlando park, killer whales Melia and Kayla slid up on their sides on shallow water platform in a pool and urinated on command into cups held by trainers. In another pool, a pregnant dolphin named Bossa was given an ultrasound.