In Monterey Bay, a marine biologist tracks a school of more than 500 Pacific white-sided dolphins that are working together to herd their prey into a ball for an easy lunch.
At the same time, in a tank at the Long Marine Laboratory of the University of California at Santa Cruz, Calif., two Atlantic bottlenose dolphins go through their paces, performing a task in exchange for a couple of fish.The contrast between the two worlds - wild and captive - has become a controversial question that plagues marine researchers.
"Among scientists we never talk about it," said Daniela Feinholz, president of the Pacific Cetacean Group, "because you never know how the other person is going to feel about it."
Feinholz, who works "temp" jobs in order to support her research on marine mammals and her studies toward a master's degree at the Moss Landing Marine Labs, said the topic is touchy.
"A lot of people have very strong feelings about it," she said. "It becomes personal and has nothing to do with science a lot of times, but has to do with how you feel about animals."
Feinholz has been studying a transient population of bottlenose dolphins in Monterey Bay for five years. She can identify more than 100 individual dolphins.
Studying the only two captive dolphins in the Monterey Bay area is Terri Williams, an assistant professor of biology at the University of California at Santa Cruz. She is studying the two bottlenose dolphins at Long Marine Lab, observing their physiology and swimming mechanics to determine how much energy they require to swim and dive.
"As much as I'd love to say we can observe animals in the wild," Williams said, "the really sad truth is we barely know anything about the basic biology of the animals. If you go into the biology books, we know a lot about rats, but we barely know the heart rate of dolphins. And if we don't learn it now, we're going to watch the population decline and eventually we're going to lose them."
The two bottlenose dolphins at Long Marine Lab are both males. Puka, 9, and Primo, 14, are on loan from the Navy Oceans Systems Center in San Diego.
"These animals are raring to go every morning," Williams said.
Members of animals rights' groups sometimes clamor for the dolphins to be released, Williams said, but "the researchers would say, `we've done thousands of releases and they keep coming back."
Once animals have been trained, she said, they usually return even when given the chance to escape. She worked with other trained dolphins at Kaneohe Bay in Hawaii that would sometimes go off to visit other dolphin groups, then return and wait for humans to open their sea pens.
"I don't know if you would classify that as an escape," she said. "They were able to leave and didn't."
One compromise solution to putting dolphins into lifelong captivity was tried at Long Marine Lab a few years ago.
Known as "dolphin sabbatical," the concept was originated by biologist Ken Norris, a retired professor from UC-Santa Cruz who set up the Long Marine Lab and is considered the guru of dolphin research.
"What we learned about dolphins we learned largely from captivity," Norris said. "Now that we learned what marvelous animals they are, people want to turn them loose again. That would extinguish the opportunity to learn more."
Norris devised the plan to capture two bottlenose dolphins and keep them in captivity for 18 months to two years, then carefully release them back into the area where they had been captured and track them to see how they readjusted.
While the dolphins, Echo and Misha, successfully returned to their home environment off the coast of Florida, Norris concluded that the "sabbatical" was too hard on the animals.
But, he said, "I'm still not sure whether society will let us learn more and I'm sad about that, because it's absolutely true that there's all sorts of things you can learn in a captive situation that you just can't at sea."
Norris began doing dolphin research in the 1940s, when the first colony was kept in Florida and little was known about dolphins.
As scientists learned about dolphins' special characteristics, he said, the marine mammals "began to become icons in the struggle over the earth."
In selecting animals for his "dolphin sabbatical," Norris said, he chose young males because they are typically wanderers and "the other population would just think, `George and Charley have wandered off just like the rest of them."'
Carol Howard, a doctoral candidate who studied the two young males selected for the sabbatical, said that for Echo and Misha, "it must have been like being abducted by aliens."
"It must have been so strange for them," she said. "I've tried to put myself in their position."
About 300 to 350 dolphins are in captivity in the U.S., Howard said. It is believed that is enough to provide enough genetic diversity for breeding in captivity.
"At this point the captive-born is the ideal solution," she said. "But I don't think they are good candidates for release."
A voluntary moratorium on capturing dolphins has been in effect for several years in this country, she said, as well as a moratorium on catching killer whales.
When Hurricane Andrew hit the Florida coast, she said, dolphin handlers opened all the pens so the dolphins could escape to safety. All but one, she said, returned on their own.
At Long Marine Lab, Howard was doing echolocation studies on the dolphins, trying to understand how dolphins "look" at the world around them.
"I have mixed feelings myself about having any kinds of animals in captivity," she said. "It was hard for me to see them in captivity. On the other hand, I think it's necessary. We need to get to know them."
The biggest plus associated with having dolphins in captivity, said Nancy Black, who works for the Oceanic Society is the possibility of educating the public that several species are in danger of extinction.
"There are fewer than 100 Chinese river dolphins left," she said. "They are going to be gone within 10 to 20 years if we don't capture some and put them in a reserve."