Kayce Cover's physicist father wanted her to be an electrical engineer when she grew up, "but I saw Flipper when I was nine, and that was it." Now grown up and graduated from the University of California at San Diego, Kayce has the dream job of any kid who flipped over Flipper: She's the keeper- leader of seals and sea lions at the National Zoo. Dream job if you don't mind that your "office" smells of fish -- 111 pounds of herring and butterfish that are shared by the six California sea lions and five gray seals every day.

"Sea lions have external ears, and they're more terrestrial," she explains, taking buckets of fish out of the freezer in back of the sea lion pool. "Seals are more marine- adapted -- they spend more time at sea. Sea lions also have a definite dominance system. They're more manageable. It's like the difference between dogs and cats."

Kayce has managed to train both seals and sea lions, however, and every day at feeding time she demonstrates training techniques to the public. Sea lions get fed first, and as Kayce and two volunteer assistants walk out on the fake rocks they call "the beach," the sea lions swim in fast, excited circles, then approach the trainer.

"Hi, Norman," she greets the 425-pound pasha of the five-female harem. "Oh, thank you, Maureen, you brought me a leaf."

Zoo seals aren't trained to perform with beach balls like circus seals. But they do receive basic training "so we can take the best possible care of them," explains Cover. For instance, they have to learn basic obedience so that they can be moved when necessary and examined by a veterinarian. They also have to learn to retrieve objects. This is important because people throw junk in the pools and the keepers want the seals to bring them the objects without eating them.

While Norman is off cavorting with his current favorite, Pearl, a very pretty sea lion with big brown eyes whom he prefers to Maureen despite the latter's obvious devotion to him and Pearl's indifference, Kayce puts Maureen through the paces of a routine veterinary exam.

"Flipper? Flipper? She has to give you her flipper. If you have to fight her for it, it doesn't count," she explains to the human audience. When Maureen has presented flippers properly, she gets a fish. And still another for retrieving a Frisbee and still another for jumping and turning at the same time.

"Notice how this animal works solely for my affection," Cover deadpans. "She's looking over her shoulder to see what Norman's doing. She may be afraid that Norman's going to take it unkindly that she gets a fish and he doesn't."

Norman soon gets his turn to shine and eat fish, however. On a voice-and-hand command from Cover, he jumps up on a big rock, demonstrating how sea lions get out of the surf.

"Everybody clap for Norman," urges the trainer. "He's very vain. When he's fully grown, at 10, he'll weigh about 800 pounds, and that crest on his head will look like a baseball. He's six now. He's about twice as big as the females and eats twice as much. How do we tell them all apart? Like humans, they have distinct features, but not different clothes and hairdos, of course."

Next door, in the seal pool, it's even easier to tell the residents apart. You can't miss Keltie, because she's always chanting a siren-like hum. The smallest seal is baby Chandria, born 18 months ago to Gunar, the big, burly male, and Selkie, who has a scar on her face from the time that Gunar broke her nose. Despite this, the keepers think Selkie may be pregnant again. If so, she'll give birth in December. Pregnant or not, Selkie -- whose name derives from mythical half-seal, half-human creatures -- needs to lose weight, and Cover leads her through a tunnel and over the rocks of the beach.

"Training is a good means of keeping animals active," she explains, rewarding Selkie with a fish. "We invent little games. I get them to help me drag a net across the pool. This isn't only fun, but it keeps the pool clean. Animals really like training. Even if they're uncooperative, they still get their full amount of food every day. We reward them with fun. Norman really likes to slide, for instance, and Maureen loves to retrieve. When they do something well that they don't really enjoy -- like the veterinary exam -- we reward them with something they really like to do. Ready, guys? Want to swim?"

That's something they all like to do. Everybody into the pool. SEEING SEA LIONS AND SEALS -- Training demonstrations are given at the sea lion and seal pools of the National Zoo daily at 5 o'clock. There will be no demonstration Friday, September 30. Beginning October 1, the demonstration will take place at 1:30. Cover answers questions from the audience after each demonstration.