Yulka, a beluga whale, swims at the Oceanografic in Valencia August 11, 2006.
A Japanese researcher says he has taught a beluga whale to "talk" by using sounds to identify three different objects, offering hope that humans may one day be able to hold conversations with sea mammals.
Nack, a whale at the Kamogawa Sea World marine park near Tokyo, emits a short, high-pitched sound when he sees a swimming fin, a long, high-pitched sound when he sees goggles and a short, low-pitched sound when he sees a bucket.
He correctly chooses the right object when the three sounds are played back to him.
Tokai University professor Tsukasa Murayama started training Nack after he became dissatisfied with hand-signals currently used to communicate with dolphins and whales.
"I have always wanted to talk to whales, and as I thought more and more about it, I realized that they already communicated through sound," he told reporters.
"That is why I thought I could train them to name certain items using sounds they already make."
Murayama said he hoped one day to train whales to express their feelings in a way that humans could understand.
"It would be great if they would be able to tell us not only of their likes and dislikes but also their desires, like whether they are hungry or if their backs are itchy. So the next step would be to teach them a wider range of vocabulary," he added.
However, to expand communication, Murayama said humans needed to use special equipment to produce and detect ultrasonic sounds.
"At the moment we are only using limited sounds audible for us among their wide sound range. But whales communicate better through ultrasonic sounds than through human-audible sounds, especially underwater," he explained.
Japan has come under growing pressure from international environmental groups to put an end to whale hunts, which they say are cruel and violate a 1986 global moratorium on commercial whaling.
Japan considers whaling to be a cultural tradition which it says it only undertakes for scientific research.
Meat from the hunts is available in Japanese supermarkets and restaurants, although appetite for what is now a delicacy is fading.