By Bob McDonald, host of the CBC science radio program Quirks & Quarks.

The tragedy at Sea World in Florida, where trainer Dawn Brancheau was drowned by an Orca named Tilikum, has re-ignited the debate over the value of holding these large wild predators in captivity. Sadly, the whale was doing what it does naturally in the wild, but the idea of returning it to the wild may not be the best option for the whale.

To see killer whales in the wild is a privilege and if you are on a boat, usually involves a chase. Even if you know where the whales are, you have to search and then follow at speed because the animals are in constant motion.  

Along the west coast of B.C., killer whales can wander for hundreds, even thousands of kilometres, swimming at speeds exceeding 50 km/h, one of the fastest marine mammals.  Tall dorsal fins slice the water, barely making a wake while plumes of spray mark their deep breaths at the surface. A hydrophone, hung over the side of the boat, records the clicks and squeals as the highly social animals communicate in their own musical language.

Is it any wonder that an intelligent, free-ranging animal - taken out of the wide expanse of the sea and confined to a tank only a few times its body length, filled with chemically treated water, cut off from its family and asked to perform three shows a day - might get a little irritable once in a while?

Trainers will tell you that while killer whales are incredible animals, they have moods just like children, and every now and then, they throw temper tantrums. The behaviour that led to the tragic death of trainer Dawn Brancheau is similar to a hunting technique used by the whales to pluck seals off rocks, beaches and ice flows. They're taught to do it by their parents.

Sea World has decided not to destroy Tilikum, who is the largest whale in captivity, nor have they decided to send him back to the wild. That would likely be a death sentence as well.  An animal that has been captive for most of its life is not equipped, physically or socially, to return to the sea.

When you look at photographs of Tilikum, or most captive killer whales, their dorsal fins are flopped over and lay across the back. That's because the whale doesn't swim as much or as fast in the tank as it does at sea, so the fin doesn't have to act as a stabilizer.  The lower level of activity likely means the animal's swimming muscles would also be weaker than its wild counterparts, making it less able to cover the long distances.

After the movie Free Willy was released, there was great public pressure to release Keiko, the whale that was featured in the film. After millions of dollars and years of trying to adapt the animal to wild conditions, Keiko did manage to spend a year at sea, covering more than a thousand kilometres. But eventually, the whale ended up in a fjord in Norway, following boats and becoming a tourist attraction. It did not assimilate with other killer whales because it accepted humans as its family. Keiko soon died of pneumonia.

Here in Canada, Luna, a young whale that became separated from its pod, also became friendly with people. It was killed by a propeller from a boat in the harbour where it was hanging out.

That places Tilikum and the owners of Sea World in a difficult situation. With three deaths on his head, the whale is not trusted in captivity and has little chance of survival in the wild.

Operators of aquariums say the captive whales expose millions of people to these animals, raising awareness and providing a powerful educational tool. This is true.

Many whales today were born in captivity, so they are already adapted to conditions in a tank. Let them be the public animals. This fatal incident in Florida is an opportunity to finally stop the practice of taking wild animals from their natural habitat and let them live with their real families.

If you want to see a wild whale, go whale watching.