Science and Technology for Canadians

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Summary

In 1973, Dr. Michael Bigg, of the Pacific Biological Station, revolutionized the field study of killer whales through the innovative technique of photographic identification of individuals using the natural markings (unique patterns of nicks and scars) on the dorsal fin and the grey "saddle" patch at the base of the fin. Dr. Bigg's work was the foundation on which much further study on killer whales is based today.

Transcript of Video

Jay Ingram
If you've seen one, you've seen them all. To the untrained eye, one killer whale might seem awfully similar to the next, but to professional whale watchers, no two are alike, and that's where things get interesting for marine biologists.

Gillian Deacon
In the waters around Vancouver Island in 1972, an idea was born... an idea that revolutionized the way killer whales, or orcas, are studied around the world. Dr. Michael Bigg noticed that the whales have unique markings, nicks or scars, on their dorsal fins. He began using photographs of fins and saddlepatches, the pigmented area behind the fin, to identify individual whales.

Lance Barrett-Lennard
The technique of photo identification that Mike Bigg began is being used everywhere else now. It's the first tool. It's the basic thing that people start with. It makes it possible to count the number of animals and to track the fates of individuals through time.

Gillian Deacon
Being able to track individual whales made new avenues of study possible for the researchers following in Dr. Bigg's footprints. He died before genetic testing of the whales began, but had believed that DNA studies were the logical next step.

Lance Barrett-Lennard
The first thing we've learned from the DNA evidence is that killer whales live in two different ecotypes, two different groups, one of which specializes in mammals, one of which specializes in fish. What we've learned is that these groups are genetically very distinct from each another. There's no interbreeding that goes on. They overlap in range. They look pretty similar to each other. They do different things, and they haven't inter-mated for... for at least hundreds, and probably thousands, of years.

Gillian Deacon
They may look alike to us, but they're not the same. One group, the fish eating resident whales, is divided into two communities, the northern residents, and the southern residents. The other group, called transients, hunt sea mammals. When the whale communities were studied for contaminants, disturbing findings surfaced.

Dr. Peter S. Ross
We studied three different communities of killer whales in southern British Columbia and we found that the transient killer whales are now the most contaminated marine mammals anywhere in the world, and they essentially exceed the level of PCB contamination of the endangered St. Lawrence belugas by a factor of five times. The southern residents are two to three times more contaminated than the St. Lawrence belugas.

Gillian Deacon
It's thought that the transient whales, with their diet of marine mammals, are more contaminated than the fish eating residents because they feed on bigger animals that live longer and accumulate more toxins.

Peter Ross
We're still very concerned about the risk that these chemicals might present to the health of these free ranging killer whales. So we are continuing to study... study the issue.

Gillian Deacon
These are, without a doubt, the most studied killer whales in the world today... and probably the most watched too. Even whale watchers can be part of the study process.

Dan Kukat
We're integrally involved with the University of Victoria. We're helping facilitate a study that one of their PhD students right now on marine biology is conducting. He's writing his thesis on human and whale interactions.

Gillian Deacon
There are thousands of times more whale watchers than there are whales to watch. Nonetheless, watchers and scientists alike continue to be captivated by the magnificent killer whales of British Columbia. Michael Bigg would have been pleased to see the interest and diversity of research that's been inspired by his pioneering efforts.

Earth Tones is produced in co-operation with Fisheries and Oceans Canada.