Whales

The white and grey  fluke of a humpback whale above the surface of the water
Humpback whale (Photo: Nick Gales)
A minke whale surfaces off the Antarctic coastBlack and white back of the killer whale spouting water

Whales belong to a wonderfully diverse group of the most aquatically specialised of the world's mammals called Cetaceans. Should a similar law to that protecting seals protect whales? Why is there no such law?

See the Antarctic wildlife size comparison page for a list of the approximate sizes and weights of whales found in the southern hemisphere, and the best estimates of their original and present abundance. (Source: International Whaling Commission whale population estimates)

  • As with the seal activities (and preferably combined with them), have students weigh themselves and work out how many individuals are needed to equal the weight of each whale. The students could also measure their height and compare the length of children to each type of whale. (Blue whales may be the largest animals that ever lived, although it's now thought that some sauropods (herbivorous dinosaurs) may have been larger. The biggest blue whale ever weighed was nearly 200 tonnes and over 30 m in length!)
  • Students can create life-size scale drawings of whales, either with chalk on the playground, or in the school hall or hallways (if you can get butcher’s paper large enough).
  • Ask students to use the whale table to draw a graph that shows both the original estimated numbers, and current estimated numbers, of different whale species.
  • What has been the decline in each species - in numbers, and in biomass? The massive reduction in the stock of whales as a result of commercial whaling activities is the single largest human impact to the Southern Ocean ecosystem. Ask the students to suggest reasons why the population of minke whales has increased. (Minke whales have only been commercially hunted since the 1970s, after the stocks of blue and fin whales were exhausted.)
  • Japan kills about 300 to 600 minke whales a year in the Southern Ocean for scientific research. As the minke whale populations is so large, should sustainable whaling in Antarctica be allowed? If not, why not? Are whales a special species that need to be specially protected? Is it more profitable to take tourists to watch whales, or to hunt them and sell their meat?
  • Ask students to research the history of whalers and whaling. If whalers operated out of your local port in the 19th century, ask students to research the local history of whaling.

It is very difficult to accurately determine the number of whales of different species. The size of most whales populations is only known to an accuracy of plus or minus 50%. All population estimates are based on a count of the whales sighted on each side of a survey vessel as it zigzags its way through a designated stretch of water.

  • Ask students to discuss why it is difficult to make accurate counts of whales numbers. (Only a small percentage of whales will be visible on the surface as the vessel passes. Seeing whales is very dependent on sea and light conditions. As whales are now so rare and widely dispersed, extrapolations must be made from the sightings of only a tiny fraction of the populations.)

Further information

Information on blue, humpback, minke, sei and southern right whales and orcas is available on the Australian Antarctic Division's whale pages.

See the whale section of the Department of Sustainability, Environment, Water, Population and Communities website.

Don't miss the ABC's whale dreams.

The American Cetacean Society's website features a teachers' guide to introducing and using whales, dolphins, & porpoises in the classroom and ACS cetacean fact packs.

This page was last modified on January 23, 2014.