Blue Whales are endangered and are a protected species under Australian and international law. A sanctuary extending 370 kilometres from shore and continuing around the entire coastline has been declared. Until the beginning of the 20th century, Blue Whales were in abundance, but for 40 years they were hunted almost into extinction. The international community stepped in to stem the slaughter in 1966.
A 2002 report estimated there were between just 5000 and 12,000 Blue Whales worldwide located across five groups.
Believed to be the largest animal to have ever lived, the long and slender Blue Whale grows up to 33 metres long and weighs 181 tonnes or more. They can be various shades of bluish-grey dorsally and lighter underneath. Their 180-decibel whale song is much louder than a jet engine.
When surfacing to breathe, the Blue Whale raises its shoulder and blowhole out of the water to a greater extent than other large whales. This trait may be used by observers to differentiate between species at sea.
When breathing, the whale emits a spectacular vertical single column blow up to 12 metres. On a calm day it can be seen from a great distance. The whales have twin blowholes, shielded by a large splashguard.
They can reach speeds of 50km/h over short bursts when interacting with other whales, but normally creep along at 20km/h. When feeding they slow down to five km/h.
Blue Whales most commonly live alone or with one other. It is not known if they stay as couples over long periods or form other relationships. They do not form large close-know groups as seen in other whale species.
Unlike Humpback and Southern Right whales, Blue Whales are rarely close enough to the shore to be seen and the very best way to admire these magnificent creatures is from on high. Heli-Explore, based in Portland, Victoria, is Australia's only helicopter operator offering blue whale watching flights.
Portland, on the far western side of Victoria along the Great Ocean Road, is at the start of Bass Strait. It is used by many species of whales on their migratory paths both east and west. They arrive every year from as early as November and stay until as late as May. Researchers know very little about where they go.
They arrive for the krill-rich waters of the Bonney Upwelling, a southern ocean upwelling of cold Antarctic waters. Every year, in varying strengths and frequency, the waters are drawn beneath the Southern Ocean to upwell along the western Victorian and South Australian coastline.
Blue Whales require around five tonnes of food a day, so the krill provided by the Bonney Upwelling is critical for their survival.