The humpback whale is one of several baleen whale species found off the coast of Western Australia. They are a moderately large whale species, growing up to 18 metres in length. Humpback whales as the name suggests, have a hump below the dorsal fin, recognisable on individuals surfacing for air. Distinctive markings are often present on the dorsal hump and tail flukes, and these markings along with rounded protuberances on the whale’s head, can be used to identify humpback individuals. In comparison to similar species such as the Southern right whale, the humpback whale has elongated flippers and is generally greyish blue in colour.
Humpbacks are well known for their long migrations which occur annually along the western and eastern coastlines of Australia. Individuals feed in the Southern Ocean during the summer period before travelling north to warmer water during winter, in order to breed and birth calves. The movement of humpback whales along the Western Australian coastline occurs between May-September with the greatest number of individuals observed between June-August. Humpback whales generally migrate within 20 kms of the coastline, with frequent sightings of individuals less than 5kms from shore and in sheltered regions of the coastline such as the Geographe Bay. Humpback whales are often quite active – breaching out of the water or tail slapping at the surface; both behaviours believed to be social actions or to remove parasites including barnacles from their skin.
Occurrence at the Busselton Jetty:
It is not uncommon to see humpback whales from the Busselton Jetty during the migration season between June to September. Individuals can be seen far distances out from the end of the Jetty, however in recent years humpback whales have been observed closer to shore and on two occasions, within 20metres of the underwater observatory.
Image by: Busselton Jetty Inc.