You may recognise the Australian Fur seal from an earlier Creature Feature. These seals can be found in Port Phillip Bay, but you will find them in greater numbers at their breeding colonies.
Victoria has around 13 breeding colonies, but the two largest, Seal Rocks and Lady Julia Percy Island, account for half the pups born each year. At these breeding colonies, males come ashore in October and establish their territory, which they defend until December. When the females arrive, they are ready to give birth with late November being the peak birthing time. The males establish a harem of up to nine females and 6-10 days after they give birth and he will mate with them. The females do not fall pregnant straight away but delay the implantation of the fertilized egg so that the pup will be born in the summer months. The males leave the breeding colony in late December.
The mother spends her time resting, suckling her pup and going to sea to feed. As her pup gets bigger, she can spend longer at sea feeding. The pup will be weaned after around 8 months of age but may remain with the mother until 11 months old. There is high mortality of pups, especially when the mother is at sea feeding.
The breeding colonies of Bass Straight were targeted by fur traders in the 19th century. Their thick fur was sought after in England and China where it was used to make boots and clothing. In one decade, 150,000 seals were killed and after 30 years of sealing they had reduced seals numbers to a point where exporting them was no longer viable. Today seal numbers are estimated at around 120,000 and seals are fully protected in Australian waters.
Australian fur seals can spend up to 7-10 days at sea feeding before returning to land to rest. During their time at sea, the seals may travel long distances to their favourite hunting areas. Seals have been recorded travelling from Seal Rocks to King Island in Bass Straight and ventured as far as the west coast of Tasmania. Rather than return to Victoria to rest, seals will use haul-outs on rocky islands in Bass Straight, which are not breeding colonies, but places to rest before continuing to hunt for food.
Chinaman’s Hat is a haul out in Port Phillip Bay managed by Parks Victoria and home to juveniles, sub-adults and adult Australian Fur Seals. Martin Island off the New South Wales coast is another haul-out site. Watch the seals swim and play with divers in the waters around Martin Island.
If you would like to learn more about seals and the huge diversity of life that be found in our local bays and along our shorelines please contact Education Director Mandy Robertson on education@dolphinresearch.org.au