Abyss Scuba Diving

What Is Sydney's Most Common Shark?


What is Sydney's Most Common Shark?

The Port Jackson Shark is the common shark seen by divers in the waters around Sydney. Port Jackson Sharks are considered non-threatening to humans. Their teeth are not sharp, yet they can give a painful bruising bite. If provoked, they have also been known to bite and expend considerable energy attaching themselves to the diver, leaving a visible hickey-like bruise.

This medium-sized Australian shark has a blunt head with a small mouth and prominent crests above its eyes. It is usually a light grey brown with black bands across its eyes and keels across its back that run diagonally. It is lovingly known as a PJ to Sydney divers.

The breeding season for the Port Jackson shark typically takes place during late winter and early spring. During this time, they are most prevalent around Sydney and divers often observe the sharks gathering in caves, under ledges, and in gutters, particularly during the winter months.

Female Port Jackson sharks lay eggs. The egg case is a tough, chestnut brown spiral about 7 cm to 8 cm wide and 15 cm long. It is common for them to be found washed up on beaches. Females can lay up to sixteen eggs during each breeding season. An embryo develops for 10-11 months before hatching from its egg capsule completely.

According to a tagging study that Abyss was involved with in 2000, Sydney sharks migrate vast distances each year (600-800 kilometres) between their feeding grounds in Bass Strait and reproductive aggregations along the New South Wales coast.

PJ’s sharks can grow up to 1.65 meters and can live for 30 years. Female Port Jackson sharks mature at 11 to 14 years of age, with males maturing at 8 to 10 years.

PJ’S forage for food at night when their prey is most active. They eat molluscs, crustaceans, sea urchins, and small fish. They often use caves and rocky outcrops as protection during the day, although if you examine the sand to the east of Bare Island during September to October, you will discover them laying there by the hundreds.

Where Can You Dive with Port Jackson Sharks in Sydney?

Port Jacksons can be found at various dive sites around Sydney from July to September. However, if you are interested in seeing large groups of these sharks, I would suggest going to Cape Solander, the western side of Bare Island, and Fish Soup at Oak Park.

If you are interested in observing a baby Port Jackson shark, they are often located at Bass & Flinders and Oak Park during January and February. During those months, we do organize special dives to observe the Port Jackson sharks.