Our research is providing insight into white shark movement patterns and behaviour, juvenile nursery areas, and adult population estimates for the eastern and southern-western Australasian populations.

Movement of white sharks

White sharks occur in coastal, shelf, and continental slope waters around Australia from the Montebello Islands in north-western Western Australia, south around the coast to central Queensland including Tasmanian waters.

DNA sampling and tagging: researchers search for juvenile white sharks off the coast of Port Stephens, NSW

The sharks' movements indicate a pattern of temporary residency at favoured sites intermixed with periods of long-distance travel that may include common corridors.

They are not permanent residents at any one site.

Areas close to favoured sites and common corridors of travel are likely to experience higher encounter frequencies with white sharks.

There is no scientific evidence showing tagged sharks being involved in human encounters.

Why are white sharks vulnerable?

White sharks are long-lived and slow growing species. Females do not reproduce in Australian waters until approximately five metres in length and about 16 years of age. Males are sexually mature at a smaller size and slightly younger age.

The gestation period for adult females is 18 months and they produce few young, called 'pups' (up to 10 per reproductive event), and do not reproduce each year.

These characteristics mean white shark populations are vulnerable to low levels of exploitation (including incidental bycatch) and are slow to recover once they are depleted.

Two Australian populations

Genetic and tracking evidence reveal there are two white shark populations in Australia, an eastern population (ranging along the east coast from Tasmania to central Queensland) and a southern-western population ranging from western Victoria to northwest Western Australia.

This population structuring east and west of Bass Strait is consistent with a number of other species of sharks, finfish and invertebrate species in Australian waters.

Short-term local increases and decreases in sightings frequency, encounters and shark attacks are, by themselves, poor predictors of shark population status.

White shark video 200831 

[Music plays and the CSIRO and Marine Biodiversity Hub logos appears and an image appears of a white shark swimming and small fish appear swimming around the shark and text appears: White sharks are vital to marine ecosystems]

[Image changes to show a white shark swimming and a school of fish swimming beneath it and text appears: They are vulnerable to threats and protected internationally]

[Image changes to show a close view of three crew members on a boat hauling on a rope and text appears: In a landmark study, we used a cutting-edge genetics tool…]

[Image changes to show a white shark swimming through a school of fish and text appears: … to estimate how many white sharks there are]

[Image changes to show a simulation of a white shark swimming along the ocean bed and text appears: In Australian waters there are two populations – eastern and southern-western]

[Image changes to show a close view of a rope in the water and text appears: We estimate there are 5,500 white sharks living off Australia’s east coast]

[Image changes to show a grey nurse shark swimming in the ocean and text appears: This science is being used for other species too, such as grey nurse sharks and tuna]

[Image changes to show a simulation of an aerial view of a circle around a white shark swimming between Receiver points A, B, and C and text appears: Together with the NSW Department of Primary Industries, we’re also tracking white shark movements and behaviour…]

[Image changes to show a close view of a hands holding a shark by the fin in the water and checking the satellite tag on the fin and text appears: … using satellite and acoustic tags]

[Image changes to show a map of a shark’s journey up and down the coast of Victoria and New South Wales and text appears: White sharks can travel thousands of kilometres, even to New Zealand but they rarely cross the Bass Strait]

[Image changes to show an animation of a white shark swimming past a receiver towards the camera along the ocean floor and text appears: Our breakthrough research is providing new and innovative insights…]

[Image changes to show a white shark swimming with a school of tuna and text appears: … to understand the lives of white sharks, and help with ongoing management]

[Image changes to show a black screen and text appears: csiro.au/sharks]

[Image changes to show the CSIRO logo and text appears: CSIRO, Australia’s National Science Agency]

Breakthrough science to understand the lives and movements of white sharks

Nursery areas

White sharks can have highly localised and geographically discrete inshore nursery areas which include surf zone habitats. Sharks in these nursery areas are typically 1.7–3 metres in length.

At nursery areas close to human population centres, the frequency of encounters between people and sharks can be high, although the frequency of attacks in such areas is very low.

International travels

White sharks move between eastern Australia and south Pacific waters (including New Zealand) and between South Africa and Western Australia.

The population implications of these movements are unknown.

White sharks in Western Australia are part of a combined South Australia/Western Australia population and travel between western Victorian and northwestern Australian waters with possible links to South Africa.

Shifts in abundance

The local abundance of white sharks in shelf and coastal waters varies seasonally and between years as a result of variations in their distribution and movement patterns.

The drivers for these variations are poorly understood but are likely to include factors influencing prey distribution and variations in the physical ocean environment. We are working with the NSW Department of Primary Industries to carry out further data analysis to determine other potential contributing factors.

Short-term (seasonal/annual) local increases and decreases in sightings frequency, encounters and shark attacks are thus, by themselves, poor predictors of shark population status.

Electronic tagging studies have located two nursery areas for juvenile white sharks in eastern Australia: the Port Stephens region of New South Wales and 90 Mile Beach-Corner Inlet region of eastern Victoria.

The more accessible of these regions is a 50–60 kilometre stretch of coastline centred on the Port Stephens area where sharks occupy habitat from the shore to approximately 120 metres depth.

They also spend a significant amount of time in the surf zone in water depths of one to five metres where they are more frequently seen by the public.

Juvenile white sharks aggregate in the Port Stephens region from early spring to mid-summer. The sharks are usually 1.8 to 2.6 metres in length and approximately one to five years old.

They stay for weeks or months in local areas of the coast, specifically along northern Stockton Beach, Bennett's Beach and Mungo Brush.

Contributing to population estimates

The tagging program aims to establish the patterns of residency and habitat use by juvenile white sharks and to contribute information on the overall movement and population dynamics of juvenile white sharks on the east coast of Australia. By using DNA sampling from juvenile sharks, we can also estimate adult white shark numbers.

This information, combined with estimates of adult numbers from the genetic data, have contributed to Australia's first white shark population estimates and models that use measured data to asses population status, rather than information that is assumed or best-guessed.

Our research provides key information on populations of adult eastern and southern-western white sharks, as well as helping to determine the survival rate of adults and juveniles.

As more juveniles are sampled over time, the parental marks we detect can reveal patterns of adult survival, which we determined to be greater than 90 per cent.

Estimating the trend in total population size for both populations requires sampling and analyses, developing methods and continued collaboration with our partners. This will help to inform policy and conservation efforts for white sharks in Australia.

In the 2012-2013 season, about 250 juvenile white sharks may have been present in the nursery area on survey days with peak abundance in October-November, as previously observed for the region.

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