Freshwater Turtles

Risk Assessment: None completed for Tasmania

Tasmania has no native freshwater turtles and any freshwater turtle spotted in Tasmania is an invasive species.

History

Prior to regulations in 1974 restricting the removal of reptiles from the wild throughout mainland Australia, large numbers of freshwater turtles were harvested from the wild and sold to pet shops throughout southern Australia including Tasmania. Turtles of several species were openly sold as novelty pets throughout Tasmania. Some of these animals escaped or were released into the wild and large, adult individuals from this era are still discovered in the wild (in Tasmania) from time to time.

Captive bred turtles are still sold legally as pets on mainland Australia. Due to their small size, hatchlings are relatively easy to transport and there have been a number of recent incidents where people have been caught smuggling them into Tasmania.

Recent evidence indicates that the long-necked turtle (Chelodina longicollis) may be breeding in Tasmanian waterways but little is known about the size of the population or extent of their distribution. As such, it is vital that all turtle sightings are reported so that appropriate management action can be taken.

Distribution

There are more than 20 species of freshwater turtle native to mainland Australia and they are found in most of freshwater lakes and rivers. Tasmania has no native freshwater turtles and any freshwater turtle spotted in Tasmania is an invasive species.

The following distribution information is provided for the long-necked turtle, which may be found as an invasive species in Tasmania.

Case study: Long-necked turtle (Chelodina longicollis)

Long-necked turtles are native to mainland Australia and common from eastern Queensland to south eastern South Australia. They generally prefer slow-moving waterways, lakes and swamps.

This species is highly mobile and can travel up to 2 km overland, particularly after rain, in search of new feeding or nesting sites. Once in waterways they can spread quickly and are difficult to eradicate. A warming climate may aid turtle establishment in new areas outside their existing range.

In Tasmania, records and reports have been received for long-necked turtles in Low Head, Fern Glade near Burnie, Brighton, Sorell, Launceston, Longford and Lorinna. Turtles have generally been identified around farm dams. Long-necked turtles have also been collected from both King and Flinders Islands.

Most recently, an adult long-necked turtle and turtle nest (with eggs and hatchlings) was identified at a property in Spreyton in 2013.


Adult long-necked turtle, hatchlings and turtle eggs found at Spreyton in 2013, © ISB, DPIPWE

Environmental Impacts

Turtles have a diet that commonly includes molluscs, crustaceans, tadpoles and small fish. They may pose a threat to some Tasmanian species, such as native galaxiids and the vulnerable green and gold frog. Turtles may also compete with other local species for food sources.

Turtles can cause environmental damage through digging of nests and burrows in sand or soft sediments. This may affect water quality and stability of stream banks and dam walls. They may also transmit disease to local reptiles and amphibians.

Reproduction

On mainland Australia, turtle mating typically occurs during spring. Turtles will dig a shallow burrow in soil or sand to lay their eggs. Turtle eggs are small and white, and up to 20 eggs may be found in a nest.

Nests are commonly located in an exposed site with good sun near a water body, such as in a dam wall or stream bank, but may also be found some distance away from water in a field or paddock.

Young turtles are called hatchlings and may be about the size of a 20 cent piece. Colour may vary between species but they are predominantly black. Hatchlings look like miniature versions of adult turtles.

To report turtle sightings in Tasmania, or for further information about turtles, please contact the Invasive Species Branch on 03 6165 3777, or by email to: invasivespecies@dpipwe.tas.gov.au

The Tasmanian public, particularly farmers, anglers and aquarists, should be on high alert for this species and report all sightings, including the dumping of unwanted turtles. Early detection and rapid response to incursions is vital.

Did you know?

The long-necked turtle may eject a foul-smelling secretion when disturbed leading to the common name for this species, 'Stinker'.

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See other invasive species profiles:

Mammals | Birds | Other species

 

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