Trout Cod (Blue-nose or Rock Cod) (Maccullochella macquariensis)
Threatened Species Day Fact Sheet
The Trout Cod is similar to the well-known Murray Cod, except it has a straighter head, longer snout and an overhanging top jaw. They typically grow to about 50 centimetres and eat shrimp, smaller fish, crayfish, aquatic insects, and frogs.
The Trout Cod is listed as endangered under the Environment Protection and Biodiversity Conservation Act 1999. This Act is the main Commonwealth legislation for protecting the environment and conserving biodiversity.
The species was once widespread throughout the southern Murray-Darling Basin, but it has undergone a drastic reduction in range and abundance in the last century. Currently only two breeding populations of Trout Cod are known, one in New South Wales and another in Victoria.
Trout Cod habitat is not well understood, but they appear to favour deep, fast flowing waters. Cover is vital, and they are often found sheltering under snags (woody debris).
Habitat degradation through removal of woody debris, siltation and reductions in water quality as well as modification of waterways threaten this species. Introduced pests such as Carp and European Trout compete with and prey upon the Trout Cod and they are also over-fished in some areas.
Fishing for Trout Cod is banned in New South Wales, Victoria and the Australian Capital Territory. Environmental water flows are being returned in some catchments and projects are being undertaken to 're-snag' waterways and revegetate streamside areas.
The Australian Government's Natural Heritage Trust, in partnership with the State Governments, is funding the revision of the national recovery plan for this species. Work is underway to develop freshwater conservation areas and restocking programs are occurring. Control of invasive species such as European Trout is also taking place in some areas.
Here is how you can help the Trout Cod and other threatened fish species:
- avoid fishing in areas where Trout Cod are found;
- assist local groups in your area to repair freshwater habitat;
- report sightings of the Trout Cod — contact your local coordinator at the details given on this fact sheet;
- do not release introduced fish into our waterways.
A snag is a fallen tree or branch that is lying in water. Snags provide fish with protected breeding sites as well as shelter from predators, strong currents and direct sunlight. They also provide a habitat for many aquatic plant species.
Snags play an important role in keeping our watery worlds clean. They stabilise banks and river beds and help to mix up and oxygenate the water. By trapping debris as it comes down the river, snags create food sources for algae and other micro-organisms. This, in turn, provides a food source for a wide variety of fish and other aquatic species.
Snags also provide habitat for non-aquatic species. They can be used as a sunny resting spot by lizards, turtles and frogs as well as providing roosting sites for many bird species.
Historically, snags have been removed from waterways for a number of reasons. They were believed to increase the severity of flooding, were unsightly, and unsafe for swimming and watercraft. Snag removal programs were introduced across Australia. In addition, removal and dieback of streamside vegetation has led to less natural snag creation.
Many river restoration programs are underway throughout the country, reintroducing snags to our waterways. In cooperation with revegetation schemes, this can go a long way to recreating habitat diversity and reversing the decline in our native fish populations.
Telephone: 02 8202 1222
You can also find out more information about Australia's threatened species by calling the Department of the Environment and Heritage Community Information Unit on free call 1800 803 772 or by visiting www.deh.gov.au/biodiversity/threatened