The Action Plan for Australian freshwater fishes
Species recovery outline: Trout Cod, Blue-nose Cod
Scientific name: Maccullochella macquariensis
English names: Trout Cod, Blue-nose Cod
Species taxonomic status: Formally described by Cuvier in Cuvier and Valenciennes, 1829. Only formally distinguished from Murray cod in 1977.
Species survival status:
- Action plan status: Endangered.
- Australian Society for Fish Biology status: Endangered.
- Proposed new IUCN criteria status: Critical (50% probability of extinction in 5 years).
Former distribution: Widespread throughout the upper reaches of the Murray-Darling Drainage Division. Recorded as far downstream as Mannum, South Australia.
Current distribution: Restricted to a few isolated populations in Victoria, New South Wales and the Australian Capital Territory.
- Murray River from Yarrawonga to Barmah (largest natural population).
- Seven Creeks River System (viable translocated population).
- Stocked to the following streams: Koetong Creek, Hughes Creek, Ryans Creek, Buffalo Creek, Coliban River and Broken River. (It is not known if these populations have become self sustaining).
- New South Wales (mostly from stockings):
- Murray River at Yarrawonga.
- Upper Murray River.
- Upper Murrumbidgee River near Cooma.
- Macquarie River near Bathurst.
- Cataract Dam on the Nepean River.
- Talbinga Dam.
- Australian Capital Territory (from stockings):
- Bendora Reservoir.
Habitat: Precise habitat requirements not known. Inhabits fast flowing and still waters. Within streams it is frequently found in fast flowing water over bedrock, boulder and gravel substrates. Smaller fish are found among boulders while larger individuals inhabit deep holes with boulder or snag cover between rapids.
Reasons for decline:
- Effect of recreational angling; set-lining quite important.
- Commercial fishing activities may affect populations in the lower Murray River, although less than recreational fishing.
- Introduced species interactions:
- Possibly from carp (Cyprinus carpio), redfin (Perca fluviatilis) and perhaps goldfish (Carassius auratus).
- Food competition, possibly predation, and other interactions.
- Habitat degradation:
- De-snagging has had a significant effect.
- Dams and weirs prevent dispersal and recolonisation of previous habitats.
- River regulation, with inversion of stream flow patterns and suppression of flooding.
- Loss of native riparian vegetation.
- Possible loss of genetic diversity:
- Diminishing populations.
- Prevention of gene flow because of dams.
- Use of small parent stock size in captive breeding program.
- Release of mass cultured fish in waters that may contain relict populations of genetically distinct groups (possibly Upper Murrumbidgee and Macquarie Rivers).
- Hybridisation/introgression with Murray cod in impoundments.
Conservation reserves on which species occurs:
- Seven Creeks Wildlife Reserve (Vic).
- Buffalo National Park (Vic).
- Kosciusko National Park (NSW).
- Namadgi National Park (ACT).
- Entire length of Murrumbidgee River in the ACT managed as a Nature Reserve
Other public lands on which species occurs:
- State forest, Koetong Creek (Vic).
- Ryans Creek water catchment (Vic).
. Other land on which species occurs: Private land.
Is knowledge about species adequate for objectives and actions to be defined accurately? (If not provide list of additional studies required): No.
Knowledge required on:
- General biology.
- Habitat requirements of various life-history stages.
- Population structure.
- Response to fishing.
- Recruitment process.
- Maintain or expand current distribution and population sizes.
- Reintroduce populations into suitable habitats within the former distribution.
Management actions already initiated:
- New South Wales:
- Review of native fish regulations proposes ban on taking of Trout Cod; closures in Murray River from Yarrawonga to Barooga during September to November, plus existing ban on set lines. Ban on taking of both cod species in the Murray River from Yarrawonga to Barooga still in force.
- Inter-departmental liaison with Water Resources, local government and Murray-Darling Basin Commission (MDBC) to manage habitat better.
- Cooperation and participation in the MDBC's Native Fish Management Plan and in the Trout Cod Restoration Plan based at Snobs Creek and conducted by John Douglas.
- Murrumbidgee River from Tantangara Dam to the storage of Burrinjuck Dam, plus a 40 m riparian corridor has been entered on the Australian Heritage Commission's Register of the National Estate because it is Trout Cod habitat.
- Program of captive breeding and re-establishment of wild populations based at the Inland Fisheries Research Station since 1987. A target total of 20 000 fingerlings are released into relatively protected and good quality wild habitats (mostly rivers, but some impoundments also) throughout the natural range in NSW and ACT.
- Survey of the Murray and Murrumbidgee Rivers for Trout Cod funded by ANPWS Endangered Species Program.
- Listed on Schedule Two of the Flora and Fauna Guarantee Act.
- Action Statement in preparation; includes establishment of new viable populations and restoration of riparian zones in the Seven Creeks catchment.
- A ban on the taking of Trout Cod has been imposed.
- The section of Seven Creeks containing Trout Cod has been closed to fishing. (It has been proposed that this section be extended in a review of fishing regulations.)
- Murray River between Yarrawonga and Cobram (near Barooga) has been closed to fishing for all cod species.
- Captive stocks maintained to supply fingerlings for restocking.
- Australian Capital Territory:
- Listed on Schedule One of the Nature Conservation Act 1980 as a protected fish.
- Listed on Schedule Six of the Nature Conservation Act 1980 as a species with special Protection Status.
Management actions required:
- Declaration of additional conservation reserves: Yes.
- Need to protect the Murray River population.
- Upgrade Seven Creeks Reserve.
- Habitat management: Yes.
- Review flow regimes and temperatures for Murray River population.
- Review of river management practices at all other sites.
- Develop emergency procedures for toxic inputs into existing populations.
- Feral animal control:
- Monitoring of trout and other introduced species present. Make assessment for their control or removal.
- Translocation or re-establishment of populations: No.
- Restocking within existing range appears to be having some success.
- Captive breeding:
- Continue existing programs in New South Wales and Victoria.
- Other: No.
Organisations responsible for conservation of species:
- Victorian Department of Conservation and Natural Resources.
- Department of Agriculture and Fisheries, New South Wales.
- Australian Capital Territory Parks and Conservation Service.
Other organisations or individuals involved:
- John Douglas, Department of Conservation and Natural Resources, Snobs Creek.
- Department of Conservation and Natural Resources, regional staff (Benalla).
- Native Fish Australia.
Can recovery plan be carried out with existing resources?: Yes.
- Providing that funding of projects relating to the conservation of trout cod as part of the Murray-Darling Basin Commission Natural Resources Management Strategy continues. Additional funding requirements may be identified in the Trout Cod Restoration Plan being prepared with ANPWS funding.
- Trout Cod/Murray cod hybrids have been confirmed from Cataract Dam and the Murray River (Yarrawonga) populations.