The Action Plan for Australian freshwater fishes
Species recovery outline: Mary River Cod
Scientific name: Maccullochella sp.B
English Names: Mary River Cod, Eastern Cod, Eastern Freshwater Cod
Species taxonomic status: Formally described by Rowland (in press). Only recently recognised as distinct from Murray cod (Maccullochella peelii) and Clarence River Cod (Maccullochella sp.A).
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, total population possibly less than 250, population fragmented, observed habitat alteration, inferred interaction with translocated species).
Former distribution: Mary River Cod occurred throughout the Mary River Drainage Basin. This species is possibly identical to the species that occurred in the Brisbane River Drainage, Logan Albert Drainage and Coomera Drainage.
Current distribution: Mary River Cod are currently restricted to a few larger tributaries of the Mary River: Obi Obi Creek, Six Mile Creek, Tinana Creek and Coondoo Creeks. Individual specimens are occasionally captured in other tributaries and the Mary River proper.
Habitat: Mary River Cod are found in deeper pools of relatively undisturbed tributaries where fallen timber, branches and boulders provide cover.
Reasons for decline:
- Dams and weirs destroy physical habitat and alter water quality. Also prevent dispersal and recolonisation of previous habitat.
- River regulation with loss of dry weather stream flow and suppression of minor flooding.
- Loss of native riparian vegetation.
- Extensive stream siltation from accelerated catchment erosion due to agriculture and forestry.
- Stream channel damage from sand and gravel extraction.
- Alteration, particularly through siltation, of stream macroinvertebrate communities that provide food.
- Possible competition with translocated species: golden perch (Macquaria ambigua) and silver perch (Bidyanus bidyanus).
- Overfishing by recreational anglers.
Conservation reserves on which species occurs: A number of conservation reserves (including Kondalilla National Park) adjoin streams that support populations of Mary River Cod. However these do not protect the habitat of Mary River Cod or the fish itself.
Other public lands on which species occurs: A large number of forestry areas exist in the Mary River catchment and several include streams containing cod.
Other land on which species occurs: Large areas of private land.
Is knowledge about species adequate for objectives and actions to be defined accurately? (If not provide list of additional studies required): No.
Baseline data to allow ongoing monitoring of populations must be collected:
- Need to determine the distribution and relative abundance throughout the Mary River Drainage.
- Need to determine the age structure and level of recruitment in remaining populations.
- Need to obtain information on specific habitat requirements and potential threats to their habitats.
- Further develop hatchery techniques to ensure adequate fingerling supplies.
- Initiate Government controlled breeding program.
- Assess viability of populations in artificial impoundments.
- Maintain current distribution and abundance.
- Expand present distribution within the former range of the species, by renovating habitat and restocking.
15. Management actions already initiated:
- Surveys of rivers within the former distribution have been completed. No other populations were found.
- General knowledge of the broad distribution within the Mary River Catchment is available.
- General assessment of the condition of streams within the basin is in progress.
- Development of spawning techniques investigated by local government hatchery. Success to date limited (in comparison to other Maccullochella species).
- Investigation of the distribution and abundance throughout the Mary River drainage commenced in August 1993 with ANPWS funding.
- Fingerlings stocked into impoundments in Mary River, Brisbane River, Logan River and Nerang River Drainages. Fish from impoundments have high growth rates and appear to be maturing, however no breeding has been reported.
- Proposal for a bag limit of one presently being considered by Government.
Management actions required:
- Declaration of additional conservation reserves: Yes.
- Must be able to protect instream habitat. This implies the protection of stream catchments.
- Habitat management: Yes.
- Engineering projects to renovate streams (reduce bank erosion, re-establish stream morphology, replant banks).
- Maintenance of instream flows.
- Feral animal control: Yes.
- Determine impact of introduced native species and stop introductions if necessary.
- Ban the introduction of Murray cod into the Mary River drainage, including private farm dams.
- Translocation or re-establishment of populations: Yes.
- Continue re-stocking into drainages within the original range and monitor success.
- Captive breeding: Yes.
- Continue development of hatchery techniques.
- Other: Yes.
- Control recreational fishing.
- List under Nature Conservation Act 1992.
Organisations responsible for conservation of species:
- Queensland Department of Primary Industries.
Other organisations or individuals involved:
- Noosa Shire Council, Gerald Cook Hatchery, Lake MacDonald.
Can recovery plan be carried out with existing resources?: No.
- ANPWS funding is available for a study on the distribution and abundance of Mary River Cod. Queensland Department of Primary Industries is funding the development of hatchery technology to improve the success of captive breeding. Additionally the Mary River catchment has become a pilot catchment for the Queensland Department of Primary Industries' Integrated Catchment Management program. The thrust of the Species Recovery Outline is to obtain the required information on the habitat and fish distribution in the Mary River and to integrate this information into a catchment management plan. Additional funding will be required to implement aspects of Catchment Management Plan relevant to Mary River Cod.
- General monitoring of survival and growth of this species in impoundments can be achieved through the Queensland Department of Primary Industries catch record cards and creel surveys. Specific monitoring to determine spawning success in impoundments and survival within the natural habitat may require additional funds. Volunteers from angling groups are available to assist in field work. One biologist would be required for four weeks to coordinate monitoring and document results – $3 480, plus car hire and camping allowance – $2 400.
Annual monitoring: $5 880
- The Queensland Department of Primary Industries will investigate the value of having this species listed under the Nature Conservation Act 1992.