The Mary River Cod Research and Recovery Plan

Robert Simpson and Peter Jackson
Queensland Department of Primary Industries, Fisheries Group

References

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  • Barlow, C. G. (1991). Fish for stocking farm dams with a note on predation by cormorants. In G. McCormack and P. Jackson (eds.) The Farm Fish Book. Queensland Department of Primary Industries, and Queensland Country Life Newspaper Pty. Ltd.
  • Berra, T. M. and A. H. Weatherley. (1972). A systematic study of the Australian freshwater serranid fish genus Maccullochella. Copeia 1972(1) : 53-64.
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  • Johnson, I.C. (1985). Fishladder Function and Design for Queensland Streams. Ph.D. Thesis, Zoology Dept., University of Queensland.
  • Johnson, W. C. (1992). Dams and riparian forests: case study from the upper Missouri River. Rivers 3 : 229-242.
  • Lake, J.S. (1971). Freshwater Fishes and Rivers of Australia. Nelson, Melbourne.
  • Llewellyn, L. C., and M. C. McDonald (1980). Family Percichthyidae. Australian freshwater bass and cods. In R. M. McDowall (ed.) Freshwater Fishes of South-eastern Australia. pp.142-149. (Reed: Sydney).
  • Lloyd, L. N. (1990). Ecological interactions of Gambusia holbrooki with Australian native fishes, p. 94-97. In D. A. Pollard (editor) Proceedings of the Australian Society for Fish Biology's Workshop on Introduced and Translocated Fishes and their Ecological Effects. Magnetic Island, Townsville, August 1989. Bureau of Rural Resources Proceedings No. 8. Australian Government Publishing Service, Canberra.
  • MacDonald, C.M. (1978). Morphological and biochemical systematics of Australian percichthyid fishes. Aust. J. Mar. Freshwat. Res. 29 : 667-698.
  • Macleay, W. (1883). Notes on a collection of fishes from the Burdekin and Mary Rivers, Queensland. Proc. Linn. Soc. NSW. 8 : p.200.
  • McCulloch, A. R. and G. Whitley. (1925). A list of the fishes recorded from Queensland waters. Mem. Qld. Museum 8(2) : 125-182.
  • McKay, R. and J. Johnson. (1990). The freshwater and estuarine fishes. In P. Davie, E. Stock and D. Low Choy (eds) The Brisbane River. The Australian Littoral Society Inc.
  • Merrick, J.R. and G.E. Schmida (1984). Australian Freshwater Fishes : Biology and Management. Griffin Press Limited, S.Aust.
  • Murphy, M.L., C.P. Hawkins and N.H. Anderson (1981). Effects of canopy modification and accumulated sediment on stream communities. Trans. Am. Fish. Soc. 110 : 469-478.
  • Ogilby, J. D. (1893). Edible Fishes and Crustaceans of New South Wales. Government Printer, Sydney.
  • Ogilby, J. D. (1916). The Commercial Fishes and Fisheries of Queensland. Government Printer, Brisbane.
  • Palmer, P. J., J. B. Burke, D. J. Willett, and R. R. Simpson. (1992). Development of a low-maintenance technique for rearing barramundi (Bloch) larvae. Queensland Department of Primary Industries Information Series QI92036, Brisbane.
  • Pellett, T. D., G. J. Van Dyck and J. V. Adams. (1998) Seasonal Migration and Homing of Channel Catfish in the Lower Wisconson River, Wisconson. North American Journal of Fisheries Management 18: 85-95.
  • Prokop, F. (1991). The story of our eastern freshwater cod. Freshwater Fishing Australia. 14 (Autumn 1991) : 62-68.
  • Pusey, B. J., A. H. Arthington, and M. G. Read (1993). Spatial and temporal variation in fish assemblage structure in the Mary River, south-eastern Queensland: the influence of habitat structure. Env. Biol. Fish. 37(4) : 355-381.
  • Queensland Water Resources. (1990). Mary Region Overview. Unpublished internal planning report, Queensland Department of Primary Industries Water Resources.
  • Queensland Water Resources. (1993). Water Supply Sources for the Sunshine Coast and the Mary River Valley. Information paper, Queensland Department of Primary Industries Water Resources.
  • Roughley, T. C. (1951). Fish and Fisheries of Australia. Angus and Robertson Pty Ltd, Sydney.
  • Rowland, S. J. (1985). Aspects of the Biology and Artificial Breeding of the Murray Cod Maccullochella peelii, and the Eastern Freshwater Cod M. Ikei sp. nov. (Pisces: Percichthyidae). Ph.D. Thesis, Macquarie University.
  • Rowland, S. J. (1989). Aspects of the history and fishery of the Murray cod, Maccullochella peelii (Mitchell) (Percichthyidae). Proc. Linn. Soc. N.S.W. 111(3) : 201-213.
  • Rowland, S. J. (1993). Maccullochella ikei, an endangered species of freshwater cod (Pisces: Percichthyidae) from the Clarence River system, NSW and M. peelii mariensis, a new subspecies from the Mary River, Qld. Records of the Australian Museum. 45 : 121-145.
  • Sanger, A. C. (1993). The Swan Galaxias Recovery Plan: Management Phase. Inland Fisheries Commission, Tasmania.
  • Saville-Kent, W. (1890). Fisheries, Wide Bay District. (Report presented to both houses of parliament). Government Printer, Brisbane.
  • Simpson, R. R. (1994). An investigation into the habitat preferences and population status of the endangered Mary River cod (Maccullochella peelii mariensis) in the Mary River system, south-eastern Queensland. Queensland Department of Primary Industries Information Series QI94011, Brisbane.
  • Theurer, F.D., I. Lines and T. Nelson (1985). Interaction between riparian vegetation, water temperature, and Salmonid habitat in the Tucannon River. Water Res. Bull. 21 : 53-64.
  • Wager, R. and P.D. Jackson. (1993). The Action Plan for Australian Freshwater Fishes. Australian Nature Conservation Agency, Canberra.
  • Whitley, G. P. (1937). Further ichthyological miscellanea. Mem. Qld. Museum. 11(2) : 113-148.
  • Wyville Thomson, C. (1880). Report on the Scientific Results of the Voyage of H.M.S. Challenger During the Years 1873-1876. Her Majesty's Stationery Office, London.

Bibliography of publications containing information on Mary River Cod

  • Barlow, C. G. (1991). Fish for stocking farm dams with a note on predation by cormorants. in The Farm Fish Book. (ed. by G. McCormack and P. Jackson) Queensland Department of Primary Industries, and Queensland Country Life Newspaper Pty. Ltd.
  • Berra, T. M. and A. H. Weatherley. (1972). A systematic study of the Australian freshwater serranid fish genus Maccullochella. Copeia 1972(1): 53-64.
  • De Vis, C. W. (1901). Natural history. Queensland Official Year Book, 1901. p. 111.
  • Hajkowicz, A. and B. Kerby. (1992). Fishways in Queensland: Supporting Technical Information. Queensland Dept. Primary Industries, Brisbane.
  • MacDonald, C.M. (1978). Morphological and biochemical systematics of Australian percichthyid fishes. Aust. J. Mar. Freshwat. Res. 29 : 667-698.
  • Macleay, W. (1883). Notes on a collection of fishes from the Burdekin and Mary Rivers, Queensland. Proc. Linn. Soc. NSW. VIII: 200.
  • McCulloch, A. R. and G. P. Whitley. (1925). A list of the fishes recorded from Queensland waters. Mem. Qld. Museum VIII(II): 125-182.
  • McKay, R. and J. Johnson. (1990). The freshwater and estuarine fishes. in The Brisbane River. (edited by P. Davie, E. Stock and D. Low Choy). The Australian Littoral Society Inc.
  • Merrick, J.R. and G.E. Schmida (1984). Australian Freshwater Fishes : Biology and Management. Griffin Press Limited, S.Aust.
  • O'Connor, D. (1897). Fish acclimatisation in Queensland. Proc. Royal Soc. Qld. 12: 108-110.
  • Ogilby, J. D. (1893). Edible Fishes and Crustaceans of New South Wales. Government Printer, Sydney.
  • Ogilby, J. D. (1916). The Commercial Fishes and Fisheries of Queensland. Government printer, Brisbane.
  • Prokop, F. (1991) The story of our eastern freshwater cod. Freshwater Fishing Australia (Autumn 1991).
  • Queensland Water Resources. (1990). Mary Region Overview. Unpublished internal planning report, Queensland Department of Primary Industries Water Resources.
  • Queensland Water Resources. (1993). Water Supply Sources for the Sunshine Coast and the Mary River Valley. Information paper, Queensland Department of Primary Industries Water Resources.
  • Rowland, S. J. (1985). Aspects of the biology and artificial breeding of the Murray cod Maccullochella peelii, and the eastern freshwater cod M. Ikei sp. nov. (Pisces: Percichthyidae). Ph.D. Thesis, Macquarie University.
  • Rowland, S. J. (1988). Eastern freshwater cod (Maccullochella ikei): identification, status, conservation and potential threats. In S.J. Rowland and R. Barlow (eds.) Proceedings of a Fish Genetics Workshop. N.S.W. Agriculture and Fisheries.
  • Rowland, S. J. (1989). Aspects of the history and fishery of the Murray cod Maccullochella peelii (Mitchell) (Percichthyidae). Proc. Linn. Soc. NSW. 111.
  • Rowland, S.J. (1993). Maccullochella ikei, an endangered species of freshwater cod (Pisces: Percichthyidae) from the Clarence River system, NSW and M. peelii mariensis, a new subspecies from the Mary River, Qld. Records of the Australian Museum. 45:121-145.
  • Saville-Kent, W. (1890). Fisheries, Wide Bay District. (Report presented to both houses of parliament, Queensland). Government Printer, Brisbane.
  • Simpson, R. R. (1994a). An investigation into the habitat preferences and population status of the endangered Mary River cod (Maccullochella peelii mariensis) in the Mary River system, south-eastern Queensland. Queensland Department of Primary Industries Information Series QI94011, Brisbane.
  • Simpson, R. R. (1994b). The story of Mary River cod. Freshwater Fishing Australia. 27: 104-108.
  • Steptoe, W. (1986). The last bastion. Modern Fishing (Australia). March.
  • Wager, R. (1993). The distribution and conservation status of Queensland freshwater fishes. Queensland Dept. Primary Industries Information Series.QI93001, Brisbane.
  • Wager, R. and P.D. Jackson. (1993). The Action Plan for Australian Freshwater Fishes. Australian Nature Conservation Agency, Canberra.
  • Walker, T. (1994). Enthusiast hooks into Mary River cod. Austasia Aquaculture. 8(3): 20-22.
  • Whitley, G. P. (1937). Further ichthyological miscellanea. Mem. Qld. Museum XI(II): 113-148.
  • Wyville Thomson, C. (1880). Report on the Scientific Results of the Voyage of H.M.S. Challenger - Zoology - Volume I. Her Majesty's Stationery Office, London.

Appendix 1. Costing of budgets

It is anticipated that many of the on-ground actions will be undertaken with assistance from volunteer labour. The time donated by volunteers has not been identified in the budgets.

1. Salaries

The costing of salary components of the Recovery Actions is based on the Queensland Public Service (Remuneration) Interim Award as from 1.5.96. Calculations are based on the following rates of pay:

  • Technical Officer (Level 2) $27 772 - $32 925 per annum
  • Technical Officer (Level 3) $34 905 - $37 741 ' '
  • Biologist (Level 2) $29 489 - $37 741 ' '
  • Biologist (Level 3) $39 651 - $43 295 ' '
  • Biologist (Level 4) $46 097 - $49 858 ' '

On-costs (eg. leave loading, superannuation, administration costs) are calculated at 22% of the salary.

2. Operating

  1. Field Expenses
    The current Queensland Public Service Award (1996) provides the following allowances for officers undertaking field operations:
    • Meals $42 per day
    • Incidental expenses $10 per day
    • Hotel/Motel accommodation $55 per night
    • Camping accommodation remuneration of campsite fees
  2. Vehicle Expenses
    Vehicle hire expenses are included in costings for all actions requiring field work or travel for other purposes. These are based on current (February 1996) lease rates from QFLEET as outlined below. The prices given relate to the 12 month lease rate, and include 40 000 km per vehicle.
    • Toyota Hilux 4WD Deisel Utility Dual-cab $439/month
    • GMH Commodore sedan $220/month

3. Purchase of Materials and Equipment

The purchase of materials or equipment required to carry out any action (eg. stationery, radio-telemetry equipment) will be undertaken according to the guidelines set out in the QDPI Corporate Standard AS.12.002. 'Procurement Procedures'.

Appendix 2. The Mary River Cod Breeding and Restocking Program

Techniques for the captive-breeding of Mary River cod have been developed over the past sixteen years, largely through the efforts of Mr Gerry Cook at the Lake Macdonald Hatchery at Cooroy. Since 1996, daily operations at the hatchery have been managed by the Noosa District Community Hatchery Association (NDCHA), of which Mr Cook is a founding member. The NDCHA provides quarterly reports to a steering committee comprising representatives from Noosa Shire Council (who own the hatchery), Queensland Department of Primary Industries and the Mary River Cod Community Network. A Five Year Strategic Plan developed by the steering committee provides a framework for hatchery operations. The primary objective of the Lake Macdonald Hatchery is the production of Mary River cod fingerlings for a restocking program.

Funding to operate the Lake Macdonald Hatchery is provided by Noosa Shire Council and Queensland Department of Primary Industries. Additional funding for the period 1998-2001 has been provided through a Natural Heritage Trust grant. Successful operation of the hatchery relies heavily on volunteer labour.

Only one other privately owned hatchery currently has a licence to hold and produce Mary River cod. The Queensland Fisheries Management Authority has temporarily halted cod production by other hatcheries so as to protect wild stocks against depletion from broodstock collection. Fewer producers also make it a relatively simple task to manage the production of cod according to strict genetic guidelines.

Hatchery produced cod fingerlings have been stocked into south-east Queensland impoundments since 1983 (Table 4, p.9). Approximately 94% of these stocked cod were produced at the Lake Macdonald Hatchery. Riverine stocking of cod commenced in 1998, with approximately 39 000 fingerlings released at 42 sites in the Mary River system. Again, the vast majority of these were produced at Lake Macdonald. It is planned to continue to stock both riverine locations and impoundments with cod.

A summary of the breeding techniques used at the Lake Macdonald Hatchery are outlined below.

Breeding techniques

Preparation for spawning

Mary River cod are allowed to spawn naturally in earthen ponds. Hormone-induced spawning has been trialed on several occasions, and has met with variable success. Hormone-induction allows more control over the spawning process than natural spawning, but subjects the broodstock to handling stresses. Further trials with hormone-induction are warranted.

In April, ponds to be used for spawning are drained and allowed to dry. Spawning pipes are fitted with removable liners and placed in the pond. Ponds are filled with water from Lake Macdonald, and pairs of cod selected and introduced into the pond. Fights among pairs often break out as they establish new territories in the pond, and deaths have resulted. Fighting can be minimised by introducing fish into the pond at the same time rather than staggering introductions, as some fish will quickly lay claim to the whole pond if allowed.

Convenience and simplicity has dictated that pieces of fish flesh form the bulk of the diet of broodstock, although other items including squid, marine crustaceans, and frozen day-old chickens have been tried at times. The high variability in quantity and quality of eggs produced between individuals and between seasons suggests that an investigation into conditioning of broodstock is warranted. It is likely that an improved feeding regime would help ensure optimal condition of broodstock, which may then be translated into production of more eggs of high quality.

Since 1997, all cod broodstock have been individually marked with passive-integrated-transponder (PIT) tags. This allows accurate record keeping of length, weight, disease or injury management and breeding performance from year to year.

Spawning and egg management

As soon as eggs are detected in the spawning pipes (either by a diver, or by observation from the bank), the liner carrying the eggs is removed to a trough of running water in the hatchery. The liner is cut into smaller pieces which are then suspended in the water. Any clumps of eggs are gently broken up in the trough and dead eggs removed. The eggs are given a daily formalin bath (1 ppt for 30 minutes) to control fungus, and any dead eggs removed.

Fungal outbreaks have occurred on egg masses left in ponds for several days, so it is of vital importance that detection and removal of eggs from the ponds occurs as soon as possible after spawning. An improved method of egg detection and removal is needed to minimise fungal disease.

Water is circulated to the troughs via three 5 000 l tanks with thermostatically controlled heaters, and partial water changes are made at frequent intervals. Dissolved oxygen and ammonia levels are monitored daily. Both filtered water from Lake Macdonald and dechlorinated water from the domestic supply are used.

Larval management

Larvae begin to feed on brine shrimp produced in the hatchery and zooplankton from outdoor ponds around 5-7 days after hatching. Once feeding has commenced, the larvae are given a prophylactic salt bath (10 ppt for 30 minutes) every three days.

Larvae are on-grown to the desired stocking size either in outdoor ponds or in tanks and troughs indoors. Transfer to outdoor ponds occurs at 3-6 weeks of age, where the larvae rely largely on a cultured plankton bloom for food. High mortalities often occur in ponds due to predatory birds and insects and other identified causes. Indoor grow-out methods are still being developed, and early results are promising. Losses through predation are nil (apart from some cannibalism), and diseases and other problems with larval growth or health can be more easily detected and addressed. Harvest of larvae from indoor tanks is much easier and potentially less stressful to the fish than from outdoor ponds. The main problem with indoor rearing to date has been relatively slow growth of larvae. This should be overcome as optimum stocking densities and feeding regimes are determined.

Harvesting and stocking

Prior to 1998, Mary River cod fingerlings were harvested and stocked out when their total length reached approximately 50 mm (usually around ten weeks after hatching). This size is a standard requirement of the DPI Recreational Fisheries Enhancement Program. With the commencement of riverine stocking for conservation purposes in 1998, it was decided to reduce the stocking size to between 30 and 40 mm. Harvesting the fingerlings at this smaller size generally means that a greater number are available for stocking (as the longer a fingerling is held in the hatchery, the greater it's chance of succumbing to disease, predation or other mortality). Stocking fish at the smaller size provides a greater opportunity for natural selection (as opposed to 'hatchery selection') to operate. Fingerlings that are to be stocked in impoundments to enhance the recreational fishery are still grown to 50 mm as it is thought that the larger size provides better protection from predation.

Harvesting from outdoor ponds involves draining the pond and netting the fingerlings from a concrete sump. The process can be slow, muddy, and made difficult by large numbers of tadpoles and insect larvae which must be sorted from the fingerlings. Fingerlings raised indoors are simply netted from their tank or trough after lowering the water level. Transport of fingerlings to the stocking site is done either in large aerated carriers, or in oxygenated plastic bags.

Riverine stocking sites are selected for their apparent capacity to support the establishment of a new population. This determination is based on a visual assessment of the available habitat both in terms of quantity and condition. Highly degraded habitats, or small areas of habitat obviously isolated from other suitable areas, are avoided. The approach to stocking has been to select a reach of stream and stock fingerlings throughout. In some cases, this has included whole tributaries - in other cases, only a stretch of less than 1 km adjacent to the main river has been stocked. DPI plan to monitor the success of stockings by regular sampling at selected locations.

Genetic guidelines for the Mary River cod breeding program

Captive-breeding of Mary River cod has proceeded over the past fifteen years without clear guidelines to ensure the long-term genetic integrity of the fish produced. As the focus of the breeding program has now changed from recreational enhancement to conservation and recovery, it is a high priority that fingerlings are produced according to strict genetic guidelines (Allendorf & Ryman 1987; Brown 1987). New breeding and restocking guidelines for Mary River cod are based on those employed in the trout cod program in Victoria and New South Wales (Douglas et. al 1994).

Broodstock collection

Mary River cod broodstock are collected from as wide a geographic range as possible. This strategy is considered appropriate for a species that has suffered a contraction in range and abundance, and for which the genetic variability within and between remnant populations is unknown (Brown, 1987). It is unlikely that significant genetic differences have become established across the range of the cod, as any isolation of populations is likely to be a relatively recent event. However, collection of brood fish from a wide area will help ensure that any variability that does exist among remnant cod populations will be represented in the breeding program. New broodstock are sought each year following the breeding season.

Broodstock number

A target of 200 broodfish has been set for native fish propagation programs where stock rehabilitation is the objective (Brown, 1987). This is considered adequate to represent the wild gene pool. Brown (1987) recommends that the 200 fish should be collected over a period of two minimum generation intervals of the species in question (eg. about ten years for Mary River cod), and regularly interchanged with hatchery fish. Allendorf and Ryman (1987) suggest that 25 males and 25 females represents an absolute minimum size for a founder population. Douglas et. al (1994) consider the 25-50 trout cod broodstock held at each of two facilities adequate to meet recommended genetic guidelines, provided they are regularly replaced with wild fish.

The current collection of Mary River cod broodstock (40-50 individuals between the two cod hatcheries) is probably adequate, as long as they are regularly replaced with wild stock.

Broodstock management

All cod broodstock are individually tagged with passive integrated transponder (PIT) tags for accurate record keeping. Tagging will also ensure that released broodstock are not subsequently re-introduced into the breeding program. Fish are paired roughly according to size, as aggressive encounters during spawning sometimes result in death, particularly of smaller individuals. A broodstock sex ratio of 1:1 is maintained if possible to maximise genetic variability of the progeny. Repeated matings between the same pair is avoided for the same reason.

Broodstock collected from areas where prior stocking has not occurred are kept separate from those collected in stocked areas (eg. Lake Macdonald). This is to minimise the chance of inbreeding. The progeny of broodstock collected from stocked areas are not used in the riverine stocking program, but are stocked in impoundments outside the Mary River system.

Stocking

Prior to stocking, fingerlings from as many different spawnings as are available are mixed. A minimum of five spawnings is recommended in order to represent 95% of the genetic variation in the base population, although rare alleles might be excluded (Brown, 1987). Fingerlings are not released into areas containing known remnant populations where they could swamp rare alleles. It is planned to stock sites for at least four consecutive years so as to maximise the genetic variability of the stocked population, and to quickly establish a broad age distribution.