201 research outputs found
Summary of management policies and fisheries regulations for Murray Cod in the Murray-Darling Basin
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Managing potential impacts of reservoir enlargement on threatened Macquaria australasica and Gadopsis bispinosus in southeastern Australia
No full textEnlargement of a domestic water supply reservoir on the Cotter River in southeastern Australia (4 to 78 Gl) includes an inundation zone that contains 2 threatened fish species, Macquarie perch Macquaria australasica and two-spined blackfish Gadopsis bispinosus. The enlarged reservoir will be 50 m deeper and impound an additional 4.5 km of river and thus poses a number of potential threats to these fish species. The majority of threats relate to the inundation zone or upstream environments, as downstream environments have been degraded by significant flow alterations from the existing Cotter Dam and 2 upstream dams. Threats include the loss of refuge habitat and associated increased predation, loss of preferred food sources, invasion and expansion of alien fish populations, loss of spawning habitat (or access to it), and the introduction of disease. To minimise or mitigate these threats, a collaborative and comprehensive research and management program is underway involving participation from the water utility and various universities and government agencies. Funding by the water utility of an independent senior fisheries scientist, establishment of a stakeholder steering group, independent peer review processes, and dedicated staff within the design and construction alliance are intended to ensure fish requirements are considered in dam design, construction, and operation. The establishment of an independent, collaborative science-driven process, coupled with the establishment of a long-term monitoring program in an adaptive management framework is a model for other infrastructure projects worldwide, particularly those that threaten riverine fish
Alien fishes in Australia
No full textData, computer code, and supplemental results from: García-Díaz, P., Kerezsy, A., Unmack, P.J., Lintermans, M., Beatty, S.J., Butler, G.L., Freeman, R., Hammer, M.P., Hardie, S., Kennard, M.J., Morgan, D.L., Pusey, B.J., Raadik, T.A., Thiem, J.D., Whiterod, N., Cassey, P. & Duncan, R.P. (2018). Transport pathways shape the biogeography of alien freshwater fishes. Diversity and Distributions, https://onlinelibrary.wiley.com/doi/abs/10.1111/ddi.12777Date last modified:22/05/2018Date uploaded: 04/10/2017Please refer to the README file for further information</div
Molecular taxonomy of Australia’s endemic freshwater crayfish genus Euastacus (Parastacidae), with reference to priority 2019-20 bushfire-impacted species.
No full textEuastacus is the most threatened genus of endemic Australian freshwater crayfish, with 80% of its species considered threatened and listed under International Union for Conservation of Nature (IUCN) threat categories (Furse and Coughran 2011; Richman et al. 2015). The 2019‒ 20 Australian megafires in eastern Australia were predicted to have impacted 22 species of Euastacus (or 40% of described species) (Legge et al. 2021a; Legge et al. 2021b).No Full Tex
Corrigendum to:Recolonization by the mountain galaxias Galaxias olidus of a montane stream after the eradication of rainbow trout Oncorhynchus mykiss (Marine and Freshwater Research 51:8 (801))
No full textMethods. Rotenone treatment: a 5% rotenone emulsion was added to the stream section. The estimated final concentration of rotenone in the stream has been wrongly reported as ~1 part per million. This should read ~0.05 parts per million
Recolonization by the mountain galaxias Galaxias olidus of a montane stream after the eradication of rainbow trout Oncorhynchus mykiss
No full textA possible false negative: lack of evidence for trout predation on a remnant population of the endangered Macquarie perch, Macquaria australasica, in Cotter Reservoir, Australia
No full textTo investigate possible predation on a remnant population of the endangered Macquaria australasica in Cotter Reservoir, ACT, Australia, stomach content analysis was conducted on 63 rainbow trout Oncorhynchus mykiss and 24 brown trout Salmo trutta. Both predators were found to be piscivorous, with the frequency of piscivory generally increasing with body size. Goldfish Carassius auratus were the only fish species identified in stomach contents. That gape-limitation prevented trout from feeding on juvenile M. australasica was eliminated as a possibility based on: (1) the body depth of prey and the mouth-size of predators; and (2) evidence that another species of similar dimensions was ingested by trout. Whether or not trout predation on M. australasica is an important process in Cotter Reservoir remains to be clarified. Juvenile M. austalasica do not reside in the parts of the reservoir from which most trout were actually sampled in the current study. Therefore, it is proposed that the lack of evidence for predation on M. australasica is potentially a false-negative result.No Full Tex
Radio-tagging and tracking of translocated trout cod (Maccullochella macquariensis: Percichthyidae) in an upland river
No full textRadio-tracking provides an effective means of studying the spatial ecology of threatened fishes where almost inaccessible habitats and species rarity render conventional mark-recapture methods impractical. Initially, validation of an effective radio-tagging method is required; in the present study, an aquaria trial based on nine hatchery-reared, adult male Maccullochella maquariensis (Percichthyidae) was conducted. Fish resumed feeding within days of being internally implanted with a radio-tag, and tag rejection was not observed (0%, n = 9) based on a 2-month observational period. Following release into an upland stream, individual-specific movements resulted in upstream (n = 1) and downstream (n = 6) dispersal as well as fidelity to the release site (n = 2) at the completion of the study. Individuals established small home-ranges (mean length of river used by an individual per diel period ranged from 47 to 292 m) and were most active in the early morning and evening (n = 6). Complete survivorship of individuals bearing active radio-transmitters (n = 8) was recorded up until 4 months after release. However, an estimated zero or one individual was alive when the last active radio-tag expired 11 months after release (n = 8). The present study highlights the use of radio-tracking in monitoring the dispersal and survivorship of small numbers of hatchery-reared threatened fish released into natural habitats as part of species re-introduction programs
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