Understanding the ecological impacts of an introduced species is an essential component of pest management. This project examined the ecological impacts of the Eastern gambusia (Gambusia holbrooki) by integrating surveys and experimental work in natural billabong systems throughout the MDB. The specific objectives of the project were to:
- review current knowledge of the impacts of Eastern gambusia on native fishes of the MDB,
- provide information on the response of native fish communities following the reduction of Eastern gambusia populations,
- provide a framework to evaluate the feasibility and effectiveness of such control actions, and
- form a template for evaluating control options for other alien fishes across the MDB.
Review of the literature of the impacts of Eastern gambusia on native fishes of the MDB identified that 16 of 37 native species have major habitat or diet (or both) overlaps with Eastern gambusia. The most significant overlaps were with small bodied species, for example, Glassfish, Pygmy-perches, Rainbowfishes, Hardyheads, Gudgeons and Australian smelt. Based on these findings, it was thought that Eastern gambusia is likely to have contributed to the decline (in distribution and/or abundance) of the Olive perchlet, Southern pygmy-perch, Murray-Darling rainbowfish and Purple-spotted gudgeon.
An assessment of wetland communities throughout the mid-Murray region of the MDB found that Carp gudgeon and Eastern gambusia were the dominant species in both abundance and distribution. The results of the survey suggest that Eastern gambusia do not have a negative influence on abundances of the more common native species (eg. Carp gudgeon, Flat-headed gudgeon). This is most likely due to the generalist nature of these species, enabling their co-existence.
There was a negative effect between Eastern gambusia abundance and body condition of juveniles of several native species, indicating that as gambusia became more abundant, many native fish species became less healthy.
Researchers removed gambusia from several small isolated billabongs to observe how native fish would respond. The results of the removal trial indicate that reductions of Eastern gambusia abundances will result in some improvements to small-bodied native fish populations, though these effects may be even more pronounced in billabongs with simple habitats and containing species with selective diets. During this trial, astonishingly; a few individual Eastern gambusia were able to re-establish populations of thousands within three or four months.
The study also examined the cost-effectiveness and logistics of Eastern gambusia removal, and concluded that the highest benefits per dollar invested were achieved in locations where simple, uncomplex habitats that did not connect to other gambusia populations regularly, and contained high ecological value.
Implications for native fish
This project provides fundamental ecological information to assist in the management of Eastern gambusia. This project provides managers with some options to assess the cost benefit of Eastern gambusia removal for a range of habitat scenarios. This will result in better targeted efforts to control this pest species and maximise benefits to native fish populations. To find out more about removing Eastern gambusia you can access the Department of Environment, Water, Land and Planning Fact Sheet by following this link. There is more information about Eastern gambusia on this website also provided through DEWLP.
Tonkin, Z., Macdonald, J., Ramsey, D., Kaus, A., Hames, F., Crook, D. and King, A. 2012. Assessing the recovery of fish communities following removal of the introduced eastern gambusia, Gambusia holbrooki. Arthur Rylah Institute for Environmental Research Technical Report Series No. 232. Department of Sustainability and Environment, Heidelberg, Victoria.
Alabaster, J. and Stott, B. 1978. Swimming activity of perch, Perca fluviatilis L. Journal of Fish Biology 12: 587-591.
Ansell, D. and Jackson, P. 2007. Emerging issues in Alien Fish Management in the Murray-Darling Basin: Statement, recommendations and supporting papers. Canberra, Murray-Darling Basin Commission.
Agtrans Research (2005). Review of progress on invasive species. Final report to the Department of Environment and Heritage, Brisbane, Queensland.
Alcaraz, et al 2008. Salinity mediates the competitive interactions between invasive mosquitofish and an endangered fish. Oecologia 155, 205-213.
Alcaraz, C. and García-Berthou, E. (2007). Life history variation of invasive mosquitofish (Gambusia holbrooki) along a salinity gradient. Biological Conservation 132, 83-92.
Arthington, A. H. (1991). Ecological and genetic impacts of introduced and translocated freshwater fishes in Australia. Canadian Journal of Fisheries and Aquatic Sciences 48, 33-43.
Arthington, A. H. and Lloyd L. N. (1989). Introduced Poeciliids in Australia and New Zealand. In Ecology and evolution of livebearing fishes (Poeciliidae). (Meffe, G. K. and Snelson, F. F. Jnr., Eds.), pp. 333-348, Prentice-Hall, Inc., New Jersey.
Arthington, A. H. and Marshall, C. J. (1999). Diet of the exotic mosquitofish, Gambusia holbrooki, in an Australian lake and potential for competition with indigenous fish species. Asian Fisheries Science 12, 1-16.
Becker, A., Laurenson, L. J. B., Jones, P. L. and Newman, D. M. (2005). Competitive interactions between the Australian native fish Galaxias maculatus and the exotic mosquitofish Gambusia holbrooki, in a series of laboratory experiments. Hydrobiologia 549, 187-196.
Breen, A. (2000). Density dependent interference competition between the exotic poeciliid Gambusia holbrooki (Girard, 1859) and the Australian native melanotaeniid Rhadinocentrus ornatus (Regan, 1914). Unpublished Honours thesis, Southern Cross University, Lismore.
Chapman, P. and Warburton, K. (2006). Postflood movements and population connectivity in gambusia. Ecology of Freshwater Fish 15, 357-365.
Conte, S. (2001). An investigation of density-dependant interference competition between the exotic poeciliid Gambusia holbrooki (Girard, 1859) and the Australian native fish Hypseleotris galii (Ogilby, 1903). Unpublished Honours thesis, Southern Cross University, Lismore.
Courtenay, W. R. J. and Meffe, G. K. (1989). Small fishes in strange places: a review of introduced poeciliids. In Ecology and evolution of livebearing fishes (Poeciliidae). (Meffe, G. K. and Snelson, F. F. Jnr., Eds.), pp. 319-332. Prentice-Hall, Inc., New Jersey.
Cronin, A. (2001). Aggressive interaction by the introduced poeciliid Gambusia holbrooki on two native freshwater species, the firetail gudgeon Hypseleotris galii and the Oxleyan pygmy perch Nannoperca oxleyana. Unpublished Honours thesis, Southern Cross University, Lismore.
Elkington, S. (2004). Eradication of Gambusia (Gambusia affinis) and koi carp (Cyprinus carpio) from the Nelson/Marlborough Conservancy. Department of Conservation Te Papa Atewhai, Nelson.
Freeman, R. (2007). Tamar Estuary, Gambusia Eradication. Internal Report, Inland Fisheries Service, Hobart.
García-Berthou, E. (1999). Food of introduced mosquitofish: ontogenetic diet shift and prey selection. Journal of Fish Biology 55, 135-147.
Gill, H. S., Hambleton, S. J. and Morgan, D. L. (1999). Is the mosquitofish, Gambusia holbrooki (Poeciliidae), a major threat to the native freshwater fishes of south-western Australia? In Proceedings of the 5th Indo-Pacific Fish Conference, 1997. (Seret, B. and Sire, J.-Y. Eds.), pp. 393-403. Societé Française d’Ichthyologie, Paris.
Goodsell, J. A. and Kats, L. B. (1999). Effect of introduced mosquitofish on Pacific treefrogs and the role of alternative prey. Conservation Biology 13, 921-924.
Howe, E., Howe, C., R., L. and Burchett, M. (1997). Impact of the introduced poeciliid Gambusia holbrooki (Girard, 1859) on the growth and reproduction of Pseudomugil signifer (Kner, 1865) in Australia. Marine and Freshwater Research 48, 425-434.
Hurlbert, S. H., Zedler, J. and Fairbanks, D. (1972). Ecosystem alteration by Mosquitofish (Gambusia affinis) predation. Science 175, 639-641.
Karolak, S. (2006). Alien Fish in the Murray-Darling Basin. MDBC publication No. 03/06. Murray- Darling Basin Commission, Canberra.
Keane, J. P. and Neira, F. J. (2004). First record of mosquitofish, Gambusia holbrooki, in Tasmania, Australia: stock structure and reproductive biology. New Zealand Journal of Marine and Freshwater Research 38, 857-867.
Keller, K. and Brown, C. (2008). Behavioural interactions between the introduced plague minnow Gambusia holbrooki and the vulnerable native Australian ornate rainbowfish Rhadinocentrus ornatus, under experimental conditions. Journal of Fish Biology 73, 1714-1729.
Komak, S. and Crossland, M. R. (2000). An assessment of the introduced mosquitofish (Gambusia affinis holbrooki) as a predator of eggs, hatchlings and tadpoles of native and non-native anurans. Wildlife Research 27, 185-189.
Koster, W. M. (1997). A study of the interactions between dwarf galaxias (Galaxiella pusilla), southern pygmy perch (Nannoperca australis) and eastern Gambusia (Gambusia holbrooki). B. Sc. Honours thesis, Deakin University, Clayton.
Laha, M. and Mattingly, H. T. (2007). Ex situ evaluation of impacts of invasive mosquitofish on the imperilled Barrens topminnow. Environmental Biology of Fishes 78, 1-11.
Macdonald, J. and Tonkin, Z. (2008). A review of the impact of eastern gambusia on native fishes of the Murray-Darling Basin. Arthur Rylah Institute for Environmental Research, Department of Sustainability and Environment, Heidelberg, Victoria. Murray-Darling Basin Authority Publication No 38/09, Canberra.
Pyke, G. H. (2005). A review of thP biology of Gambusia affinis and G. holbrooki. Reviews in Fish Biology and Fisheries 15, 339-365.
Pyke, G. H. (2008). Plague minnow or mosquito fish? A review of the biology and impacts of introduced Gambusia species. Annual Review of Ecology and Systematics 39, 171-191.
Rehage, J. S., Barnett, B. K. and Sih, A. (2005). Foraging behaviour and invasiveness: do invasive Gambusia exhibit higher feeding rates and broader diets than their non-invasive relatives? Ecology of Freshwater Fish 14, 352-360.
Rowe, D. K., Smith, J. P. and Baker, C. (2007). Agonistic interactions between Gambusia affinis and Galaxias maculatus: implications for whitebait fisheries in New Zealand rivers. Journal of Applied Ichthyology 23, 668–674.
Warburton, K. and Madden, C. (2003). Behavioural responses of two native Australian fish species (Melanotaenia duboulayi and Pseudomugil signifer) to introduced Poeciliids (Gambusia holbrooki and Xiphophorus helleri) in controlled conditions. Proceedings of the Linnean Society of New South Wales 124, 115-123.
Warburton, K., Retif, S. and Hume, D. (1998). Generalists as sequential specialists: diets and prey switching in juvenile silver perch. Environmental Biology of Fishes 51, 445-454.
Webb, C. and Joss, J. (1997). Does predation by the fish Gambusia holbrooki (Atheriniformes: Poeciliidae) contribute to declining frog populations. Australian Zoologist 30, 316-324.
Latest posts by Finterest (see all)
- Population models help assess risk for a threatened species - December 3, 2018
- Zeb Hogan presents Monsterfish Free Public Lecture - November 22, 2018
- Climate change, stream flows and recruitment – is there a connection for Australian Bass? - November 19, 2018