ASFB Home > 2003 > Biological Invasions: Consequences for Parasites, Pathogens, Emerging Diseases, and Fisheries in the Marine Environment.

Management actions for the critically threatened native fish the lowland longjaw galaxias (Galaxias cobitinus)

Richard Allibone¹, Peter Ravenscroft², Ross Dungey³, Murray Neilson⁴, Simon Elkington⁵

¹ Biodiversity Recovery Unit, Department of Conservation, PO Box 10420, Wellington New Zealand
² Otago Coastal Area Office, Department of Conservation, PO Box 5244, Dunedin, New Zealand
³ Ross Dungey Consulting, 109 Benhar Road, R.D. 2, Balclutha, New Zealand
⁴ Otago Conservancy, Department of Conservation, PO Box 5244, Dunedin, New Zealand
⁵ Twizel Area Office, Department of Conservation, Private Bag, Twizel, New Zealand
Email: rallibone@doc.govt.nz

The lowland longjaw galaxias (Galaxias cobitinus) was described as a new species of galaxiid in 2002 from specimens collected from the Kauru River, North Otago. Survey data indicated the species was limited to c. 6 km of the Kauru River in an area prone to drought and utilised for water and gravel abstraction. A second population known from single preserved galaxiid from the Hakataramea River was after subsequent resurveys thought to be extinct. Severe drought in North Otago in the summer of 2001/02 reduced the Kauru River to a few small isolated pools and post drought surveys indicated c. 250 lowland longjaws survived in the known occupied reach. The species was given the highest threatened species ranking by the Department of Conservation and recovery action implemented to access threats, gain an understanding of the species’ biology and habitat requirements and to survey for further populations. Survey results have located three new populations in the upper Waitaki River and extended the known range in the Kauru River catchment from 6 km of river to over 14 km. Habitat use studies have defined habitat preferences for larval and adult fish and biological studies have shown that the fish is essentially an annual species and highly vulnerable to population decline in years of high mortality. Further investigations now seek to understand the groundwater, surface water, water abstraction relationships and the impact of gravel mining in the Kauru River so that long term management strategies can be developed.

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