Nomination no.
833
FLORA AND FAUNA GUARANTEE - SCIENTIFIC ADVISORY COMMITTEE
PRELIMINARY RECOMMENDATION ON A NOMINATION FOR LISTING
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Dargo Galaxias – Galaxias sp. 6
Date of consideration:
2 February, 18 May, 16 August, 29 October 2012; 11 February, 9 May, 16 August 2013;
29 January, 30 April, 24 July 2014.
File No.: FF/54/3428
Validity:
The nomination is for a valid item.
Prescribed Information:
The prescribed information was provided.
Name of the Nominator is adequately provided.
Name of the item is adequately provided.
The nominated taxon is recognised as a distinct and new species and has been accepted as a valid taxon by Museum Victoria.
Type specimens for the taxon have been lodged in the fish collection of the Museum Victoria (NMV) and the Australian
Museum, Sydney (AMS).
Dargo Galaxias (Galaxias sp. 6 as described by Raadik in press) is a recently identified new species as a result of a taxonomic
revision of the Galaxias olidus species complex (Raadik 2011, Adams et al. 2014), which is being formerly described (Raadik
in press). The nominated item has been accepted by the SAC as a valid taxon because a description, accepted by a refereed
scientific journal, has been viewed by the SAC and voucher specimens have been lodged in the Museum of Victoria. The
taxon can be distinguished from all other members in the complex by a distinctive combination of multiple allozymic (genetic)
and morphological (morphometric and meristic) differences (Raadik 2011, Adams et al. 2014). It belongs to the Southern
Hemisphere family Galaxiidae which are elongate, generally cylindrical to laterally compressed, scale-less freshwater fish.
Dargo Galaxias occurs in central Gippsland, is usually 70-80mm in length and is distinguished by a dark brown coloration,
shallow head, eye close to the front of the head and the dorsal fin set far back on the body.
Eligibility for listing as a taxon under the Flora and Fauna Guarantee
The nominated item satisfies at least one criterion of the set of criteria prepared and maintained under Section 11 of the Flora
and Fauna Guarantee Act 1988, and stated in Schedule 1 of the Flora and Fauna Guarantee Regulations 2011.
Evidence that criteria are satisfied:
Criterion 1.2 the taxon is significantly prone to future threats which are likely to result in extinction
Evidence:
Brown Trout (Salmo trutta), a major predator of Dargo Galaxias, are currently present immediately below the
downstream extent of the population of Dargo Galaxias. They are currently unable to migrate upstream due to a set of
waterfalls which are an effective instream barrier. The effectiveness of waterfalls as a trout barrier can reduce
permanently or temporarily under certain conditions (e.g. erosion, landslip, timber debris, increased flows, etc.), allowing
trout to move further upstream, and even a small number of trout can breed and quickly establish a large population
upstream (Raadik, T.A., unpublished data). Therefore, the risk that trout invade and cause the extinction of Dargo
Galaxias is ever present. Further, Dargo Galaxias is restricted to one short section in the headwaters of a small creek in
the upper Dargo River system (Raadik 2011, Raadik and Nicol 2012, Raadik in press) and is therefore at risk of
extinction due to localised stochastic events: the species is unable to recolonise from another part of the catchment or
from nearby catchments.
Sub-criterion 1.2.1 the taxon is very rare in terms of abundance or distribution
Evidence:
Dargo Galaxias is restricted to one short section (4 km long and approximately 0.5–1.3 m wide) in the headwaters of a
small creek within the Alpine National Park in the upper Dargo River catchment. Widespread but unsuccessful sampling
has been conducted for this species at other sites (Raadik 2011, Raadik and Nicol 2012, Raadik in press).
Sub-criterion 1.2.2 the threat is currently operating and is expected to operate at a level in the future which is likely to result
in the extinction of the taxon.
Evidence:
The population of Dargo Galaxias is under constant threat from colonisation by introduced trout which, if it occurs, will
likely lead to the rapid extinction of the population due to predation. Further, as the population is small and restricted to
NOMINATION NO. 833
one location in a small alpine creek, the increased frequency of drought and bushfire under a Climate Change scenario,
including processes which increase instream sedimentation, are highly likely to result in the future extinction of the taxon.
The data presented on distribution and abundance are the result of reasonable surveys and provide clear evidence that the
taxon is rare in terms of abundance and distribution.
Additional Information
- Dargo Galaxias is considered ‘Critically Endangered’ in the most recent review of the DSE advisory list of vertebrate
fauna in Victoria (DSE 2013).
- Dargo Galaxias has been classified as ‘Critically Endangered’ by the Australian Society of Fish Biology’s threatened
fishes committee.
- As with many other headwater resident, non-migratory galaxiids Dargo Galaxias is thought to be highly susceptible to,
and to have been previously severely impacted by, predation from introduced salmonids, particularly Brown Trout.
Documentation
The information provided to the Scientific Advisory Committee (SAC) has been assessed. Based on the available evidence,
the SAC believes that the data presented are not the subject of scientific dispute and the inferences drawn are reasonable and
well supported.
SAC's Preliminary Recommendation
The SAC concludes that on the evidence available the nominated item is eligible for listing in accordance with Section 11(1) of
the Act because criterion 1.2 of the Flora and Fauna Guarantee Regulations 2011 has been satisfied. The Scientific Advisory
Committee also concludes that sub-criteria 1.2.1 and 1.2.2 have been satisfied.
The Scientific Advisory Committee therefore makes a preliminary recommendation that the nominated item be supported for
listing under the Flora and Fauna Guarantee Act 1988.
Relevant references:
Adams, M., Raadik, T.A., Burridge, C. and Georges, A. (2014) Global biodiversity assessment and hyper-cryptic species
complexes: more than one species of elephant in the room? Systematic Biology 63(4), 518-533.
DSE (2013) Advisory List of Threatened Vertebrate Fauna in Victoria - 2013. Department of Sustainability and Environment,
East Melbourne, Victoria. URL: http://www.depi.vic.gov.au
Raadik, T.A. (2011) Systematic revision of the Mountain Galaxias, Galaxias olidus Günther, 1866 species complex (Teleostei:
Galaxiidae) in eastern Australia. PhD Thesis, University of Canberra.
-------------- (in press) Fifteen from one: a revision of the Galaxias olidus Günther, 1866 complex (Teleostei, Galaxiidae) in
south-eastern Australia recognises three previously described taxa and describes 12 new species. Zootaxa
Raadik, T.A. and Nicol, M.D. (2012) Assessment of the post-fire status of the Dargo Galaxias (Galaxias sp. 6) affected by the
White Timber Spur fire, upper Dargo River system. Black Saturday Victoria 2009. Natural values fire recovery program.
Department of Sustainability and Environment, Heidelberg, Victoria.
Relevant internet information:
Galaxiids (Australian Museum) - http://australianmuseum.net.au/Galaxiids
Galaxiids (Fishes of Australia – online) - http://www.fishesofaustralia.net.au/search?q=galaxiidae
The galaxiid fishes of Australia (1981 paper)(Australian Museum)
http://australianmuseum.net.au/Uploads/Journals/17560/195_complete.pdf
Galaxiids (Department of Primary Industries, Victoria)
http://www.dpi.vic.gov.au/fisheries/recreational-fishing/catch-limits-and-closed-seasons/freshwater-scale-fish/galaxiids
Trout impacts on galaxiids (2006 paper)(Reviews in Fish Biology and Fisheries)
http://link.springer.com/article/10.1007%2Fs11160-006-9017-7
Endorsement by the Convenor of the Scientific Advisory Committee
Date
30 July 2014
SIGNED BY
____________________________
Assoc. Prof David Morgan
Convenor
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