Acknowledgements V Summary VI 1 General introduction 1 1 Barred Galaxias 1




НазваниеAcknowledgements V Summary VI 1 General introduction 1 1 Barred Galaxias 1
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4.2.2 Mitochondrial DNA analysis 32

4.3 Results 35

4.3.1 Microsatellite analysis 35

4.3.2 Mitochondrial DNA analysis 35

4.4 Discussion and recommendations 38

References 40

Appendix 1 Environmental variables recorded at sampling sites 43


List of tables and figures

Tables

Table 1. Details of the 61 potential Barred Galaxias translocation sites surveyed and their translocation suitability. 11

Table 2. Translocation and post-monitoring schedule. 22

Table 3. Barred Galaxias maturation categories (modified from Pollard 1972). 25

Table 4. Number (n) and size (average length/weight [range] mm/g) of Barred Galaxias collected from
Kalatha and Luke Creeks and those translocated to Shaw Creek and Taponga River. 26

Table 5. Number (n) and size (average length/weight [range] mm/g) of Barred Galaxias collected at source
and translocation creeks during three and six month post-monitoring events. 27

Table 6. The 12 microsatellite markers used in population genetic assessments of Barred Galaxias. 35

Table 7. Genetic statistics for Barred Galaxias assessed per location. 36

Figures

Figure 1. Barred Galaxias, Galaxias fuscus. 1

Figure 2. Distribution of Barred Galaxias, Mountain Galaxias and trout within the study area. 5

Figure 3. Decision support framework for assessing the suitability of potential Barred Galaxias translocation sites. 6

Figure 4. Electrofishing the upper Goulburn River (left) and a Rainbow Trout found in Spring Creek (right). 7

Figure 5. Decision support framework for assessing the presence of instream barriers. 8

Figure 6. Evelyn Falls on Koala Creek, which prevents upstream movement of trout. 8

Figure 7. Examples of survey sites: tributary of Big River (left); and Shaw Creek (right). 9

Figure 8. Distribution of the 61 sites surveyed including their assessment result and fish species recorded. 10

Figure 9. Site of the source population for the Barred Galaxias translocation trial in Kalatha Creek (left) and
Luke Creek (right). 19

Figure 10. Location of Kalatha, Luke and Shaw creeks and Taponga River in the Goulburn River catchment, Victoria. 20

Figure 11. Barred Galaxias translocation site on Shaw Creek (site FT024) (left) and Taponga River (site FT033) (right). 21

Figure 12. Collecting Barred Galaxias for translocation from Luke Creek using electrofishing. 22

Figure 13. ARI staff transporting Barred Galaxias. 23

Figure 15. Adult and larval Barred Galaxias release and range expansion (RE) reaches at Shaw Creek (upper)
and Taponga River (lower). 24

Figure 16. Releasing translocated adult (left) and larval (right) Barred Galaxias into Taponga River. 24

Figure 17. Barred Galaxias collected during the six month post-monitoring event. 29

Figure 18. The 28 locations in the Goulburn River basin from which Barred Galaxias samples were
collected for genetic analysis. 33

Figure 19. Examples of locations where Barred Galaxias were collected: Taggerty River (left); Rubicon River (right). 34

Figure 20. Electrofishing for Barred Galaxias in Robertsons Gully near Marysville. 34

Figure 21. Relationships of the 12 mitochondrial DNA haplotypes for Barred Galaxias. 37


Acknowledgements

This project is No. 14 of the program ‘Rebuilding Together’ funded by the Victorian and Commonwealth government’s Statewide Bushfire Recovery Plan, launched October 2009.

We are grateful to everyone who assisted on this project. Mark Lintermans (University of Canberra), Iain Ellis (Murray Darling Freshwater Research Centre) and Neil Hyatt (Department of Primary Industries (DPI) Fisheries Victoria) provided expert advice on translocation procedures. Dean Hartwell, Peter Fairbrother, Daniel Stoessel, David Bryant, Lauren Dodd, Ruth Lennie and Fern Hames (all Department of Sustainability and Environment, Arthur Rylah Institute (DSE ARI)) provided field or laboratory assistance. Regional DSE staff, namely, Bill Twichett, Dale Young, Mike Lauder, Jennifer Sutherland and Gillian Pannan, and Ian Roche (Parks Victoria) and Brett Weinberg (Lake Mountain Resort) provided advice on potential site locations and access. The translocation application was approved by DPI Translocation Evaluation Panel. Andrew Weeks, Adam Miller, and Anthony van Rooyen (Cesar) undertook the genetic analysis. Funding to rear the larval Barrred Galaxias, which were used in the translocation trial (Chapter 3), was provided separately under the Caring for Our Country (CfoC) Bushfire Recovery Program. Paul Reich and Daniel Stoessel (DSE ARI), and Stephen Smith and Stephen Platt (DSE) are thanked for reviewing earlier versions of this document. This work was conducted under the following permits: FFG/National Parks research Permit 10005451, Fisheries Research Permit RP827, DSE Animal Ethics approvals AEC 07/24 and 10/21 and DSE/DPI Translocation of Live Aquatic Organisms in Victoria approval PM/21/0002.


Summary

Barred Galaxias (Galaxias fuscus) is a small, nationally endangered freshwater fish endemic to the upper headwaters of the Goulburn River catchment in central Victoria, Australia. Its habitat, from Lake Mountain to Mount Disappointment, was burnt during the 2009 Black Saturday bushfires. This represents 45 % of the known range of the species and many populations in this area suffered from direct and indirect post-fire affects.

This study aimed to improve the recovery of post-fire affected Barred Galaxias populations and reduce their overall extinction risk by establishing new populations in suitable streams within their former range. We identified and assessed potential Barred Galaxias translocation sites and chose two suitable catchments as recipients for trial translocations. Fish from two source populations were reintroduced into these catchments and post-translocation monitoring occurred twice in the following six month period to determine the short-term success of the translocation.

Two hundred and sixteen potential sites were identified and mapped, mostly within upper reaches of the Yea, Acheron-Taggerty, Rubicon and Big River systems. Of these sites, 61 were surveyed and assessed for suitability based upon obvious habitat threats (e.g. fire and logging impacts, hydrology), the presence of fish, the existence of a physical barrier to fish movement, and catchment size. Only six sites in four upland catchments were immediately suitable for the translocation of Barred Galaxias. Two of these, namely Shaw Creek and the upper Taponga River, were selected for trial translocations. Of the remaining surveyed sites, 49 require further work before being suitable for Barred Galaxias translocation (e.g. further surveys to identify the location of physical barriers or installation of a physical barrier and upstream removal of trout). Six other surveyed sites were deemed unsuitable for translocation because they had no water or contained native fish species. Information collected during these surveys will be useful to inform future translocations of Barred Galaxias.

In late November/early December 2010, Barred Galaxias sourced from Luke Creek were translocated to Taponga River and Barred Galaxias sourced from Kalatha Creek were translocated to Shaw Creek. The source and translocated Barred Galaxias populations were monitored in March and June 2011 to determine their survival and, for translocated populations only, range expansion. The source populations appeared to be unaffected by the removal of individuals because fish were present within all reaches in similar abundances and size classes to those recorded during the initial collection period, and individuals displayed signs of reproductive development. In the short-term, we considered that the translocations were successful because fish survived and expanded in range at the translocated sites, they were in good physical condition and their maturation stages suggested they are likely to reproduce during the 2011 breeding season.

Post-fire management of Barred Galaxias highlighted the need to improve our understanding of the population genetics of the species across its range to effectively manage, conserve and recover populations. As a sub-project to establishing new populations for fire-affected Barred Galaxias, we conducted a comprehensive population genetic analysis throughout its current distribution to determine population genetic diversity and differentiation, and gene flow.

Tissue samples were collected from Barred Galaxias for genetic analysis and forty microsatellite markers were identified and trialled, of which, 12 were selected for use in the population genetic assessments. In total, 568 Barred Galaxias individuals were genotyped at 12 polymorphic microsatellite loci. Genetic variation within populations was found to be extremely low, with some displaying no genetic variation between individuals. Genetic variation between populations was high, indicating limited gene flow over broad distances within and between river systems. Also, 94 Barred Galaxias individuals, collected from 26 locales, were studied in a phylogeographic assessment. Twelve haplotypes were revealed with most individuals belonging to two common haplotypes. Two major evolutionary clades were found. However there were weak phylogeographic patterns.

This population genetic study provides a valuable spatial framework for effective conservation management of Barred Galaxias and a foundation for future population genetic monitoring. The genetic factors identified, including low levels of genetic variation, high population structuring and limited gene flow, coupled with small population sizes and ongoing threats, such as trout predation and competition and stochastic environmental impacts, suggest Barred Galaxias populations are at high risk of extinction without effective management intervention. Translocations, genetic augmentation and supplementing populations with captive bred individuals are essential recovery actions that can be undertaken using this genetic data to strategically guide these management actions with the overall aim of enhancing the genetic diversity of populations, whilst maintaining the species’ genetic integrity.

Future management actions and research are recommended to facilitate additional Barred Galaxias translocations and ensure the long-term persistence of the translocated populations, including:

• Install a second physical barrier at Taponga River upstream of the 15 Mile Road crossing to secure the translocated Barred Galaxias population;

• Conduct a cost/benefit analysis on the expense of conducting management works (i.e. physical barrier installation, trout removal) compared to further surveys for physical barriers at identified fishless sites and/or new translocation sites;

• Perform physical barrier surveys on the 24 identified fishless sites to potentially add to the list of sites suitable for immediate translocation;

• Install physical barriers and remove trout from upstream reaches at 19 sites to render them suitable for immediate Barred Galaxias translocation;

• Any future assessment of translocation site suitability should include measurements of water permanency, assessment of the amount of appropriate spawning habitat, and site accessibility;

• Continue monitoring the translocated Barred Galaxias populations to assess their long-term survival, establishment (breeding and recruitment), range expansion and genetic viability. This data will inform whether future population supplementation or habitat modification is necessary to sustain the population or aid successful natural recruitment;

• Undertake genetic analysis of translocated populations one, five and ten years post-establishment, with comparison with the genetic diversity of the founder individuals;

• Undertake captive breeding of Barred Galaxias to supplement natural populations when required, e.g. to boost population sizes and enhance population diversity;

• Undertake ongoing monitoring of all populations, particularly those with small populations sizes, those where translocations have occurred, those containing captive bred individuals and those under direct threat e.g. from drought and fire impacts, and trout predation;

• Mitigate threats to all populations, including trout prodations, sedimentation, dewatering, etc.

• Undertake additional translocations, guided by the results of the population genetics analysis, by mixing populations and creating new populations; and,

• Continue engaging and educating stakeholders regarding the significance of Barred Galaxias conservation and their key threats, including potential impacts of human-assisted trout dispersal.


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