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Narrandera, Australia

Rourke M.L.,Narrandera Fisheries Center | Teske P.R.,Macquarie University | Teske P.R.,Flinders University | Attard C.R.M.,Macquarie University | And 3 more authors.
Conservation Genetics Resources | Year: 2010

The Australian freshwater catfish (Tandanus tandanus) has suffered a decline in abundance and distribution, and stocking of wild populations with hatcherybred fish has been suggested to assist with population recovery. Here we describe the isolation and characterisation of eight microsatellite markers that may be used to assess population structure of T. tandanus in the wild to inform future stocking programs of any major genetic boundaries between populations. We tested the variability of the loci in 28-29 individuals from three populations of T. tandanus, as well in 24 individuals from a population representing an undescribed species. Expected heterozygosity for these loci ranged from 0.034 to 0.920 across the four populations. All loci successfully amplified in the three T. tandanus populations, while in the undescribed species one locus failed to amplify and three loci were monomorphic. © Springer Science+Business Media B.V. 2009. Source

Nock C.J.,Southern Cross University of Australia | Ovenden J.R.,Molecular Fisheries Laboratory | Butler G.L.,Grafton Aquaculture Center | Wooden I.,Narrandera Fisheries Center | And 2 more authors.
Journal of Fish Biology | Year: 2011

Microsatellite markers were used to examine spatio-temporal genetic variation in the endangered eastern freshwater cod Maccullochella ikei in the Clarence River system, eastern Australia. High levels of population structure were detected. A model-based clustering analysis of multilocus genotypes identified four populations that were highly differentiated by F-statistics (FST = 0· 09 - 0· 49; P < 0· 05), suggesting fragmentation and restricted dispersal particularly among upstream sites. Hatchery breeding programmes were used to re-establish locally extirpated populations and to supplement remnant populations. Bayesian and frequency-based analyses of hatchery fingerling samples provided evidence for population admixture in the hatchery, with the majority of parental stock sourced from distinct upstream sites. Comparison between historical and contemporary wild-caught samples showed a significant loss of heterozygosity (21%) and allelic richness (24%) in the Mann and Nymboida Rivers since the commencement of stocking. Fragmentation may have been a causative factor; however, temporal shifts in allele frequencies suggest swamping with hatchery-produced M. ikei has contributed to the genetic decline in the largest wild population. This study demonstrates the importance of using information on genetic variation and population structure in the management of breeding and stocking programmes, particularly for threatened species. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles. Source

Stoffels R.J.,CSIRO | Clarke K.R.,Plymouth Marine Laboratory | Rehwinkel R.A.,La Trobe University | Rehwinkel R.A.,Narrandera Fisheries Center | McCarthy B.J.,La Trobe University
Canadian Journal of Fisheries and Aquatic Sciences | Year: 2014

To restore lateral connectivity in highly regulated river-floodplain systems, it has become necessary to implement localized, "managed" connection flows, made possible using floodplain irrigation infrastructure. These managed flows contrast with "natural", large-scale, overbank flood pulses. We compared the effects of a managed and a natural connection event on (i) the composition of the large-bodied fish community and (ii) the structure of an endangered catfish population of a large floodplain lake. The change in community composition following the managed connection was not greater than that exhibited between seasons or years during disconnection. By contrast, the change in fish community structure following the natural connection was much larger than that attributed to background, within-and between-year variability during disconnection. Catfish population structure only changed significantly following the natural flood. While the natural flood increased various population rates of native fishes, it also increased those of non-native carp, a pest species. To have a positive influence on native biodiversity, environmental flows may need to be delivered to floodplains in a way that simulates the properties of natural flood pulses. A challenge, however, will be managing river-floodplain connectivity to benefit native more than non-native species. Source

Baumgartner L.J.,Narrandera Fisheries Center | Daniel Deng Z.,Pacific Northwest National Laboratory | Thorncraft G.,National University of Laos | Boys C.A.,Port Stephens Fisheries Institute | And 3 more authors.
Journal of Renewable and Sustainable Energy | Year: 2014

Tropical rivers have high annual discharges optimal for hydropower and irrigation development. The Mekong River is one of the largest tropical river systems, supporting a unique mega-diverse fish community. Fish are an important commodity in the Mekong, contributing a large proportion of calcium, protein, and essential nutrients to the diet of the local people and providing a critical source of income for rural households. Many of these fish migrate not only upstream and downstream within main-channel habitats but also laterally into highly productive floodplain habitat to both feed and spawn. Most work to date has focused on providing for upstream fish passage, but downstream movement is an equally important process to protect. Expansion of hydropower and irrigation weirs can disrupt downstream migrations and it is important to ensure that passage through regulators or mini hydro systems is not harmful or fatal. Many new infrastructure projects (<6 m head) are proposed for the thousands of tributary streams throughout the Lower Mekong Basin and it is important that designs incorporate the best available science to protect downstream migrants. Recent advances in technology have provided new techniques which could be applied to Mekong fish species to obtain design criteria that can facilitate safe downstream passage. Obtaining and applying this knowledge to new infrastructure projects is essential in order to produce outcomes that are more favorable to local ecosystems and fisheries. © 2014 AIP Publishing LLC. Source

Cameron L.M.,Grafton Fisheries Center | Cameron L.M.,Southern Cross University of Australia | Baumgartner L.J.,Narrandera Fisheries Center | Bucher D.J.,Southern Cross University of Australia | Robinson W.,Charles Sturt University
Fisheries Management and Ecology | Year: 2012

Fishes are often stocked outside natural distribution ranges with inadequate information on target streams, particularly thermal regimes. Australian bass, Macquaria novemaculeata (Steindachner), is a catadromous species that is regularly stocked into upland reaches of rivers and impoundments in south-eastern Australia. Critical Thermal Minima (CTMin) were determined for age-0 Australian bass fingerlings with a mean fork length of 64.4±0.4mm and weighing 3.8±0.8g. Four treatments were used, including three replicate aquaria for each treatment. Fingerlings were acclimated at either 8 or 15°C at densities of 15 fish in 56-L glass aquaria. Water temperatures were then decreased at either 1°Cday -1 or 1°Ch -1 until loss of equilibrium (LOE), which occurred between 3 and 7°C. Mean CTMin among treatments was 3.22-4.64°C and was influenced by acclimation temperature and rate of temperature decline. Fingerlings acclimated at 8°C subjected to a temperature decline of 1°Ch -1 experienced highest LOE temperature. Post-LOE mortality among treatments was highest at 100% in the 8°C acclimation with a 1°Cday -1 temperature decline. Mortalities following LOE occurred within 5days. The results suggest that stocking age-0 Australian bass is unlikely to be successful in areas where winter temperatures fall below 6°C. © 2012 Blackwell Publishing Ltd. Source

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