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.
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.
Cameron L.,Grafton Fisheries Center |
Baumgartner L.,Narrandera Fisheries Center |
Butler G.,Grafton Fisheries Center |
Bucher D.,Southern Cross University of Australia |
Lou D.-C.,James Cook University
Fisheries Research | Year: 2016
Understanding the contribution of stocking to fish populations is an essential part of any program to increase fish numbers and abundance. However, subsequent assessments that aim to quantify the success of fish stocking are rarely considered. Juvenile-sized (<200 mm) Australian bass (Percalates novemaculeata), from the upper Snowy River, southern New South Wales (NSW), Australia (assumed to be stocked), wild mature-sized (>400 mm) fish from estuarine areas of the Snowy River, juveniles (15-30 mm) from a commercial Australian bass hatchery facility known to have supplied fish for past stockings in the Snowy River, and wild fish (>400 mm) considered as controls from the Clarence River in northern NSW were used for otolith microchemical analysis. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used to measure Sr:Ca and Ba:Ca ratios at the otolith core and across radial transects to verify natal origins of fish and more specifically, to confirm the origin of fish caught in the river that were assumed to have originated from a recent stocking program. Otolith core Sr:Ca ratios of juvenile fish collected from the upper Snowy River and hatchery fish were not significantly different suggesting they originated from the same source. Significant differences were found in core Sr:Ca and Ba:Ca between known origin hatchery fish and wild fish. Significantly higher Sr:Ca ratios were found at otolith cores compared to the edges in fish collected from the upper Snowy River, suggesting early life was spent in more saline conditions prior to stocking compared to wild fish. Otolith transect data showed a consistent decrease in Sr:Ca ratios and a simultaneous increase in Ba:Ca ratios at approximately 17-59 mm from the core, corresponding with the size at which these fish were stocked. This study has demonstrated that otolith microchemistry can successfully distinguish stocked fish from wild recruits and reveals the timing of natural migrations or artificial translocations. © 2016 Elsevier B.V.
Boys C.A.,Port Stephens Fisheries Institute |
Robinson W.,Narrandera Fisheries Center |
Robinson W.,Charles Sturt University |
Baumgartner L.J.,Narrandera Fisheries Center |
And 2 more authors.
PLoS ONE | Year: 2013
Fish screens can help prevent the entrainment or injury of fish at irrigation diversions, but only when designed appropriately. Design criteria cannot simply be transferred between sites or pump systems and need to be developed using an evidence-based approach with the needs of local species in mind. Laboratory testing is typically used to quantify fish responses at intake screens, but often limits the number of species that can studied and creates artificial conditions not directly applicable to screens in the wild. In this study a field-based approach was used to assess the appropriateness of different screen design attributes for the protection of a lowland river fish assemblage at an experimental irrigation pump. Direct netting of entrained fish was used along with sonar technology to quantify the probability of screen contact for a Murray-Darling Basin (Australia) fish species. Two approach velocities (0.1 and 0.5 m.sec-1) and different sizes of woven mesh (5, 10 and 20 mm) were evaluated. Smaller fish (<150 mm) in the assemblage were significantly more susceptible to entrainment and screen contact, especially at higher approach velocities. Mesh size appeared to have little impact on screen contact and entrainment, suggesting that approach velocity rather than mesh size is likely to be the primary consideration when developing screens. Until the effects of screen contacts on injury and survival of these species are better understood, it is recommended that approach velocities not exceed 0.1 m.sec-1 when the desire is to protect the largest range of species and size classes for lowland river fish assemblages in the Murray-Darling Basin. The field method tested proved to be a useful approach that could compliment laboratory studies to refine fish screen design and facilitate field validation. © 2013 Boys et al.
Rourke M.L.,Monash University |
Rourke M.L.,Australian Department of Primary Industries and Fisheries |
Rourke M.L.,Narrandera Fisheries Center |
McPartlan H.C.,Australian Department of Primary Industries and Fisheries |
And 3 more authors.
Marine and Freshwater Research | Year: 2010
Stocking wild fish populations with hatchery-bred fish has numerous genetic implications for fish species worldwide. In the present study, 16 microsatellite loci were used to determine the genetic effects of nearly three decades of Murray cod (Maccullochella peelii peelii) stocking in five river catchments in southern Australia. Genetic parameters taken from scale samples collected from 1949 to 1954 before the commencement of stocking were compared with samples collected 16 to 28 years after stocking commenced, and with samples from a local hatchery that supplements these catchments. Given that the five catchments are highly connected and adult Murray cod undertake moderate migrations, we predicted that there would be minimal population structuring of historical samples, whereas contemporary samples may have diverged slightly and lost genetic diversity as a result of stocking. A Bayesian Structure analysis indicated genetic homogeneity among the catchments both pre-and post-stocking, indicating that stocking has not measurably impacted genetic structure, although allele frequencies in one catchment changed slightly over this period. Current genetic diversity was moderately high (H E≤0.693) and had not changed over the period of stocking. Broodfish had a similar level of genetic diversity to the wild populations, and effective population size had not changed substantially between the two time periods. Our results may bode well for stocking programs of species that are undertaken without knowledge of natural genetic structure, when river connectivity is high, fish are moderately migratory and broodfish are sourced locally. © CSIRO 2010.
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.
Patra R.W.,Office of Environment and Heritage |
Patra R.W.,University of Technology, Sydney |
Patra R.W.,Narrandera Fisheries Center |
Chapman J.C.,Office of Environment and Heritage |
And 6 more authors.
Environmental Toxicology and Chemistry | Year: 2015
Warming of freshwaters as a result of climate change is expected to have complex interactions with the toxicity of contaminants to aquatic organisms. The present study evaluated the effects of temperature on the acute toxicity of endosulfan, chlorpyrifos, and phenol to 3 warm water species of fish-silver perch, rainbowfish, and western carp gudgeon-and 1 cold water species, rainbow trout. Endosulfan was more toxic to silver perch at 30°C and 35°C than at 15°C, 20°C and 25°C during short exposures of 24h, but at 96h, temperature had no effect on toxicity. Toxicity to rainbow trout increased with increasing temperature, whereas warm water species exhibited maximum toxicity at around 30°C, decreasing again toward 35°C. Chlorpyrifos became more toxic to all species with increasing temperature. Phenol toxicity to all species decreased at low to intermediate temperatures; but as temperatures increased further toward the upper thermal limit, phenol became more toxic. Increasing toxicity in the upper thermal range of cold water species may contribute to upstream range contraction in rivers with high toxicant loads. In contrast, warm water species may not exhibit a range shift within rivers as a result of interactions between temperature and toxicity. Catchment management to offset global warming at local scales may present opportunities to mitigate increased toxicity of contaminants to fish. © 2015 SETAC.
Baumgartner L.J.,Narrandera Fisheries Center |
Boys C.A.,Port Stephens Fisheries Center |
Stuart I.G.,Arthur Rylah Institute for Environmental Research |
Zampatti B.P.,SARDI Aquatic Sciences Center
Australian Journal of Zoology | Year: 2010
To provide passage for migratory native fish, a series of 14 vertical-slot and lock fishways are being constructed on the Murray River in south-eastern Australia. Three of these vertical-slot fishways, at Locks 7, 9 and 10, have a conservative slope (1V:32H) and are designed with internal hydraulics suitable for the passage of a broad size range of fish (30-1000 mm long). An assessment of these fishways was performed using a combined trapping survey and passive integrated transponder (PIT) approach to determine fishway effectiveness at passing an entire fish community. Fish were trapped within the three fishways between 2004 and 2006, where a total of 13626 individuals comprising 13 species were collected from 48 sample days (24h each). Trapping data revealed that the three fishways successfully passed fish within the target size range, though significantly greater numbers of individuals smaller (10-29mm long) than the target size range could not ascend. PIT tagging revealed important information on fishway ascent times, descent times, seasonality and diel behaviour of medium and large fish. Although each method alone had advantages and disadvantages, the dual assessment approach was useful as it permitted an assessment of fishway success and also provided insights into migratory fish behaviour. © CSIRO 2010.
PubMed | University of Technology, Sydney, Narrandera Fisheries Center and Office of Environment & Heritage
Type: Journal Article | Journal: Environmental toxicology and chemistry | Year: 2015
Warming of freshwaters as a result of climate change is expected to have complex interactions with the toxicity of contaminants to aquatic organisms. The present study evaluated the effects of temperature on the acute toxicity of endosulfan, chlorpyrifos, and phenol to 3 warm water species of fish-silver perch, rainbowfish, and western carp gudgeon-and 1 cold water species, rainbow trout. Endosulfan was more toxic to silver perch at 30C and 35C than at 15C, 20C and 25C during short exposures of 24h, but at 96h, temperature had no effect on toxicity. Toxicity to rainbow trout increased with increasing temperature, whereas warm water species exhibited maximum toxicity at around 30C, decreasing again toward 35C. Chlorpyrifos became more toxic to all species with increasing temperature. Phenol toxicity to all species decreased at low to intermediate temperatures; but as temperatures increased further toward the upper thermal limit, phenol became more toxic. Increasing toxicity in the upper thermal range of cold water species may contribute to upstream range contraction in rivers with high toxicant loads. In contrast, warm water species may not exhibit a range shift within rivers as a result of interactions between temperature and toxicity. Catchment management to offset global warming at local scales may present opportunities to mitigate increased toxicity of contaminants to fish.
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.