Goulburn River Research Articles

Goulburn River experimental catchment data set

This paper describes the data set from the 6540‐km2 Goulburn River experimental catchment in New South Wales, Australia. Data have been archived from this experimental catchment since its inception in September 2002. Land use in the northern half of the catchment is predominantly cropping and grazing on basalt‐derived soils, with the south being cattle and sheep grazing on sandstone‐derived soils; only the floodplains are cleared of trees in the south. Monitoring sites are mainly concentrated in the nested Merriwa (651 km2) and Krui (562 km2) subcatchments in the northern half of this experimental catchment with a few monitoring sites located in the south. The data set comprises soil temperature and moisture profile measurements from 26 locations; meteorological data from two automated weather stations (data from a further three stations are available from other sources) including precipitation, atmospheric pressure, air temperature and relative humidity, wind speed and direction, soil heat flux, and up‐ and down‐welling short‐ and long‐wave radiation; streamflow observations at five nested locations (data from a further three locations are available from other sources); a total of three surface soil moisture maps across a 40 km × 50 km region in the north from ∼200 measurement locations during intensive field campaigns; and a high‐resolution digital elevation model (DEM) of a 175‐ha microcatchment in the Krui catchment. These data are available on the World Wide Web at http://www.sasmas.unimelb.edu.au.

The late-Holocene origin of the modern Murray River course, southeastern Australia

The modern course of the Murray River flows south around the Cadell Tilt Block in southeastern Australia. The avulsion that took the river in this direction formed the Barmah Choke, a reach with an unusually straight planform. This morphology has been used to argue Holocene inertia of the modern river system. The avulsion was initially placed at ∼ 10 ka on the basis of a single charcoal age. Optically stimulated luminescence (OSL) and AMS 14C dating of deposits along the Barmah Choke demonstrates that the Murray has not been inert during this period. A digitate delta deposited on the floor of a palaeolake by the avulsion is only ∼ 550 years old. Point bar deposition along the Choke also began around this time. The Murray River probably followed the course of Bullatale Creek for most of the Holocene. It formed large, inset meander scrolls of Pleistocene ‘Kotupna-type’ along this creek course but without source-bordering dunes. The persistence of Kotupna-type bedload along this course suggests that there was no simple switch to suspended load channels at the Pleistocene/Holocene transition. The Barmah Choke avulsion trebled the discharge of the Goulburn River causing morphological adjustment and formation of new reaches downstream. The extensive Barmah and Gunbower-Koondrook red gum forests probably arose from the increased flood flows. Pollen and spores from lacustrine sediments beneath the Choke show that the vegetation ∼ 4000 years ago was very different. The lake and hinterland began to dry from this time and the lake became a swamp. A pedogenic interval shows that the swamp was dry for lengthy periods prior to deposition of the digitate delta.

Uranium-series isotopes in colloids and suspended sediments: Timescale for sediment production and transport in the Murray–Darling River system

We have measured 238U– 234U– 230Th radioactive disequilibria in five size fractions of colloids and suspended sediments for four rivers from the Murray–Darling River basin (SE Australia). Continuous compositional trends of composition are observed for ( 234U/ 238U) and ( 230Th/ 238U) activity ratios over the range of size fractions studied. They are explained by the variable contribution of two components: detrital alumino-silicates and organic matter. Using relationships between activity ratios and the loss-on-ignition, it is possible to estimate the U-series isotopic composition of both detrital and organic end-members, which provide the best estimate for the composition of the true detrital phase (i.e. controlled only by the removal of elements through weathering) and the true dissolved phase (i.e. colloid-free), respectively. When performing a single filtration at 0.2 μm, it appears that size fractions > and < 0.2 μm underestimate the disequilibrium in both the true detrital and dissolved phases, respectively. We show that erosion does not currently operate in steady state in the Murray–Darling basin and catchment soils are currently being degraded. This could be a consequence of the intensification of agriculture and deforestation over the past 100 yr. The residence time of sediments in the different sub-basins is calculated by computing the composition of the detrital phase with a continuous weathering model. It yields 11 ± 2 kyr for the Darling River basin, only 2–3 ± 1 kyr for the Murray River and 7 ± 2 kyr for the Goulburn River. These values are correlated with the age of changes in river dynamics, in turn probably controlled by climate fluctuation, and indicate the age of the modern river system for each sub-basin.

Temporal change in fish assemblages in the lower Goulburn River, south-eastern Australia: comment on Pollino et al. (2004)

A recent analysis of fish assemblages in the Goulburn River, south-eastern Australia, used fish survey data collected between 1970 and 2002 to examine spatial patterns in the compositions and relative abundances of fish assemblages in the catchment. Based on this analysis, it was concluded that the native fish fauna of the Goulburn River is in a stressed condition and that introduced species dominate the fish assemblages. Fish survey data collected in 1982–1983 are compared with data collected in 2003–2004 to examine whether fish assemblages in the lower Goulburn River were stable at the temporal scale at which the data were aggregated in the previous analysis. The results show significant differences in fish assemblage composition between the two surveys, suggesting that fish assemblage structure in the lower Goulburn River did not remain stable between 1982–1983 and 2003–2004. The aggregation of data collected over several decades has the potential to confound analysis of spatial variations in fish assemblages and is unlikely to provide a reliable means of assessing their current condition.

Reply to the comment by Crook and Koster (2006) 'Temporal change in fish assemblages in the lower Goulburn River, south-eastern Australia'

In an earlier paper, multivariate statistics were used on historic fisheries data sets to show spatial differences between fish communities in the Goulburn Catchment (Victoria, Australia). In this reply paper, some further statistical analyses are presented to provide evidence for the assertion that fish communities at each site were stable over the temporal scale of the data was valid. Indeed, evidence for the stabilisation and persistence of fish communities after a major disturbance has also been recognised in other studies. Furthermore, in making judgements about the stability and persistence of fish communities, the scale of a study is an important factor, with patterns at the catchment scale often not being the same as those at smaller spatial scales.

Quantifying uncertainty in environmental flow assessments

Environmental flow proposals are normally justified by predictions of geomorphological and ecological responses. Uncertainty in these predictions is widely acknowledged but rarely quantified. This paper uses a Monte Carlo analysis to quantify the effects of multiple sources of uncertainty on the environmental flow required to flush fine sediments from a gravel bed reach of the Goulburn River, Victoria. Sources of uncertainty are associated with sampling, measurement and selection of model parameters. The volume of water required to mimic the natural sediment flushing regime is estimated to be 160 Gl/year. The uncertainty analysis provides a 90% confidence interval for this volume of 10 Gl/year to 360 Gl/year. The greatest source of uncertainty in this case is estimation of flow resistance (or Manning n) for the study reach. The study highlights the need for coordinating data collection and modelling when choosing environmental flows for rivers.

Electrical Methods for Detection and Discrimination of Saline Groundwater in Clay-Rich Sediments in Northern Victoria

Conductivity surveys (Induced Polarization and Transient Electromagnetics) have been conducted on the southern bank of the Goulburn River, near Murchison, Victoria, to discriminate between clay zones and saline discharge streams. The combined surveys provide a consistent dataset and multiple conductive zones are delineated within the regolith. The ambiguity between salinity and clay content variations is resolved by means of the induced polarization parameters. In particular, normalised chargeability values are shown to highlight the location of clay lenses containing saline pore water.

Fish communities and habitat changes in the highly modified Goulburn Catchment, Victoria, Australia

Evidence for the decline in native fish communities in the lowland Goulburn Catchment has been based primarily on studies investigating changes to environmental conditions as a result of river regulation. The present study aggregates historical fisheries data to spatially compare native fish communities in different parts of the catchment. Multivariate analyses demonstrate that distinctly different community compositions are found in different parts of the catchment. Eildon Dam, a deep release reservoir, has drastically altered the hydrology and water quality of the upper Goulburn River, and ordination analyses show that this has created both physical and artificial barriers to movement of native fish into the main channel. Concurrently, fisheries data from the upper main channel show the community is highly divergent compared to the remaining catchment. Further downstream, Goulburn Weir creates a barrier to fish movement between Lake Nagambie and the lower Goulburn Catchment, and alters the natural hydrological regime. Similarity Percentage analyses demonstrate that these stressors have facilitated the establishment of alien species, which dominate fish abundance in the upper and lower main channels. The current study emphasises the need to explore alternatives for improving management strategies to rehabilitate fish communities throughout the Goulburn Catchment.

The effects of bushfires on hydrological processes using a paired-catchment analysis

Several problems associated with capturing the effects of bushfires on hydrological processes in the Goulburn River catchment (6810 km2), Hunter Valley, Australia are investigated using a paired-catchment analysis. It is suggested, first, that the within-year-missing data, as defined in this paper, need to be examined carefully when using the double-mass curve of annual total discharge in a paired-catchment analysis. Second, in order to provide an accurate precipitation background, which is one of the most important prerequisites for a paired-catchment analysis, the use of annual average precipitation is strongly recommended together with annual total precipitation when there are large amounts of within-year-missing data. Third, caution is needed in comparing multi-year average precipitation and streamflow data before and after the fire when the data series is not statistically long enough, since the average values for precipitation and streamflow over a different number of years may produce completely contrasting results. Fourth, the analysis of the flow duration curve, which is another useful technique in paired-catchment analysis, needs to be interpreted from the precipitation duration curve. This is because the change of flow duration curve can be caused either from the change of precipitation or the fire. Fifth, the change in streamflow, calculated by subtracting the average streamflow for the non-fire years from the observed streamflow for the years in which fires occurred, is not an efficient way of capturing the fire effects. The problem associated with this approach is not just that the streamflow is strongly dependent on rainfall, as reported elsewhere, but also, it can lead to misinterpretation using the hydrograph when the average streamflow in non-fire years is close to the average streamflow in fire years.

Assessing Long-Term pH Change in an Australian River Catchment Using Monitoring and Palaeolimnological Data

Reviews of stream monitoring data suggest that there has been significant acidification (>1.0 pH unit at some sites) of Victorian streamwaters over the past 3 decades. To assess whether these declines are within the range of natural variability, we developed a diatom model for inferring past pH and applied it to a ca. 3500-yr diatom record from a flood plain lake, Callemondah 1 Billabong, on the Goulburn River, which has among the most substantial observed pH declines. The model has a jackkniffed r2 between diatom inferred and measured pH of 0.77 and a root mean square error of prediction of 0.35 pH units. In the pre-European period, pH was stable (range 6.5-6.7) for approximately 3000 yr. Since European settlement around 160 yr ago, diatom-inferred billabong pH has increased significantly by >0.5 units. We hypothesize that this increase in pH is related to processes associated with land clearance (e.g., increased base cation load and decreased organic acid load). There is no evidence of the recent monitored declines in the Callemondah record, which may indicate that that flood plain lakes and the main stream are experiencing divergent pH trends or that the temporal resolution in the billabong sediment record is insufficient to register recent declines.

Ecological risk to aquatic systems from salinity increases

Salinity is a major problem in many regions of Australia, and is predicted to get considerably worse over the next 30–50 years. Most effort has focused on the terrestrial environment, and specifically on the loss of productive agricultural land. Increased salinity can also result in unwanted changes to aquatic ecosystems in rivers, streams and particularly wetlands.This paper first reviews the importance of assessing risks from salinity increases in a catchment context, and then introduces a disturbance–response conceptual model to assist with the understanding of such situations. Two factors are shown to be particularly important in assessing which freshwater systems will be most susceptible to increases in salinity—the location of the systems in the landscape, and the current ecological condition of the system. The resilience of an ecosystem to salinity disturbances is shown to be a useful concept which with further knowledge may be incorporated into risk-assessment approaches.The development of a new ecological risk assessment approach for assessing risks to aquatic systems in the Goulburn–Broken catchment from increases in salinity over the medium (20 years) and long (100 years) term is reported. The risks to the biota in Hughes Creek, a tributary of the Goulburn River, are assessed by using a probabilistic approach. Current salinity levels in the creek present a low risk to the biota.Finally, the paper addresses the challenge of making the ecological risk assessment method more quantitative by discussing the following two key aspects: how to better quantify the linkages between the key stressors and the biotic components, and how to better handle uncertainties.

Rhetoric and reality in the allocation of water to the environment: a case study of the Goulburn River, Victoria, Australia

AbstractIn the Goulburn River, located in Victoria (Australia), dams and diversions for irrigation have modified streamflows and water temperature, and contributed to environmental degradation that includes declining native fish populations.With the passage of a new Water Act in 1989, the Victorian Government proposed to address environmental and water allocation issues through the development of tradeable water entitlements. Initially, these had a strong environmental focus and were to be allocated within an adaptive management framework that involved monitoring and evaluation to refine the total allowable diversion to sustainable levels. The actual specification of tradeable water entitlements for the Goulburn River, undertaken in 1995, differed substantially from those early proposals. Entitlements were largely based on historical use with limited and ineffective allocation of water to the environment because water temperature was not considered. A water market has been established but market failure is likely to result in an under‐allocation of water to the environment. Access to the market is restricted except to irrigation authorities and water users, and transaction costs and uncertainties in environmental requirements reinforce the status quo in water allocation which is dominated by production values. Copyright © 2002 John Wiley &amp; Sons, Ltd.

Sediment dates with implications for the age of the conversion from palaeochannel to modern fluvial activity on the Murray River and tributaries

Dates for sediment deposition have been obtained for a number of abandoned channels with modern features on the Upper Murray, Kiewa, Ovens and Goulburn Rivers, and from palaeochannel deposits on the Upper Murray River just west of Albury. The dates from modern channels on the Upper Murray are problematic, but suggest modern fluvial activity had begun by 5–9 ka. Two dates from the Ovens and Kiewa Rivers are in agreement with this. West of Albury, a palaeochannel point bar returned an age of 7.4−11.6 ka, and a source bordering sand dune ∼22.5 ka. Sand beneath the floodplain near Albury was aged 7.3 ka, and was not deposited at the same time as underlying gravels, where two embedded trees returned ages of 12 ka. It therefore cannot be established if the sand deposit was associated with either modern or palaeochannel activity. Therefore, on the Upper Murray River the transition from palaeochannel to modern fluvial activity most likely occurred between 7 and 10 ka. In contrast, two dates from an abandoned channel on the Goulburn River indicates that modern channels were active on this river before 11–13 ka. This suggests that palaeochannels were active later on the Upper Murray than on the Goulburn River, and compared with previous work, possibly later than on the Murrumbidgee River and the middle Murray River near Echuca. As upper catchment areas were revegetated following the LGM, discharge or sediment supply may have declined first in lower altitude catchments, like the Goulburn, and last in the high-altitude Upper Murray catchment, creating an asynchronous transition from palaeochannel to modern fluvial activity in subcatchments of the southeast Murray drainage basin.

Effects of phosphorus and nitrogen on growth of pasture plants and VAM fungi in SE Australian soils with contrasting fertiliser histories (conventional and biodynamic)

The soil biological community has been reported to differ between conventional and alternative (organic and biodynamic) farming systems. However, few studies have investigated whether this results in substantial differences in the biological pathways controlling major ecosystem processes, such as plant nutrient uptake. This paper describes a glasshouse experiment conducted using a red-brown earth (Natrixeralf) soil sampled from three conventional and three biodynamic irrigated dairy pastures located in the Goulburn River Valley, Victoria, Australia. The biodynamic soils had not had organic or inorganic fertilisers applied for, on average, 17 years, while the conventional soils had received regular inputs of fertilisers containing soluble phosphorus (P) and nitrogen (N). The experiment examined whether the contrasting fertiliser histories had resulted in different pathways of plant nutrient uptake through assessing the response of white clover ( Trifolium repens L.), perennial rye grass ( Lolium perenne L.) and the indigenous vesicular-arbuscular mycorrhizal (VAM) fungi to addition of four levels of soluble P and N. The response to added P and N did not differ between the conventional and biodynamic soils, although, plants in the biodynamic soils had a slower growth rate and a higher level of colonisation by VAM fungi due to lower initial soil P and N concentrations. Overall, there was no indication that the biodynamic and conventional soils had developed substantially different processes to enhance plant nutrient uptake or that the indigenous VAM fungi differed in their tolerance to applications of soluble nutrients.

Effects of wetting and drying on methane emissions from ephemeral floodplain wetlands in south-eastern Australia

Four approaches were used to assess the effect ofinundation on methane emissions from floodplainwetlands in Victoria, Australia: (i) fieldobservations following natural rainfall events; (ii)experimental manipulation of water levels in smallfloodplain depressions; (iii) experimentalmanipulation of water levels in replicated mesocosms;and (iv) in vitro incubation of floodplainsediment under laboratory conditions. Raftery'sSwamp, a large (150 ha) wetland on the floodplain ofthe Goulburn River, became inundated in June 1993following autumn-winter rainfall. Methane emissionspeaked (1.7 ± 0.05 mmol m-2 h-1) somesix months later, and the methane content of sedimentgas bubbles reached 59% v/v, even though the positivesediment redox potentials (176 to 243 mV) indicatedthat sediments were only moderately reducing. Threesmall (< 1 ha) depressions on the floodplains of theRiver Murray and Kiewa River were inundated eithernaturally (by rain and/or overflow from nearby rivers)or artificially by flooding at specific times of year;emissions from these sites were usually negligibleafter flooding in autumn or winter. In contrast, theonset of methane emission was very rapid (within 3 to6 days) after the depressions had been flooded insummer, and the methane content of sediment gasbubbles could then reach 36% v/v. At their peak,emissions from the ephemeral wetlands were similar topeak emissions from permanent wetlands insouth-eastern Australia. Emissions from replicatedwetland mesocosms (4.5 m diameter, 0.9 m deep) werealways very small (<0.2 mmol m-2 h-1),regardless of time of flooding, water depths, orseason. In vitro incubation of wetland sedimentunder anaerobic conditions indicated a progressivedecrease in benthic methanogenesis with sedimentdesiccation and exposure to air. Ephemerallyinundated floodplain wetlands may be sites ofsignificant methane emission, especially over thesummer months. Moreover, the survival and rapidreactivation of methanogenic archaea after prolongeddrying of wetland sediments suggests thatmethanogenesis is possible even from re-wettedfloodplain environments that had earlier experiencedan extended dry phase.

Seasonal-Variation in the Ranging Behavior of the Platypus (Ornithorhynchus-Anatinus) on the Goulburn River, Victoria

Radio-telemetry was used to study the effects of changing reproductive condition and water levels on the ranging behaviour and activity patterns of adult male platypuses in the Goulburn River, Victoria. Home-range size varied greatly between individuals, from 2 . 45 to 15 . 45 ha, but differences in the body weight of individuals did not account for this variability. There was no correlation between the number of burrows used by males and their body size or home-range length. Changing river levels or the animal's breeding condition did not appear to affect the duration of activity periods, which remained constant throughout the study. All radio-tracked animals foraged in a submerged backwater area during high-water conditions, suggesting that platypuses are opportunistic in their habitat usage and may avoid fast-flowing water if calmer areas are available. Although the home ranges of adult males overlapped extensively during the non-breeding period, there was evidence of spatial separation during the breeding season, when animals occupied separate core areas. In addition there appeared to be some temporal separation between adult males during the breeding season. During this period there was greater variation in the times at which animals emerged from their burrows, and some animals became diurnal.

Thermoluminescence chronology of late quaternary deposition on the riverine plain of South‐Eastern Australia

SUMMARY Thermoluminescence (TL) dating of surficial deposits of the Riverine Plain of south‐eastern Australia has revealed a record of fluvial, aeolian and lacustrine deposition during the last 100,000 years (100Ka). At the end of the last interglacial the Plain was networked by low sinuosity, bedload‐dominated prior streams which declined in activity after about 85Ka. A subsequent phase of prior stream activity in the northern Murrumbidgee region dates at between 50 and 40Ka and corresponds with a period of high lake levels in southern Australia. Local tectonism on the southern part of the plain confuses an interpretation of riverine response to changing Pleistocene climate. TL dates show that drainage diversion in response to tectonic movement along the Cadell Fault near Echuca began as early as 60Ka but that the damming of the Goulburn River to produce Lake Kanyapella did not occur until about 30Ka. Hydrologic changes on the Riverine Plain correlate broadly with those documented elsewhere in Australia, notably in the Lake Eyre Basin and numerous inland playa systems.

Effects of carp, Cyprinus carpio L., on communities of aquatic vegetation and turbidity of waterbodies in the lower Goulburn River basin

Densities of carp, ranges of turbidity, and details of communities of aquatic vegetation from 1979 to 1982 are given for several waterbodies in the Goulburn River valley including the Broken River, near Shepparton, Victoria. The turbidity values at all sites were high, typical of Australian inland waterbodies. There was no association between high carp densities and high turbidity, and populations of carp did not appear to increase turbidity. Observed turbidity increases at each site appeared to be related to hydrological changes. Fluctuation of water levels was also an important factor determining the extent of aquatic vegetation communities. However, circumstantial evidence is presented that shallow-rooted and soft-leaved aquatic vegetation such as Potamogeton spp. have been reduced by carp.

Stochasticity in Stream Fish Communities: An Alternative Interpretation

Stochasticity in Stream Fish Communities: An Alternative Interpretation

Distribution of native and introduced fish in the Seven Creeks River system, Victoria

The distribution offish within the Seven Creeks River system, a tributary of the Goulburn River in the Murray–Darling basin, was determined primarily by a survey carried out during the summer of 1975–76. Information on the past occurrence of fish in the system was obtained from historical records. Seventeen species offish, eleven native and six exotic, have been recorded from the system. Habitat characteristics, cohabiting species and food habits are presented for each species recorded during the survey, and factors affecting present distributions are discussed. Siltation appears to have had adverse effects on native Murray cod, Maccullochella peeli, and Macquarie perch, Macquaria australasica, both of which were once common in the lower reaches of the system. The presence of Macquarie perch and the rare native trout cod, Maccullochella macquariensis, in the upper reaches of the system is traced to fish released in 1921 and 1922. A nother native species, the western carp gudgeon, Hypseleotris klunzingeri, was first observed in the system only after it had been introduced into farm dams in the area in the mid 1960s. Relationships between native and introduced fish are complex. Although the food requirements of some native and introduced species overlap and some native fish have been found in the stomachs of introduced species, the only evidence of a substantial effect of an introduced species on a native species is the apparent fragmentation of the range of common mountain galaxiids, Galaxias olidus, by brown trout, Salmo trutta, whose numbers in the system were, until recently, augmented by continual releases of hatchery-reared fish.