Kefford B.J.,RMIT University |
Kefford B.J.,University of Technology, Sydney |
Schafer R.B.,RMIT University |
Liess M.,Helmholtz Center for Environmental Research |
And 3 more authors.
Environmental Toxicology and Chemistry | Year: 2010
A new method is presented to determine retrospectively proportional changes of species composition in a community at risk from particular concentrations of chemical stressors. The method makes estimates with some similarities to those claimed by species sensitivity distributions (SSDs) but is based on species presence/absence field data and requires assumptions that are more likely to be met. The method uses Jaccard's index (JI), the proportion of species in common to two samples. At a similar level of contamination, the occurrence of species is usually highly variable, and thus JI values between individual pairs of samples can be low. However, by pooling samples with a similar contamination level, an increasingly complete set of species present at this level of contamination is gained. Our method involves calculating JI between randomly selected groups of samples (pooled sample sets) with similar and different levels of contamination. It then relates changes in JI to the difference in contamination and produces estimates of the proportional change in species between preselected categories of contamination. The application of the method is illustrated by using data on riverine freshwater macroinvertebrates exposed to salinity in southeastern Australia; pesticide runoff potential in the Aller River Catchment, Germany; and metal pollution (principle Cu) in the Clark Fork River Catchment, Montana, USA. © 2010 SETAC.
Gibson R.,Environment Protection Authority |
Gibson R.,University of New England of Australia |
Conn B.J.,National Herbarium of New South Wales |
Bruhl J.J.,University of New England of Australia
Australian Systematic Botany | Year: 2012
A phenetic study of morphological characters of the Drosera peltata complex (Droseraceae) supports the recognition of the following taxa: D. peltata from wetlands of south-eastern Australia; D. auriculata from south-eastern Australia and New Zealand; the morphologically variable D. hookeri from south-eastern Australia and northern New Zealand; the widespread D. lunata from southern and South-East Asia, as well as northern and north-eastern Australia; and the new species D. yilgarnensis R.P.Gibson B.J.Conn is here described, from around granite outcrops of south-western Australia. D. bicolor from south-western Australia is recognised as a distinct species outside of the D. peltata complex. D. insolita, considered until recently as a distinct species, is reduced to synonymy of D. lunata. Phenotypic plasticity, vegetative similarity and fleetingly produced diagnostic floral and seed characters within the complex pose significant challenges in understanding the taxonomy of these taxa. © 2012 CSIRO.
Bogoda K.,Environment Protection Authority |
Bouazza A.,Monash University
10th International Conference on Geosynthetics, ICG 2014 | Year: 2014
The geomembrane component of a composite liner is essentially impervious to liquid flow when devoid of holes or defects. However, defects in the geomembrane can occur even with carefully controlled manufacture and damages can be found even in sites where a strict construction quality assurance program has been put in place. This paper reports on a case study regarding a landfill cell located in Melbourne where an electrical survey was conducted to verify the quality of the installation process of the geomembrane across the cell floor. The electrical survey indicated the presence of 57 holes and about 350 dimples in the high density polyethylene (HDPE) geomembrane. The causation and the remediation of these defects are discussed in detail in this paper.
Examining the ecological consequences of restoring flow intermittency to artificially perennial lowland streams: Patterns and predictions from the broken-boosey creek system in Northern Victoria, Australia
Reich P.,Monash University |
McMaster D.,Monash University |
Bond N.,Monash University |
Metzeling L.,Environment Protection Authority |
Lake P.S.,Monash University
River Research and Applications | Year: 2010
The reinstatement of natural flow regimes is a rapidly emerging issue in river restoration worldwide. In northern Victoria, Australia, efforts are presently underway to restore a natural, intermittent flow regime to several streams which have received perennial diversions for both irrigation and stock and domestic water-supplies for over 100 years. A pipeline to deliver water to landholders will significantly reduce transmission losses throughout the system allowing irrigation canals and diversion weirs to be decommissioned. The motivation for flow alteration in this system lies primarily in reducing inefficiencies in water delivery which, in turn, will be used to meet escalating demands on water resources. The ecological impact of the flow regime shift on these streams is likely to be substantial. This study utilized an existing artificial hydrological gradient (from perennial to intermittent) in two creek systems, to explore relationships between flow regime and a range of ecological variables. These data provide a benchmark against which to assess ecological changes once flow has been altered and form the basis for predicting changes that can assist future management decisions. Data collected from 10 sites across a strong hydrological gradient detected clear differences in geomorphology, water quality and biotic assemblages (macrophytes, macroinvertebrates and fish). By examining the relationship between flow regime and the distribution of biota we identify both the positive and negative outcomes of restoring naturally intermittent flow regimes within artificially perennial lowland streams. The reinstatement of intermittent flow regimes in artificially perennial streams will continue in many parts of the world as water delivery via these systems becomes increasingly uneconomical. While flow restoration may in principle be regarded as a positive step, these findings emphasize the need to consider fully the ecological consequences of restoring historical hydrological regimes to streams within the context of other human induced catchment disturbances. © 2009 John Wiley & Sons, Ltd.
Thomson J.R.,Monash University |
Bond N.R.,Monash University |
Bond N.R.,Griffith University |
Cunningham S.C.,Monash University |
And 4 more authors.
Global Change Biology | Year: 2012
Aquatic biodiversity faces increasing threats from climate change, escalating exploitation of water and land use intensification. Loss of vegetation in catchments (= watersheds) has been identified as a substantial problem for many river basins, and there is an urgent need to better understand how climate change may interact with changes in catchment vegetation to influence the ecological condition of freshwater ecosystems. We used 20 years of biological monitoring data from Victoria, southeastern Australia, to explore the influences of catchment vegetation and climate on stream macroinvertebrate assemblages. Southeastern Australia experienced a severe drought from 1997 to 2009, with reductions of stream flows >50% in some areas. The prolonged drying substantially altered macroinvertebrate assemblages, with reduced prevalence of many flow-dependent taxa and increased prevalence of taxa that are tolerant of low-flow conditions and poor water quality. Stream condition, as assessed by several commonly used macroinvertebrate indices, was consistently better in reaches with extensive native tree cover in upstream catchments. Prolonged drought apparently caused similar absolute declines in macroinvertebrate condition indices regardless of vegetation cover, but streams with intact catchment and riparian vegetation started in better condition and remained so throughout the drought. The largest positive effects of catchment tree cover on both water quality and macroinvertebrate assemblages occurred above a threshold of ca. 60% areal tree cover in upstream catchments and in higher rainfall areas. Riparian tree cover also had positive effects on macroinvertebrate assemblages, especially in warmer catchments. Our results suggest that the benefits of extensive tree cover via improved water quality and in-channel habitat persist during drought and show the potential for vegetation management to reduce negative impacts of climatic extremes for aquatic ecosystems. © 2012 Blackwell Publishing Ltd.
Bond N.,Monash University |
McMaster D.,Environment Protection Authority |
Reich P.,Arthur Rylah Institute for Environmental Research |
Thomson J.R.,Monash University |
Lake P.S.,Monash University
Freshwater Biology | Year: 2010
1. Understanding the relationships between flow regime and the distribution of biota is critical for managing flows in regulated rivers. In northern Victoria, Australia, efforts are presently underway to restore a natural, intermittent flow regime to several streams which, for over 100 years, have received perennial diversions as part of a stock, irrigation and domestic water supply.2. Bayesian, model-averaged, binomial regression was used to predict probabilities of occurrence for 13 fish species, including five non-native species, based on hydrologic variables characterising both the current and modelled future flow regimes at 10 sites representing a range of hydrologic regimes (categorised here as heavily regulated, moderately regulated and unregulated).3. Regression models accurately predicted present probabilities of occurrence for most species across all sites. The models predicted a reduced likelihood of large, native, flow-dependent species occurring at regulated sites following flow restoration. Predictions regarding the future distribution of widespread species including two small-bodied native and four exotic species were less certain as current distributions of these widespread species were unrelated to hydrologic variables we examined and thus unlikely to be significantly affected by flow restoration. The distributions of two small native species currently restricted to unregulated sites are predicted to increase throughout the system.4. This study illustrates the effects of artificially induced perennial flow on lowland fish distributions. Furthermore, the combination of pre-restoration data together with predictive modelling provides valuable insights into the likely outcomes of flow regime shifts.5. This study clearly demonstrates the value of combining empirical research and modelling in guiding environmental flow and ecosystem restoration decisions. Knowledge from the study is now helping guide management decisions and the development of mitigation strategies to protect highly valued species in the system from potential future threats. © 2010 Blackwell Publishing Ltd.
Lee R.S.,Environment Protection Authority |
Black K.P.,University of Melbourne |
Bosserel C.,University of Western Australia |
Greer D.,ASR Pty Ltd
Ocean Dynamics | Year: 2012
Observations of a large temperate embayment in Victoria, Australia, reveal a sustained climatic shift that occurred in response to a prolonged drought in the region during 1997-2009. Historically, the bay is fresher than the ocean with fresh outflow to the sea. However, the drought has caused substantially elevated salinity and temperatures above adjacent oceanic waters. The bay's capacity to dilute and flush waste discharges to the ocean was also changed. Observed conditions have been numerically modelled with hydrodynamic and coupled lagrangian particle dispersion models to test differences in dispersion and exchange during historically fresher conditions and hypersaline bay scenarios. Further scenarios were tested for projected climate conditions which were similar to the recent drought responses in the bay. The models identified the effects on the circulation of the climatic shift including regions of increased vulnerability to extreme salinity in the bay, with some existing discharges concentrating in these regions of heightened vulnerability. Absolute salinity in the bay could reach critical levels of over 38 g kg-1, in places, which may compromise bay ecology. © Springer-Verlag 2012.
Irving A.D.,South Australian Research And Development Institute |
Tanner J.E.,South Australian Research And Development Institute |
Gaylard S.G.,Environment Protection Authority
Marine Pollution Bulletin | Year: 2013
Assessing environmental condition is essential for the management of coasts and their resources, but better management decisions occur when large databases are simplified into more manageable units of information. Here we present the habitat structure index (HSI), which enables rapid assessment and direct comparison of seagrass habitat structure using scores of 0 (poor) to 100 (excellent) based on integrating five habitat variables: area, continuity, proximity, percentage cover, and species identity. Acquiring data to calculate the HSI can be done in situ or from video recordings, and requires relatively simple methodology of belt transects, estimating percentage cover, and basic taxonomy. Spatiotemporal comparisons can usefully identify locations and periods of seagrass habitat change, potentially providing an early warning indicator of habitat damage and decline in environmental quality. Overall, the integrative approach of the HSI represents a step toward simplifying the exchange of environmental information among researchers, coastal managers, and governing bodies. © 2012 Elsevier Ltd.
Bogoda K.R.,Environment Protection Authority
Geotechnical Special Publication | Year: 2016
Design and construction standards of landfills in Victoria, Australia, are subject to specific, outcome-based, liner performance criteria in accordance with the landfill guidelines known as the Best Practice Environmental Management Guideline (Siting, Design, Operation and Rehabilitation of Landfills) (BPEM). Consequently, landfill design and construction standards in Victoria have significantly improved with strictly applied construction quality requirements. The design documents for every new landfill (or landfill cell) need to be approved by the Environment Protection Authority (EPA), the Victorian government regulator, prior to commencing construction. The design documents must include plans, technical specifications and a construction quality assurance (CQA) Plan which are prepared in accordance with the BPEM. In addition to the design documents requiring assessment, the construction needs to be audited by an EPA appointed environmental auditor. While these measures have contributed towards the achievement of highly successful outcomes, these efforts are at times hindered by certain actions-or lack thereof-And have resulted in a number of problems at some landfill sites. Such problems include the inappropriate selection of materials in landfill construction, inappropriate use of vehicles and machinery, the way landfill operation is conducted, the lack of communication and the inexperience of construction staff. While all these problems have been identified and successfully addressed through the EPA's environmental auditing system, such incidents have the potential to hinder improvements in design and construction standards, lead to additional costs and time, and result in increased frustration for all involved. This paper will discuss several of the construction problems which have occurred at certain landfill sites in Victoria and how such incidents have been addressed to ensure appropriate and effective design and construction standards are achieved. © ASCE.
Marchant R.,Museum of Victoria |
Dean J.,Environment Protection Authority
Inland Waters | Year: 2014
Long-term studies have seldom considered the compositional stability (i.e., invariability of community composition) of stream invertebrate communities. Compositional stability could potentially be related to variations in species richness, habitat complexity, or hydrological and physicochemical conditions. Invertebrate species data were obtained for 21 sites that had been sampled over 16 to 20 years in Victoria, southern Australia. Stability of community composition at a site was measured with the mean Bray-Curtis coefficient, which was calculated for all comparisons between samples taken over the sampling period using only presence/absence data. Three datasets were compiled: one containing all species, one containing only insects, and one with family-level data. Multiple regressions demonstrated that stability at a site was related directly to species richness and habitat complexity and inversely to daily discharge; stability was not related to physicochemical conditions. The first 2 factors accounted for 45-49% of the variance while flow accounted for 9-16% but was not significant at the family level. The positive relation between stability and species richness may be due to higher variability in colonization at species-poor sites and thus lower compositional stability, while increased habitat complexity enhances stability by providing more refuges. Increased flow may result in more invertebrate drift and movement and thus lower stability, but the relationship was weak and provided little support to the idea that hydrology is an important ecological characteristic for invertebrates of southern Australian rivers. © International Society of Limnology 2014.