Fitzroy Basin Research Articles

Setting restorative goals with a regional outlook: Mine-rehabilitation outcomes influence landscape connectivity

Mining is increasing worldwide and is typically associated with highly negative environmental impacts, such as habitat loss and fragmentation. To counteract these effects and improve restoration practices, decisions, such as setting mine rehabilitation goals, could incorporate the assessment and restoration of landscape connectivity into their regional and local-scale planning. The overarching goal of this work was to assess landscape connectivity for flora and fauna and explore mine-rehabilitation scenarios that can be used as a tool for prioritising biodiversity outcomes. Our study area comprised the Fitzroy Basin (Queensland, Australia), where the disturbance footprints from mining cover a cumulative area of 121,239 ha. We considered two scenarios: rehabilitation to agriculture and restoration to native ecosystems. To compare these scenarios, we created differential maps, which highlighted that restoring to native ecosystems represented connectivity gains over agricultural rehabilitation goals. These maps revealed three ways to prioritise rehabilitation outcomes, giving priority to mines that: 1) presented medium to high connectivity values, 2) covered a large area of influence (contributing to connectivity on a larger scale, regardless of current flow values), and 3) showed a gain of important paths/corridors. We explored four case studies and found that three benefited from restoration outcomes, while the fourth did not benefit by either scenario. Our methods can be used for decision-making in restoration ecology and conservation, including mine rehabilitation priorities and goals, as well as for evaluating connectivity gains or losses.

Analyzing the Influence of Climate Variables on Native Pasture Phenology in the Fitzroy Basin, Australia

Remote-sensing-based approaches to determining phenological parameters can help ascertain growing seasonality parameters and provide valuable insights into the growth dynamics of vegetation. Using native pastures as the vegetation type, this study aims to analyze variations and trends in the timing of the start of season (SOS) and the end of season (EOS), using Moderate Resolution Imaging Spectroradiometer data. The Fitzroy Basin in Queensland was selected as eleven-year case study, with the 2009 through 2020 period used for data acquisition and analysis. Four climatic variables—rainfall, temperature, humidity, and solar radiance data sources from climatic stations—were used to analyze the relationship between SOS and EOS. Sensitivity analysis based on multilayer perceptron neural network models was carried out to reveal the relative influence of climatic variables on SOS and EOS. Findings show that SOS and EOS trends are insignificant for most areas. Both of the phenological metrics are highly sensitive to rainfall. Fluctuation of rainfall has influence on the timing of seasonal parameters. Humidity and solar radiance, however, also appear to be a major influence for EOS. These findings can assist in providing information pertaining to pasture management strategies in anticipation of extreme climate conditions.

Agricultural Use Report Card development: A case study in the Fitzroy Basin, Queensland

Agriculture is heavily reliant on readily available water of a suitable quality for stock consumption and irrigation of crops. While technical methods for assessing water quality are available, methods to summarise the results and communicate it to a broader audience are lacking. Here the development of an Agricultural Use Report Card in the Fitzroy Basin, Queensland, is outlined. This study summarises findings and includes a methodology developed and deployed to deliver these stock and crop water suitability assessments. We also discuss the index developed to underpin agricultural use, report card publication and communication, along with the online assessment architecture used to facilitate multi-tier result interrogation by end users. This study found surface waters of the Fitzroy were generally of good or very good quality for agricultural uses. Occasional exceedances of agricultural suitability thresholds for several indicators were identified, and we discuss the method used for exceedance identification and a novel style of exceedance reporting that provides a greater degree of transparency than traditional aquatic ecosystem report card approaches.

Aridification‐driven evolution of a migratory fish revealed by niche modelling and coalescence simulations

AbstractAimMajor knowledge gaps exist regarding the evolution of arid zone organisms. For freshwater species with high dispersal potential, little is known if historical aridification influenced connectivity across drainage divides and impacted on their divergence and diversification. We tested the hypothesis that the historical aridification of Australia promoted the isolation and influenced the demographic histories and evolutionary divergence of a migratory group of freshwater obligates.LocationCentral and eastern Australia; Murray–Darling Basin (MDB), Lake Eyre Basin (LEB), Fitzroy Basin (FIT).TaxonThree lineages of golden perch (Macquaria ambigua), a widespread fishery resource from inland Australia.MethodsWe obtained genome‐wide data for golden perch sampled throughout their range. Phylogenetic relationships were reconstructed using maximum likelihood. Species distribution modelling was used to predict contemporary and past distributions for the three lineages and to develop hypotheses regarding their biogeographic and demographic histories. Hypotheses were independently tested using coalescent simulations in fastsimcoal and DIYABC with the genomic dataset.ResultsWe found evidence for three reciprocally monophyletic lineages that have experienced little to nil genetic connectivity since divergence. Coalescent models suggest that the coastal (FIT) and inland (MDB and LEB) lineages diverged ~103 thousand years ago (ka), followed by the split of MDB and LEB lineages ~58 ka. These timings agree with reductions of large freshwater environments in Australia during the late Pleistocene. Species distribution models show an extreme decrease in habitat during the Last Glacial Maximum ~21 ka, consistent with inferred demographic contractions in coalescent tests.Main conclusionsWe reveal that aridification of Australia during the late Pleistocene has driven and reinforced the divergence of a migratory freshwater obligate. Our findings are important for informing the conservation management of aquatic organisms under climate change. This work further demonstrates the value of using species distribution modelling to formulate diversification hypotheses and to improve interpretation of coalescent analyses.

Leichhardt, land clearing and livestock: the legacy of European agriculture in the Brigalow Belt bioregion of central Queensland, Australia

Context The Brigalow Belt bioregion of central Queensland has been extensively developed for agriculture since exploration by Leichhardt in 1844. About 4.5 million hectares of vegetation dominated by brigalow (Acacia harpophylla) was cleared as part of the Land Development Fitzroy Basin Scheme, which commenced in 1962. When the Vegetation Management Act 1999 commenced, 93% of brigalow woodland had been cleared. Grazing is the dominant land use in the Fitzroy Basin, with 2.6 million cattle over 11.1 million hectares (72% of the catchment area). This is the largest cattle herd in any natural resource management region in Australia, accounting for 25% of the state herd and 11% of the national herd. Aims The Fitzroy Basin, Queensland’s largest coastal catchment, drains directly to the Great Barrier Reef, and as reef health continues to decline, there has been increased focus on the impacts of land-use change and grazing management on hydrology and runoff water quality. The Brigalow Catchment Study sought to determine the impact of land clearing, land-use change and land management on hydrology, soil fertility, water quality and animal production in the Fitzroy Basin. Methods The study is a paired, calibrated catchment study. Catchment hydrology, soil fertility, water quality and agricultural productivity were monitored before and after land clearing and land-use change. Key results The Brigalow Catchment Study has shown that clearing brigalow for grazing in the Fitzroy Basin doubled runoff, increased peak runoff rate by 50% and increased total suspended solid loads by 80%. Soil fertility and pasture productivity also declined under grazing compared with brigalow. Overgrazing exacerbated these results, as failure to reduce stocking rate with reduced pasture productivity more than tripled runoff, peak runoff rate and total suspended solid load compared with conservatively grazed pasture. Conclusions This study demonstrates the impacts of land-use change and land management on hydrology, soil fertility and water quality. The long-term data records are a model in their own right, capable of answering land-use and land-management questions beyond the initial study scope. Implications Sustainable grazing management should consider the production limitations of depleted soil and pasture resources to minimise land degradation.

Hydrology and runoff water quality from three improved pastures compared with virgin brigalow (

The Fitzroy Basin in central Queensland has the largest cattle herd of any natural resource management region in Australia, and legumes have been widely used to boost fertility of rundown soil and improve cattle liveweight gains. However, there is a paucity of information on the effect of leguminous pastures on hydrology and water quality. This study investigated runoff water quality over eight hydrological years from virgin brigalow (Acacia harpophylla) woodland and three improved pastures, namely, buffel grass (Pennisetum ciliare), butterfly pea (Clitoria ternatea) and leucaena (Leucaena leucocephala). Runoff event mean concentrations and loads of total and dissolved nitrogen, phosphorus, and carbon in addition to total suspended solids are reported. Brigalow woodland had the greatest loss of sediment and nitrogen attributed to the inherently fertile Vertosols (clay soil), but the low occurrence and amount of runoff meant that it had a low risk to water quality. Despite a similar number of runoff events from the improved pastures, leucaena pasture had less total runoff and a lower maximum peak runoff rate in addition to lower nitrogen and carbon in runoff. Total suspended solids and carbon in runoff were greater from grass pasture than from the leguminous pastures, whereas nitrogen and phosphorus were greatest from the butterfly pea pasture, especially in the first 2 years post-planting. Greater exports of phosphorus from the improved pastures were concerning, given the potential for downstream impacts.

Variations in wetland conditions within the Fitzroy Basin, north-eastern Australia: a palaeoecological approach

The North-east Australian Coastal Catchments (NACC) are host to nationally significant wetland complexes, many of which, are ecologically connected to the Great Barrier Reef World Heritage area. However, these wetlands are subject to ongoing and increasing pressure from human activities such as the intensification of land use. Current wetland condition is monitored across the NACC, being assessed against a pre-development static baseline, which includes the use of Regional Ecosystem mapping of remnant and pre-clearing vegetation to provide a broadscale present-day biotic reference. Two sediment cores from wetlands within the Fitzroy Basin were analysed to establish a history of wetland variability and to identify the potential influence of climate and land-use changes over the past ~1000 years. Our results have provided long-term environmental reconstructions, showing wetland histories influenced by natural climate variability (El Niño–Southern Oscillation, the Little Ice Age), and environmental changes associated with European land-use intensification. This study is the first of its kind for wetlands located within the Fitzroy Basin.

Heavy grazing of buffel grass pasture in the Brigalow Belt bioregion of Queensland, Australia, more than tripled runoff and exports of total suspended solids compared to conservative grazing

Loss of sediment and particulate nutrients in runoff from the extensive grazing lands of the Fitzroy Basin, central Queensland, continue to contribute to the declining health of the Great Barrier Reef. This study measured differences in hydrology and water quality from conservative and heavy grazing pressures on rundown improved grass pastures in the Fitzroy Basin. Conservative grazing pressure was defined as the safe long-term carrying capacity for rundown buffel grass pasture, whereas heavy grazing pressure was defined as the recommended stocking rate for newly established buffel grass pasture. Heavy grazing of rundown pasture resulted in 2.5 times more bare ground and only 8% of the pasture biomass compared to conservative grazing. Heavy grazing also resulted in 3.6 times more total runoff and 3.3 times the peak runoff rate compared to conservative grazing. Loads of total suspended solids, nitrogen and phosphorus in runoff were also greater from heavy than conservative grazing.

Revealing and Revelling in the Floods on Country: Memory Poles within Toonooba

Revealing and Revelling in the Floods on Country: Memory Poles within Toonooba

Coal mine-affected water releases, turbidity and metal concentrations in the Fitzroy River Basin, Queensland, Australia

Historical water quality datasets from the Fitzroy Basin, a large river system that receives mine-affected water from more than 40 mines, and drains into the Great Barrier Reef Lagoon, were analysed. There is great public and environmental interest in these waters that are used for agriculture, recreation and raw drinking water supplies. Aside from one AMD-impacted area, waters were generally alkaline. Turbidity data regularly exceeded the regional water quality objective (< 50 NTU), indicating the presence of particulates that may accumulate or transport metal contaminants within the waters. Analyses of data for 14 metals showed dissolved Cu and Al, followed by Zn, were the parameters that were most often greater than Australian toxicant guideline values. Analysis of coal mine-affected water samples and the receiving creek data, showed that median turbidity was greater downstream than upstream of the mine water release points, suggesting release-water may contain particulate-bound metals. Median dissolved Al and Cu concentrations were lower downstream than upstream and were above guidelines. Preliminary modelling using WHAM7 suggested downstream dissolved Cu (2–5 µg/L) was bound to fulvic acid and was likely not bioavailable. Dissolved Al (170–550 µg/L) may have existed as Al(OH)4−. Overall, suspended particulate matter appeared to be a water quality parameter of interest in this mine-affected river basin. Further targeted sampling, direct measurement of particulate-bound metals and multivariate statistical analysis are needed to help better understand metal partitioning in these turbid, alkaline waters.

The influence of riparian vegetation on water quality in a mixed land use river basin

AbstractWorldwide, agricultural activities are associated with environmental impacts including riparian degradation and increased waterway pollution. The Fitzroy Basin of Central Queensland lies within the Brigalow Belt Bioregion, which is currently experiencing the highest rates of tree clearing in Australia driven by grazing activities, and this is likely to increase riparian degradation. Local riparian condition, however, has not been consistently monitored within the Fitzroy Basin, and its relationship with water quality has not been well established. This study assessed riparian condition of waterways in the Fitzroy Basin using two established scoring methods (the Rapid Appraisal of Riparian Condition and the Australian Rivers Assessment System Habitat Assessment) and statistically investigated the relationship between stream water quality and local riparian condition. Twelve sites in six waterways were sampled four times over two years, during ambient (nonflood) conditions. Upstream creeks with poorer riparian condition had elevated dissolved organic carbon (DOC), dissolved manganese, sulfate, and total nitrogen (TN) concentrations. High concentrations of these water quality variables were associated with poor local riparian scores in principal components analysis. Dissolved manganese and sulfate were included in the multiple regression model for riparian scores (r values: 0.83 to 0.86; p &lt; 0.001), and DOC and TN were very significantly negatively correlated with riparian scores (r values: −0.55 to −0.69; p &lt; 0.001). Overall, the results suggest that protecting riparian vegetation in the Fitzroy Basin and restoring degraded riparian zones could aid in improving water quality in waterways within this region.

Application of Magnetic Resonance Data for Groundwater Prospectivity in The Fitzroy Basin, Western Australia

In the Fitzroy Basin of Western Australia, both ground and borehole Nuclear Magnetic Resonance (NMR) techniques have been applied during a groundwater prospectivity assessment of the Cenozoic sediments, and the Palaeozoic and Mesozoic sandstone aquifers. Ground magnetic resonance (GMR) data was acquired at ten sites from the within the basin and the data was inverted to obtain estimates of the one-dimensional water content for the top 100m. Where these sites were co-located with boreholes, the results were consistent with inverted borehole NMR data and other litho-stratigraphic information although with a reduced horizontal resolution. Both the GMR and borehole data suggest that the Palaeozoic Grant Group and Poole Sandstone have high water content and have the potential to be highly productive aquifers. Furthermore GMR can be used estimate the depth to water table for unconfined aquifer, using 5 volume % as the threshold for saturated zone.

Potential for biomonitoring metals and metalloids using fish condition and tissue analysis in an agricultural and coal mining region

Agricultural and mining activities contribute to metal inputs in freshwater ecosystems around the world, which can in turn bioaccumulate in biota such as fish. Monitoring of metals loads in biota thus provides insight into the concentrations of bioavailable metals within the environment. Little research has been conducted on the potential of Australian freshwater fish for biomonitoring metals. Within the Fitzroy Basin of Central Queensland, a major agricultural and coal mining region, three commonly-encountered fish taxa were analysed for tissue metal loads. Arsenic concentrations in Nematalosa erebi and Melanotaenia splendida splendida tissue were elevated (above Food Standards Australia and New Zealand (FSANZ) guidelines), with highest concentrations in N. erebi liver tissue (up to 5.14 μg/g). Lead concentrations were above the FSANZ guidelines in all three fish taxa analysed, with highest concentrations in Hypseleotrid full-body tissue (up to 5.99 μg/g). Selenium in M. s. splendida and N. erebi tissue was positively correlated with total selenium in water (p < 0.05; r = 0.68 and 0.87 respectively). Environmental boron, selenium and nickel concentrations were positively correlated with N. erebi liver tissue metals. N. erebi hepatosomatic index was negatively correlated with dissolved arsenic, manganese, and total phosphorus (in water). The results highlight that M. s. splendida and N. erebi yield bioindicators which are responsive to environmental metals, and thus have potential for use in biomonitoring metals. The two species are also widespread along the east coast of Australia, there is thus a strong potential for applying the results to other regions within Australia.

Ecosystem Services Mapping Uncertainty Assessment: A Case Study in the Fitzroy Basin Mining Region

Ecosystem services mapping is becoming increasingly popular through the use of various readily available mapping tools, however, uncertainties in assessment outputs are commonly ignored. Uncertainties from different sources have the potential to lower the accuracy of mapping outputs and reduce their reliability for decision-making. Using a case study in an Australian mining region, this paper assessed the impact of uncertainties on the modelling of the hydrological ecosystem service, water provision. Three types of uncertainty were modelled using multiple uncertainty scenarios: (1) spatial data sources; (2) modelling scales (temporal and spatial) and (3) parameterization and model selection. We found that the mapping scales can induce significant changes to the spatial pattern of outputs and annual totals of water provision. In addition, differences in parameterization using differing sources from the literature also led to obvious differences in base flow. However, the impact of each uncertainty associated with differences in spatial data sources were not so great. The results of this study demonstrate the importance of uncertainty assessment and highlight that any conclusions drawn from ecosystem services mapping, such as the impacts of mining, are likely to also be a property of the uncertainty in ecosystem services mapping methods.

The cost effectiveness of remediating erosion gullies: a case study in the Fitzroy

ABSTRACTGrazing in the Fitzroy region has reduced ground cover and increased the exposure of erosion features to terrestrial water flows, resulting in gullies. The run-off that results from such soil degradation has led to elevated levels of sediment in the Great Barrier Reef, adversely affecting the health of the reef. Strategies to reduce gully erosion include: decreasing stocking rates on grazing land, revegetation of erosion features and the implementation of specific infrastructure including fencing and earth works. Using data provided by the Fitzroy Basin Association Inc., this paper presents a case study of the cost effectiveness of gully remediation at six properties across the Fitzroy. Our results reveal a broad range of cost effectiveness among these sites, highlighting the importance of both the selection of policy mechanism and the need for targeted remediation measures. The pattern of cost effectiveness for these sites also raises the possibility of economies of scale in gully work, which could indicate funding advantages from targeting projects that address large volumes of gully erosion. Finally, the magnitude of the costs per unit of sediment reduction at these sites indicates the need to consider a broad spectrum of policy responses to reduce sediment export to the reef.

Rainfall contributes ~ 30% of the dissolved inorganic nitrogen exported from a southern Great Barrier Reef river basin

A study was conducted to estimate how much of the annual load of dissolved inorganic nitrogen (DIN) from Great Barrier Reef (GBR) river basins could come from rainfall. Results suggest rainfall contributed ~37% of the average annual DIN load from the Fitzroy Basin over three wet seasons. Rainfall DIN contribution at plot to sub-catchment scale ranged from 5 to >100% for study sites in the Fitzroy and Pioneer Basins. An estimate using measured and modelled data indicates ~28% of the longer-term average annual DIN load from the entire GBR catchment may originate from rainfall. These estimates may affect current GBR management and water quality targets. Numerous studies predict increases in atmospheric nitrogen pollution from Asia via fossil fuel combustion and more frequent severe La Nina events via global warming. Future GBR rainfall chemistry data may be required for assessing catchment management outcomes and regional trends in atmospheric DIN deposition.

Can paddock scale data integration achieve more cost effective outcomes in the Great Barrier Reef? A case study in the Fitzroy Basin

The decline in health of the Great Barrier Reef and the pressure on allocating funds efficiently has increased efforts to prioritise where public funds are invested. The Fitzroy basin and coastal catchments is 152,000 square kilometres and geographically diverse. Past work has identified that sediment loads leaving the catchment are posing a high risk to the ongoing health of the Reef and that there is a need to prioritise funds to achieve cost effective outcomes. In this paper we aim to present an alternative approach to effective prioritisation of sediment reductions. The approach integrates spatial information regarding the sediment source and process, levels of adoption, bare ground cover, and cost into a function to rank neighbourhood catchments. The results demonstrate the complexity of the issue and the challenge the Fitzroy Basin Association faces when allocating funds. They also illustrate that there are effective opportunities in particular priority areas within the catchment in which on-ground actions could be undertaken, proving it to be a useful approach in prioritising future investments aimed at achieving cost effective sediment reductions to the Reef.

An Ecosystem Health Index for a large and variable river basin: Methodology, challenges and continuous improvement in Queensland’s Fitzroy Basin

Report cards are an increasingly popular method for summarising and communicating relative environmental performance and ecosystem health, including in aquatic environments. They are usually underpinned by an Ecosystem Health Index (EHI) that combines various individual indicators to produce an overall ecosystem health “score”. As a result of public water quality concerns, an integrated means of monitoring and reporting on aquatic ecosystem health was needed for the Fitzroy Basin in central Queensland, Australia. The Fitzroy Partnership for River Health was formed to address this need, and developed an EHI and report card for the Basin using existing monitoring data collected from various third parties including regulated companies operations and government. At 142,000 square kilometres, the Fitzroy Basin is the largest catchment draining to the World Heritage Listed Great Barrier Reef. The Fitzroy Basin provides an example of how to deliver an effective aquatic ecosystem health reporting system in a large and complex river basin. We describe the methodology used to develop an adaptive EHI for the Fitzroy Basin that addresses variability, complexity and scale issues associated with reporting across large areas. As well, we report how to manage the design and reporting stages given limitations in data collection and scientific understanding.

Spatial assessment of open cut coal mining progressive rehabilitation to support the monitoring of rehabilitation liabilities

Worldwide coal mining has expanded over the past few decades, though growth has recently slowed due to reduced demand, partly due to concerns around CO2 emissions and climate change impacts. Coal mining is also a significant driver of land disturbance in regions where economic coal seams and coal mining methods are applied, in particular open cut extraction. To address these impacts, mined landscapes are rehabilitated with the aim of making them safe, stable, non-polluting and self-sustainable to an agreed post-mining land use such as agriculture or conservation. Progressive rehabilitation is often conducted to keep the footprint of disturbance to a minimum and to ensure that ecological and/or agricultural land use production is restored as soon as possible in preference to waiting until after mine closure. Environmental regulators require methods for tracking the performance of mining companies engaging in progressive rehabilitation to evaluate the success or otherwise of their regulatory frameworks and to ensure companies meet the requirements of their environmental authorities or mining licenses.In this study, we describe a spatial method for assessing mine disturbance and rehabilitation regionally and analyse our results in terms of rehabilitation liability. We first developed a land cover classification framework for mapping mining impacts and rehabilitation that categorises land cover using a mining land cover disturbance typology. We then used the Fitzroy Basin in Australia as a case study, utilising the land cover classification scheme to map 37 open cut-coal mines, using manual interpretation of remote sensing data. By comparing the percentage area of rehabilitation with the total mine area we assessed the variability in progressive rehabilitation for the 37 mines. For example, older mines which have a history of progressive rehabilitation should have large areas and a high proportion of area rehabilitated. Finally, we calculated a range of regional rehabilitation liabilities by applying two publically available rehabilitation cost-calculators to the land cover data. We calculated the rehabilitation liability as ranging from $2.7 to $5.5 billion Australian dollars. The lower and upper bounds of the estimate reflect the uncertainty associated with the range of land use types and potential rehabilitation methods, from simple to more complex rehabilitation methods. We conclude by discussing how the methods could be used to support effective decision making by government agencies regulating and monitoring mining activities.

The Cost Effectiveness of Remediating Erosion Gullies in the Fitzroy Basin

The Cost Effectiveness of Remediating Erosion Gullies in the Fitzroy Basin