Physical Sciences and Mathematics Commons^™

Low-Emission Beef Production In The Southern Rangelands Of Western Australia: An Analysis Of Herd Structure And Stocking Rate Experiencing Droughts, Christophe D'Abbadie

Animal Production and Livestock Research Articles

Reconciling profitable cattle production with rangeland health and reduced emissions is a key challenge in the southern rangelands of Western Australia (WA). Stocking rate and herd structure selection are crucial decisions to achieve this balance. This study assessed the emission profiles of three contrasting herd structures (weaner production, live export, and slaughter production), and three stocking rates within a herd–carbon accounting modelling framework. The analysis considers the impact of varying drought frequencies on these cattle production systems. Herd models were developed for the semiarid southern WA rangelands. Stocking rates were set at 100%, 80% and 66% of the government recommended …

Density-Dependence Inside A Marine Protected Area Increases Natural Mortality And Stunts The Growth Of A Spiny Lobster, Simon De Lestang, Emma Jade Tuffley

Fisheries Research Articles

Sustainable fisheries management often requires the modelling of stocks under unfished conditions, when the influence of population densities on animal growth and mortality can be substantial. This can be especially true for species such as spiny rock lobster, which are very habitat specific. Using western rock lobster (Panulirus cygnus) tag-recapture data from adjacent and similar fished and unfished areas, the key life history parameters of natural mortality and growth were examined and compared under different population density scenarios. In an area representative of virgin biomass levels, lobsters exhibited reduced growth rates and a substantially higher rate of natural mortality …

Revealing The Impact Of Spatial Bias In Survey Design For Habitat Mapping: A Tale Of Two Sampling Designs, Stanley Mastrantonis, Tim J. Langlois, Ben Radford, Claude Spencer, Simon De Lestang, Sharyn Hickey

Fisheries Research Articles

Submerged aquatic vegetation, referring to benthic macroalgae and plants that obligately grow underwater, are critical components of marine ecosystems and are frequently found to provide preferential recruitment habitats. The mapping and monitoring of aquatic vegetation through remote sensing and machine learning is becoming an important aspect of managing coastal environments at scale. Accurate mapping and monitoring require robust sampling and occurrence data to assess predictive error and quantify submerged vegetation extents. The form of ground truthing survey design (preferential, random, grid-based or spatially balanced) could significantly influence predictive model outcomes and the overall accuracy of mapping and monitoring. Here, we …

Heavy Steers And Heifers Run At Low Stocking Rates Enhance Drought Resilience In A Pastoral Region Of Australia, Christophe D'Abbadie, Ross Kingwell, Philip E. Vercoe, Bradley Plunkett, Alan Peggs

Animal Production and Livestock Research Articles

CONTEXT

The semi-arid mulga lands of the Southern Rangelands of Western Australia experience frequent droughts. Maintaining a profitable animal grazing enterprise whilst preserving rangeland condition requires selecting an appropriate stocking rate and herd structure.

OBJECTIVE

We construct and apply bioeconomic models of beef enterprises for the semi-arid Southern Rangelands of Western Australia, to assess the profitability and relative riskiness of three different livestock production systems and three different stocking rates when exposed to different frequencies of drought.

METHODS

We construct bio-economic models of herd structures that separately focus on producing either: (i) 200 kg heifers and 210 kg steers (ii) …

Including Methane Emissions From Agricultural Ponds In National Greenhouse Gas Inventories, Martino E. Malerba, Tertius De Kluyver, Nicholas J. Wright, Odebiri Omosalewa, Peter I. Macreadie

Climate Science Research Articles

Agricultural ponds are a significant source of greenhouse gases, contributing to the ongoing challenge of anthropogenic climate change. Nations are encouraged to account for these emissions in their national greenhouse gas inventory reports. We present a remote sensing approach using open-access satellite imagery to estimate total methane emissions from agricultural ponds that account for (1) monthly fluctuations in the surface area of individual ponds, (2) rates of historical accumulation of agricultural ponds, and (3) the temperature dependence of methane emissions. As a case study, we used this method to inform the 2024 National Greenhouse Gas Inventory reports submitted by the …

Trends In Catch Rates Of Sawfish On The Australian North West Shelf, C. Wakefield, S. J. Newman, M. Braccini, A. Harry

Fisheries Research Articles

Northwestern Australia is thought to have some of the world’s last remaining viable sawfish populations, although little quantitative data exists on their status or trends. This study examined 17 years of logbook bycatch records (n = 815) for green sawfish Pristis zijsron and narrow sawfish Anoxypristis cuspidata from a trawl fishery operating on the Australian North West Shelf. Incidental sawfish captures by the fishery are rare, occurring approximately once every 75 trawls (~199 trawl hours). To standardize catch rates and account for excess zeros in the data, we employed generalized additive models for location, scale, and shape (GAMLSSs) using a …

State Of The Fisheries: Status Reports And Aquatic Resources Of Western Australia 2022/23, S.J. Newman, K.G. Santoro, D.J. Gaughan

Status reports of the fisheries and aquatic resources

Aquatic resources within Western Australia (WA) are in good condition, and this has positioned WA as a global leader in sustainable fisheries management. The sustainable fisheries of WA continue to support our strong economy and regional communities. Nonetheless, the lack of a consistent approach to build in the knowledge of Traditional Owners remains a gap in our longer term fisheries science in Western Australia.

Climate change and climate variability continues to impact fish stocks, challenging our ability to effectively monitor, assess, and manage fish stocks. We are continually working with our stakeholders, and the broader community to be adaptive, responsive, …

How Sensitive Are Catchment Runoff Estimates To On-Farm Storages Under Current And Future Climates?, David E. Robertson, Hongxing Zheng, Jorge L. Pena-Arancibia, Francis H S Chiew, Santosh Aryal, Martino E. Malerba, Nicholas J. Wright

Climate Science Research Articles

Storage of water in farm dams is important to support irrigation, stock requirements and domestic uses when reticulated water is unavailable. Farm dams that fill by intercepting landscape runoff change the total volume and seasonality of catchment streamflow, potentially impacting water policy outcomes. While numerous studies have quantified how climate change and farm dams independently change streamflow characteristics, few studies have investigated their interactions. This study investigates the interactions between farm dams and climate change in the Murray-Darling Basin of southern and eastern Australia. We use hydrological modelling that explicitly represent farm dams and remotely sensed data describing historical farm …

State Of The Fisheries: Status Reports And Aquatic Resources Of Western Australia 2021/22, Department Of Primary Industries And Regional Development, Western Australia, S J. Newman, B S. Wise, K G. Santaro, D J. Gaughan

Status reports of the fisheries and aquatic resources

Aquatic resources within Western Australia (WA) are in good condition, and this has positioned WA as a global leader in sustainable fisheries management. The sustainable fisheries of WA continue to support our strong economy and regional communities. Nonetheless, the lack of a consistent approach to build in the knowledge of Traditional Owners remains a gap in our longer-term fisheries science in Western Australia.

Climate change and climate variability continues to impact fish stocks, challenging our ability to effectively monitor, assess, and manage fish stocks. We are continually working with our stakeholders, and the broader community to be adaptive, responsive, and …

Methane Emissions From Agricultural Ponds Are Underestimated In National Greenhouse Gas Inventories, Martino E. Malerba, Tertius De Kluyver, Nicholas J. Wright, Lukas Schuster, Peter I. Macreadie

Climate Science Research Articles

Agricultural ponds have some of the highest methane emissions per area among freshwater systems, and these anthropogenic emissions should be included in national greenhouse gas inventories. Here we deliver a continental-scale assessment of methane emissions from agricultural ponds in the United States and Australia. We source maps of agricultural ponds, compile a meta-analysis for their emissions and use published data to correct for temperature and the relative contributions of two methane fluxes (diffusion and ebullition). In the United States, 2.56 million agricultural ponds cover 420.9 kha and emit about 95.8 kt year−1 of methane. In Australia, 1.76 million agricultural ponds …

Emissions Baseline Report For The Agriculture Sector In Western Australia, Mandy Curnow, Christophe D'Abbadie, Bob French, Jackie Bucat, Dario Stefanelli, Neil Lantzke, Valeria Almeida Lima, Jess Austen, Lee Chester, Kate Pritchett, Millie Brady, Dylan Bennett

Natural resources research reports

The Intergovernmental Panel on Climate Change Sixth Assessment Report found that climate impacts are appearing earlier and are more severe than expected. The world faces multiple unavoidable climate hazards over the next two decades with global warming of 1.5ºC and accelerated action is required to avoid mortality and loss of biodiversity and infrastructure.

Achieving Climate Resilience requires both climate adaptation and mitigation of Greenhouse Gases which are accelerating climate change. Western Australia is committed to building resilience of the agriculture industry and as part of that is focussed on reducing greenhouse gas (GHG) emissions at both an industry and government …

Maximization Of Fitness By Phenological And Phenotypic Plasticity In Range Expanding Rabbitfishes (Siganidae), Salvador Zarco-Perello, David Fairclough, Chris Dowling, Joey Dibattista, Rachel Austin, Thomas Wernberg, Brett Taylor

Fisheries Research Articles

1. Global warming is modifying the phenology, life-history traits and biogeography of species around the world. Evidence of these effects have increased over recent decades; however, we still have a poor understanding of the possible outcomes of their interplay across global climatic gradients, hindering our ability to accurately predict the consequences of climate change in populations and ecosystems.
2. We examined the effect that changes in biogeography can have on the life-history traits of two of the most successful range-extending fish species in the world: the tropical rabbitfishes Siganus fuscescens and Siganus rivulatus. Both species have established abundant populations at higher …

Sediment Budgets For Small Salinized Agricultural Catchments In Southwest Australia And Implications For Phosphorus Transport, Robert J. Wasson, David Weaver

Natural Resources Research Articles

Examples of sediment budgets are needed to document the range of budget types and their controls. Sediment budgets for three small agricultural catchments (7.6 to 15.6 km2) in southwestern Australia are dominated by channel and gully erosion, with sheet and rill erosion playing a subordinate role. Erosion was increased by clearing naturally swampy valley floors and hillslopes for agriculture and grazing, and episodic intense rainstorms. The proportion of sediment from channel and gully erosion in the sediment budget appears to be determined by the depth of alluvial fills. Dryland salinization caused by clearing native vegetation has connected hillslopes to channels …

Climate-Assisted Persistence Of Tropical Fish Vagrants In Temperate Marine Ecosystems, Laura Gajdzik, Thomas M. Decarlo, Adam Koziol, Mahsa Mousavi-Derazmahalleh, Megan Coghlan, Matthew W. Power, Michael Bunce, David Fairclough, Michael J. Travers, Glenn I. Moore, Joseph D. Dibattista

Fisheries Research Articles

Rising temperatures and extreme climate events are propelling tropical species into temperate marine ecosystems, but not all species can persist. Here, we used the heatwave-driven expatriation of tropical Black Rabbitfish (Siganus fuscescens) to the temperate environments of Western Australia to assess the ecological and evolutionary mechanisms that may entail their persistence. Population genomic assays for this rabbitfish indicated little genetic differentiation between tropical residents and vagrants to temperate environments due to high migration rates, which were likely enhanced by the marine heatwave. DNA metabarcoding revealed a diverse diet for this species based on phytoplankton and algae, as well …

A Continental-Scale Assessment Of Density, Size, Distribution And Historical Trends Of Farm Dams Using Deep Learning Convolutional Neural Networks, Martino E. Malerba, Nicholas J. Wright, Peter I. Macreadie

Climate Science Research Articles

Farm dams are a ubiquitous limnological feature of agricultural landscapes worldwide. While their primary function is to capture and store water, they also have disproportionally large effects on biodiversity and biogeochemical cycling, with important relevance to several Sustainable Development Goals (SDGs). However, the abundance and distribution of farm dams is unknown in most parts of the world. Therefore, we used artificial intelligence and remote sensing data to address this critical global information gap. Specifically, we trained a deep learning convolutional neural network (CNN) on high-definition satellite images to detect farm dams and carry out the first continental-scale assessment on density, …

Status Reports Of The Fisheries And Aquatic Resources Of Western Australia 2020/21, S.J. Newman, B.S. Wise, K.G. Santoro, D.J. Gaughan

Status reports of the fisheries and aquatic resources

The Status Reports of the Fisheries and Aquatic Resources of Western Australia (SRFAR) provide an annual update on the state of the fish stocks and other aquatic resources of Western Australia (WA). These reports outline the most recent assessments of the cumulative risk status for each of the aquatic resources (assets) within WA’s six Bioregions using an Ecosystem Based Fisheries Management (EBFM) approach. The Departments’ risk based EBFM framework is the State government’s basis for management of all Western Australia’s aquatic resources.

The Development And Application Of Functions Describing Pasture Yield Responses To Phosphorus, Potassium And Sulfur In Australia Using Meta-Data Analysis And Derived Soil-Test Calibration Relationships, Cameron J P Gourley, David Weaver, Richard J. Simpson, Sharon R. Aarons, Murray M. Hannah, Ken I. Peverill

Natural Resources Research Articles

An improved ability to predict pasture dry matter (DM) yield response to applied phosphorus (P), potassium (K) and sulfur (S) is a crucial step in determining the production and economic benefits of fertiliser inputs and the environmental benefits associated with efficient nutrient use. The adoption and application of soil testing can make substantial improvements to nutrient use efficiency, but soil test interpretation needs to be based on the best available and most relevant experimental data. This paper reports on the development of improved national and regionally specific soil test–pasture yield response functions and critical soil test P, K and S …

Identifying Groundwater - Dependent Wetlands Of The Broome Sandstone Aquifer In The La Grange Groundwater Area, Nicholas Wright, Richard J. George Dr, Robert Paul, Paul Raper

Resource management technical reports

This report identifies wetlands that are likely to be dependent on the Broome Sandstone aquifer within the La Grange groundwater allocation area. The Broome Sandstone aquifer is the dominant groundwater resource in the area. With potential agricultural growth of this area, it is necessary to understand, monitor and manage the aquifer and its dependent wetlands. This report describes how we created a watertable surface that was used to identify wetlands and to determine which of the previously mapped wetlands are likely to be sourced from the Broome Sandstone aquifer. A watertable surface was created from 148 points taken from bore …

Climate In The Pilbara, Robert Sudmeyer

Bulletins 4000 -

The Pilbara is characterised by very hot summers, mild winters and low and variable rainfall. It is classified as hot desert in northern and inland areas and hot grasslands in the north-west. The Pilbara claims a number of climate records:

• seven of Western Australia’s top 10 hottest days, with Mardie recording the hottest day on record — 50.5 degrees Celsius (°C)
• most sunshine hours a day in Australia (more than 10 hours a day)
• second highest inter-annual variability in rainfall (second only to central Australia)
• the most cyclone-prone area along the Australian coastline.

During summer and early autumn (December to …

Cockatoo Sands In The Victoria Highway And Carlton Hill Areas, East Kimberley: Hydrogeology, Aquifer Properties And Groundwater Chemistry, D L. Bennett, John Andrew Simons, Richard J. George Dr, Paul Raper

Resource management technical reports

Cockatoo Sands are recognised as potentially suitable for irrigated agriculture because they are generally well drained and not subject to waterlogging or inundation. These characteristics allow them to be cultivated and prepared for planting various crops during the wet and dry seasons of northern Australia. Expanding agricultural production onto the Cockatoo Sands around Kununurra will increase opportunities for agriculture by increasing the overall scale of agriculture, allowing year-round agricultural enterprise, new crops and new market opportunities.

DAFWA has assessed the soil characteristics and agriculturally suitable areas of Cockatoo Sands in the Victoria Highway and Carlton Hill areas near Kununurra. Potential …

Groundwater Chemistry Of The Weaber Plain (Goomig Farmlands): Baseline Results 2010–13, Adam Lillicrap, Richard J. George Dr, Arjen Ryder, D L. Bennett

Resource management technical reports

The Ord River Irrigation Area (ORIA) is located in the north-east of the Kimberley region of Western Australia, near the town of Kununurra. The irrigation area was established in 1963 and over time developed to the current extent of 14 000 hectares (ha). The Weaber Plain (Goomig Farmlands) area is located north-north-east of the existing irrigation area, 30km from Kununurra, and has been identified as being suitable for irrigated agriculture for many decades. However, it was not until 2009, with state government support, that the 7400ha project commenced, with construction starting in 2010. State and Australian government environmental approvals required …

Contrasting Environmental Drivers Of Adult And Juvenile Growth In A Marine Fish: Implications For The Effects Of Climate Change, Joyce Jia Lin Ong, Adam Nicholas Rountrey, Jessica Jane Meeuwig, Stephen J. Newman, Jens Zinke, Mark Gregory Meekan

Fisheries Research Articles

Many marine fishes have life history strategies that involve ontogenetic changes in the use of coastal habitats. Such ontogenetic shifts may place these species at particular risk from climate change, because the successive environments they inhabit can differ in the type, frequency and severity of changes related to global warming. We used a dendrochronology approach to examine the physical and biological drivers of growth of adult and juvenile mangrove jack (Lutjanus argentimaculatus) from tropical north-western Australia. Juveniles of this species inhabit estuarine environments and adults reside on coastal reefs. The Niño-4 index, a measure of the status of …

Growth Of A Deep-Water, Predatory Fish Is Influenced By The Productivity Of A Boundary Current System, Hoang Minh Nguyen, Adam N. Rountrey, Jessica J. Meeuwig, Peter G. Coulson, Ming Feng, Stephen J. Newman, Anya M. Waite, Corey B. Wakefield, Mark G. Meekan

Fisheries Research Articles

The effects of climate change on predatory fishes in deep shelf areas are difficult to predict because complex processes may govern food availability and temperature at depth. We characterised the net impact of recent environmental changes on hapuku (Polyprion oxygeneios), an apex predator found in continental slope habitats (>200 m depth) by using dendrochronology techniques to develop a multi-decadal record of growth from otoliths. Fish were sampled off temperate south-western Australia, a region strongly influenced by the Leeuwin Current, a poleward-flowing, eastern boundary current. The common variance among individual growth records was relatively low (3.4%), but the …

Salinity Risk Mapping For Assessing Carbon Farming Initiative Proposals: Decision Support And Data Requirements, Paul Raper, Peter Gardiner

Resource management technical reports

The Clean Energy Legislation passed by the Australian Parliament on 8 November 2011 links the carbon price to the Carbon Farming Initiative (CFI). Under the Carbon Credits (Carbon Farming Initiative) Act 2011 (the Act), proponents need to consider regional natural resource management (NRM) plans to ensure that tree plantings for carbon bio-sequestration maximise environmental benefits and avoid unintended adverse effects on biodiversity, water and agricultural production systems.

Guidance Statement On Undertaking Seismic Surveys In Western Australian Waters, Department Of Fisheries

Fisheries occasional publications

No abstract provided.

Pastoral Lease Assessment Using Geospatial Analysis, T P. Robinson, P E. Novelly, R Corner, Philip Thomas, A Russell-Browm

Resource management technical reports

Seven remote sensing based Vegetation Indices (NDSVI, STVI-3, NDVI, Green + Red, Red, Land Monitor and STVI-1) were tested for their potential to discriminate between “poor” and “good” range condition assessments in Western Australia’s pastoral rangelands. Indices were computed using the Australian Greenhouse Office National Carbon Accounting System (AGO NCAS) repository of calibrated Landsat TM/ETM+ mosaics. Discrimination potential was assessed at two levels of stratification – station level (identical to the stratification used to collect the traverse data), and functional group level (an aggregation of similar land systems);

Bait Effects In Sampling Coral Reef Fish Assemblages With Stereo-Bruvs, Stacey R. Dorman, Euan S. Harvey, Stephen J. Newman

Fisheries Research Articles

Baited underwater video techniques are increasingly being utilised for assessing and monitoring demersal fishes because they are: 1) non extractive, 2) can be used to sample across multiple habitats and depths, 3) are cost effective, 4) sample a broader range of species than many other techniques, 5) and with greater statistical power. However, an examination of the literature demonstrates that a range of different bait types are being used. The use of different types of bait can create an additional source of variability in sampling programs. Coral reef fish assemblages at the Houtman Abrolhos Islands, Western Australia, were sampled using …

Observations Of Localised Effects Of The Busselton Compensating Basins On Surface Water, Groundwater And Soil Salinity, D L. Bennett, Richard J. George Dr

Resource management technical reports

Between 2001 and 2009 the Water Corporation constructed three flood-compensating basins on farmland in the Vasse and Sabina river catchments, upstream of in the city of Busselton. The basins are designed to reduce the risk of flooding in urban areas of Busselton by temporarily storing and then regulating runoff during flood events. This report fulfils the reporting requirements of a contract between the Water Corporation and the Department of Agriculture and Food. Data relating to the local groundwater and surface-water dynamics, salinity, nutrients and pH, plus changes to shallow and deep-soil salinity (from repeat ground-based electromagnetic induction [EM] surveying), was …

Agriculture Futures: Potential Rural Land Uses On The Palusplain, Rodney Safstrom, Nicolyn Short Dr

Resource management technical reports

The purpose of this project was to identify agricultural land use options and opportunities within the Serpentine–Jarrahdale and Murray Shires, with particular focus on the Palusplain wetland section. The report will contribute to the Department of Planning’s natural resource management plan for the region and guide development of regional and local planning strategies. Historically, the Palusplain was a slowly moving, interconnected, seasonal wetland system with areas of higher ground. Extensive clearing and drainage occurred in the late 1800s through to the mid-1900s to facilitate agriculture; however, agriculture has been found to be a major contributor of nutrients to the system. …

Groundwater Chemistry Of The Weaber Plain: Preliminary Results, Adam Lillicrap, Paul Raper, Richard J. George Dr, D L. Bennett

Resource management technical reports

In 2008, the Ord Irrigation Expansion Project was approved by the Western Australian Government to develop irrigated agriculture on the Weaber Plain. Construction of the M2 supply channel connecting the ORIA and the Weaber Plain, and the final period of irrigation design, environmental management and related approval processes, commenced later in 2009. This process followed a protracted period of public and private industry planning and environmental assessment (Kinhill 2000). This report summarises an analysis of groundwater salinity trends on the Ivanhoe and Weaber plains and the preliminary results of an intensive water-quality sampling program carried out in 2010 as part …