Physical Sciences and Mathematics Commons^™

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 …

Rotary Spading To Ameliorate Soil Water Repellence, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

One-off deep cultivation can reduce the severity of soil water repellence by mixing some of the repellent topsoil into the wettable subsoil and bringing wettable subsoil to the surface.

Rotary spading or deep cultivation increases water infiltration by providing pathways for water entry; diluting the water repellent soil with non-repellent soil; increasing the breakdown of soil organic matter causing water repellence; in some soil types, spading and other deep cultivation can lift subsoil with higher clay content to the surface.

Deep cultivation increases the risk of wind and water erosion. To minimise the risk of erosion, follow the guidelines on …

Developing A Controlled Traffic (Tramline) Farming System, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Controlled traffic farming (CTF) is a farming system built on permanent wheel tracks where the crop zone and traffic lanes are permanently separated. It can improve profitability and sustainability.

Implements for seeding, spraying, spreading and harvesting have a particular span, or multiple of it, and all wheel tracks are confined to specific traffic lanes.

CTF increases profit by more yield, better grain quality, improved operation timeliness, and reduced costs. The environment can improve, with less nutrient leaching, less water erosion, better water infiltration, and less greenhouse gas emission. Implementation needs a clear, long-term plan, and prioritisation of soil health.

Another …

Soil Inversion To Ameliorate Soil Water Repellence, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

One-off soil inversion results in the burial of the water repellent topsoil in a layer that is typically a depth of 15 to 35 cm and brings to the surface a layer of wettable subsoil.

Other benefits include burial of herbicide resistant weed seeds, removal of compaction, improved access to nutrients, reduced disease risk, and incorporation of soil amendments such as lime.

Soil inversion should always be done when the soil is wet to more than the depth of inversion, and a crop or cover can be sown to reduce the risk of wind erosion.

Caution - Deep cultivation can …

Ord River Irrigation Area Stage 2 M2 Supply Channel Compliance Assessment Report 2023 - Statement 938, Department Of Primary Industries And Regional Development, Western Australia

Irrigated Agricultural Development in the North

Ministerial implementation Statement 938 for the Ord River Irrigation Area Stage 2 (M2 Supply Channel) proposal was published on 12 June 2013 pursuant to section 45 of the EP Act. DPIRD administers MS938 on behalf of the Minister for Regional Development.

Epbc 2010/5491: Weaber Plain Development Project Compliance Report - 1st May 2023 To 30th April 2024, Department Of Primary Industries And Regional Development, Western Australia

Irrigated Agricultural Development in the North

The Weaber Plain Development Project (Goomig Project) was approved on 13 September 2011. The approval reference is EPBC 2010/5491 (the Approval).

The Goomig Project comprises irrigated farmland, associated infrastructure, and a buffer area on the Weaber Plain located about 30km north-northeast of Kununurra in Western Australia. Figure 1 shows the location and layout of the Goomig Project and interface with other projects including the Knox Creek Plain Irrigation Development (EPBC 2014/7143), Sorby Hills Silver Lead Zinc mining project, and Ord River Irrigation Area (ORIA) Stage 1 'Cave Springs' farms.

The Department of Primary Industries and Regional Development is the Goomig …

Recommendations For The Revision Of Animal Units And Their Application In The Western Australian Rangelands, Ian Mclean, Sally Finch

Natural resources commissioned reports

This report provides recommendations for the practical application of a methodology for calculating and applying Animal Units in the rangelands of Western Australia.

Animal Units have evolved over time, in their definition, derivation and the size of the standard animals used. This has resulted in their being varying and inconsistent approaches within and across jurisdictions which has limited their application.

The Animal Unit methodology applied in this report is used in other rangeland and pastoral regions, it therefore progresses a nationally consistent approach.

The standard animals used in this methodology are:

• Animal Equivalent (AE), a 450 kg Bos taurus steer …

Deferred Grazing And Sheep At The Break Of Season In South West Western Australia, Department Of Primary Industries And Regional Development, Western Australia

Animal production and livestock factsheets

Grazing annual pastures in the first 12 days after germination can lower the productivity of pastures during winter by removing poorly rooted plants, and by reducing plant leaf area to sub-optimal levels. The Department of Primary Industries and Regional Development (DPIRD) recommends deferring grazing of pasture paddocks at the break-of-season until feed on offer is at least 500–800 kilograms of dry matter per hectare (kg DM/ha). At this level, pasture plants are likely to be firmly rooted and have sufficient leaf area to be productively grazed.

Herbicides, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Herbicides play a vital role in integrated weed management programs. Knowledge of the mechanisms and activity of herbicides will improve the impact and sustainability of herbicides as a weed management tactic. This fact sheet is a guide to the types of herbicides available and when and how they should be used.

Herbicide Application, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Herbicides can be applied by a variety of means, including boom sprayers, aerial spraying, misters, blanket wipers, rope wick applicators, weed seekers and back-pack sprayers. This fact sheet reviews the different methods, including nozzles and calibration of equipment, used to apply herbicides.

Grazing Annual Pastures – Using Feed On Offer (Foo) As A Guide, Department Of Primary Industries And Regional Development, Western Australia

Animal production and livestock factsheets

Grazing management in winter and spring in South West Western Australia (SW WA) can manipulate the quality, quantity and composition of pasture. These pasture changes can increase livestock feed efficiency and productivity, reduce insect populations and improve pasture persistence. Seasonal grazing based on feed on offer (FOO) is described here to maximise stocking rate and pasture production.

The Department of Primary Industries and Regional Development recommends using feed measurements and feed budgeting to increase productivity and reduce livestock health risks.

Boosting Winter Pasture Growth, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Applying gibberellic acid or nitrogen fertiliser to pasture in winter can increase dry matter production of grasses and broadleaf weeds and help reduce feed shortages in winter.

Agricultural Groundcover Update May 2024, Justin Laycock

Natural resources published reports

• In May, over 9% (1,410,000 ha) of the arable farmland in the south-west of Western Australia had less than 50% vegetative groundcover, which is inadequate to prevent wind erosion.
• Northern grainbelt had the highest risk of wind erosion and over 26% of this farmland had inadequate groundcover, predominantly found on landscapes known for sandy soils.
• About 1.3% (208,900 ha) of arable land had a high to very high risk of wind erosion because groundcover was less than 30%. Half of this land was in the West Midlands Ag Soil Zone.

Agricultural Groundcover Update April 2024, Justin Laycock

Natural resources published reports

• In April, over 12% (1,876,000 ha) of the arable farmland in the south-west of Western Australia had less than 50% vegetative groundcover, which is inadequate to prevent wind erosion.
• Northern grainbelt had the highest risk of wind erosion and over 26% of this farmland had inadequate groundcover, predominantly found on landscapes known for sandy soils.
• About 1.5% (238,900 ha) of arable land had a high to very high risk of wind erosion because groundcover was less than 30%.

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) …

Identifying High-Value Tactical Livestock Decisions On A Mixed Enterprise Farm In A Variable Environment, Michael Young, John Young, Ross S. Kingwell, Philip E. Vercoe

Animal production and livestock research articles

Context

Australia is renowned for its climate variation, featuring years with drought and years with floods, which result in significant production and profit variability. Accordingly, to maximise profitability, dryland farming systems need to be dynamically managed in response to unfolding weather conditions.

Aims

The aim of this study is to identify and quantify optimal tactical livestock management for different weather-years.

Methods

This study employed a whole-farm optimisation model to analyse a representative mixed enterprise farm located in the Great Southern region of Western Australia. Using this model, we investigated the economic significance of five key livestock management tactics. These included …

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 …

Consultation Summary For Proposed Declared Pest Rates 2024/2025, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity published reports

Before determining a rate, the Minister for Agriculture and Food is required to consult with owners of the land to be rated, as described in the Biosecurity and Agriculture Management (Declared Pest Account) Regulations 2014 (the Regulations).

The annual process for consultation enables the Department of Primary Industries and Regional Development (DPIRD) to gauge landholder perception on the proposed Declared Pest Rate (DPR) in accordance with the Regulations.

Agricultural Groundcover Update March 2024, Justin Laycock

Natural resources published reports

• In March, over 10% (1,577,000 ha) of the arable farmland in the south-west of Western Australia had less than 50% vegetative groundcover, which is inadequate to prevent wind erosion.

• The northern grainbelt had the highest risk of wind erosion and over 20% of this farmland had inadequate groundcover.

• About 1.3% (191,000 ha) of arable land had a high to very high risk of wind erosion because groundcover was less than 30%.

Genomic Population Structure Of Great Hammerhead Sharks (Sphyrna Mokarran) Across The Indo-Pacific, Naomi L. Brunjes, Samuel M. Williams, Alexis L. Levengood, Matt K. Broadhurst, Vincent Raoult, Alastair V. Harry, Matias Braccini, Madeline E. Green, Julia L. Y. Spaet, Michael J. Travers, Bonnie J. Holmes

Fisheries Research Articles

Context

Currently, little information exists describing the population structure of great hammerhead sharks (Sphyrna mokarran) in Australian waters. Aims

This study used single nucleotide polymorphisms to investigate fine-scale population structure in S. mokarran across the Indo-Pacific. Methods

DNA was extracted from 235 individuals across six Australian locations and a Red Sea outgroup. Population parameters were calculated and visualised to test structuring across locations. Key results

No fine-scale population structuring was observed for S. mokarran across the Indo-Pacific. However, population structuring occurred for all Australian locations when compared to the Red Sea outgroup. Conclusions

Findings suggest a single stock …

The Social And Economic Dimensions Of One Of The World’S Longest-Operating Shark Fisheries, Matias Braccini, Maddison Watt, Clinton Syers, Nick Blay, Matthew Navarro, Michael Burton

Fisheries Research Articles

Context

Social and economic information is limited for coastal commercial and recreational fisheries, particularly shark fisheries, which are perceived as unsustainable and as targeting sharks for fins.

Aims

To characterise the social and economic dimensions of one of the world’s few long-standing sustainable shark fisheries.

Methods

We reviewed historic data and surveyed stakeholders to understand the economic and social dimensions of the shark fishery currently operating in Western Australia.

Key results

Since the fishery’s historic peak, there has been a substantial reduction in the number of operating vessels and ports due to management intervention. For the vessels that have remained, …

Agricultural Groundcover Update February 2024, Justin Laycock

Natural resources published reports

• About 92% of the grainbelt had adequate (more than 50%) vegetative groundcover to prevent wind erosion in February 2024.

• Nearly 8% of the grainbelt (1,193,400 ha) had less than 50% groundcover, which is inadequate to prevent wind erosion.

• The northern grainbelt had the highest risk of wind erosion and 16.5% of this farmland had inadequate groundcover.

• Less than 0.7% of the grainbelt had a high to very high risk of wind erosion because groundcover was less than 30%.

Procedures For Rangeland Condition Assessment In The Pilbara And Southern Rangelands 2022, Department Of Primary Industries And Regional Development

Natural resources published reports

To define the procedures used in 2022 by DPIRD to complete rangeland condition assessment (RCA) in the Pilbara and southern rangelands region which has predominantly shrub-based pastures. For the rest of the pastoral estate, DPIRD uses the Procedures for RCA in the Kimberley which has grass pastures.

RCA is the process DPIRD uses to make systematic, lease level assessment of rangeland. Rangeland condition considers both the condition of pastures (as defined in the Pasture condition and management guide for the Pilbara rangelands or Southern rangelands pasture condition and management guides) and soils (as determined by erosion, using the erosion assessment …

Procedures For Rangeland Condition Assessment In The Kimberley 2022, Department Of Primary Industries And Regional Development

Natural resources published reports

This report defines the procedures used in 2022 by DPIRD to complete rangeland condition assessment (RCA) in the Kimberley region which has grass-based pastures. For the rest of the pastoral estate, DPIRD uses the Procedures for RCA in the Pilbara and southern rangelands which have predominantly shrub pastures.

RCA is the process DPIRD uses to make systematic, lease-level assessment of rangeland. Rangeland condition considers both the condition of pastures (as defined in the 'Pasture condition guide for the Kimberley') and soils as determined by erosion, using the erosion assessment method on pastoral lands in Western Australia (WA). The methods have …

Long Term Sustainable Use Of Demersal Gillnet And Demersal Longline In Western Australia’S Temperate Shark Fisheries - Fisheries Research Report 340, Matias Braccini, Jack Parker, Daniela Waltrick, Maddison Watt, Nick Blay, Clinton Syers

Fisheries Research Reports

The Temperate Demersal Gillnet and Demersal Longline Fisheries (TDGDLF) are one of the main commercial shark fisheries in Australia. Most fishers in the TDGDLF use demersal gillnets to target sharks with scalefish taken in smaller amounts. Demersal longlines are also permitted but are not widely used. Demersal gillnets are size selective, but they do not necessarily discriminate among species, catching target and non-target species.

The Western Australian Fishing Industry Council (WAFIC) received funding as part of the Australian Government’s Our Marine Parks Grants Program to undertake research on the TDGDLF. This project was administered under the direction of a steering …

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 …

Fisheries Research Report No. 339: Assessment Of The Status Of The South Coast Demersal Scalefish Resource, Jeffrey V. Norriss, Sybrand A. Hesp, David V. Fairclough, Rubie Evans-Powell, B. Hancock, Emily A. Fisher, Tim Leary, Nick Jarvis

Fisheries Research Reports

This document provides the 2023 risk-based weight of evidence stock assessments for snapper, Bight redfish, hapuku, blue morwong, and Western blue groper for 2023 in the South Coast Bioregion (SCB).

Agricultural Groundcover Update January 2024, Justin Laycock

Natural resources published reports

Summary

• About 94% of the grainbelt had adequate (more than 50%) vegetative groundcover to prevent wind erosion in January 2024.
• In the northern half of the grainbelt, a larger-than-average area has 51–60% groundcover, which is expected to decrease to below 50% over the coming months.
• Just under 6% of the grainbelt (855,000 ha) had less than 50% groundcover, which is inadequate to prevent wind erosion. West Midlands Ag Soil Zone had the highest risk of wind erosion and 14.5% of this farmland had inadequate groundcover.
• Less than 0.5% of the grainbelt had a high to very high risk of wind …

Soil And Fertiliser Management For Orchards In The Manjimup District, Neil Lantzke, Simon Yeap, Lukasz Kotula, B Goldspink, Valeria Almeida Lima, John Kammann

Horticulture research reports

This publication aims to give orchardists a broad understanding of the soils in the Manjimup district. It provides information on soil and fertiliser management that will assist in the sustainable production of fruit crops. This document was prepared for a Soils Course for horticulturalists, that was held in September 2023 at Manjimup Horticultural Research Centre.

The Manjimup local government area (LGA) is the most important horticultural district in Western Australia, particularly for fruit and in 2020 the total value of horticultural production was valued at $236 million (Figure 1). Avocados and apples were the most valuable horticultural crops, valued at …

Weed Seed Wizard Case Study - An Early Harvest Versus A Late Harvest, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity research reports

The Weed Seed Wizard is a national collaborative project that uses paddock management information to predict weed emergence and crop losses now and in the future.

The Weed Seed Wizard is a computer simulation tool that:

• applies to all Australian grain growing areas

• helps growers understand and manage weed seedbanks on their farms

• uses farm management records to simulate how different crop rotations, weed control techniques, irrigation, grazing and harvest management tactics can affect weed numbers, the weed seedbank and yields

• uses farm-specific management and site-specific weather

• is multi-species

See www.dpird.wa.gov.au for further information on Weed Seed Wizard.

This case …