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Economic impact of polyphagous shot hole borer Euwallacea fornicatus (Coleoptera: Curculionidae: Scolytinae) in Western Australia
No full text1. Following the discovery of polyphagous shot hole borer Euwallacea fornicatus (Eichhoff) in Western Australia in September 2021, we estimated the likely economic damage that will result in the coming decades and the return on investment in eradication. 2. A bioeconomic model was used to simulate the insect\u27s spread and economic impact based on additional urban and commercial tree management costs. Two scenarios were examined, one in which an eradication policy response was initiated, and one in which it was not. 3. With no eradication response, results indicated that median costs would reach A45.0 million over 3 years, will not generate sufficient benefits to offset costs in the short-term, but may produce net benefits in the longer term
High performance of a low input, mixed western Australian farming system: public policy implications from the case of Tolga farm
No full textTolga is a 5,200 ha sheep and cropping farm located near Kulin in Western Australia (WA). Since 2004, its production system has been a blend of conventional and alternative practices; some of these alternative practices are common in non-broadacre industries. The alternative practices are based on an understanding of soil health gained from the Australian Soil Planners system which aims to improve the farm’s biological functioning and nutrient cycling.
This includes use of phase rotations with legume (subclover) pastures tended as a crop, minimal, but necessary synthetic fertilisers and chemicals, supplementary nutritional packages for pastures, animals, and soils, supplementing chemical control with nutrition and grazing management where possible, corrective liming to address soil acidity, and using deep rooted tillage radish to recycle sub soil nutrients, promote root biomass to reduce the impact of soil compaction and possibly, reduce enteric methane emissions.
Livestock performance is very high by industry standards, and crop yields, previously similar to district average, are improving in response to a greater proportion of the farm dedicated to livestock / pasture production. The reasons for the high level of livestock performance are not thoroughly understood, emphasising the need for research into the farm’s system. Estimated profitability is around the median of a leading consultant’s cohort of farmers for that rainfall zone; however, the low variability in its profit is reflective of the top 25% of the cohort, ranked on profit (gross margin) per hectare. The business has steadily grown over the past 30 years. Emissions (T/CO2e/ha) are estimated to be low compared to industry benchmarks and evidence exists that the farm’s total organic carbon pool is either reflective of or is as much as 40% higher than the surrounding area
Genomic analyses indicate two blue swimmer crab species in Australia, evidence for natural interspecific hybridization and genetic structure within species with implications for fisheries management and stock enhancement
No full textBlue swimmer crab species are widely distributed in Indian and west Pacific Oceans including the coastline around Australia and have been identified as potential candidates for stock enhancement. A recent taxonomic review revealed the presence of two blue swimmer crab species in Australia, namely Portunus armatus which is found around most of the Australian coastline, and Portunus pelagicus which is found in the northern coast where it is sympatric with P. armatus. It is important to understand population structure and genetic diversity of Portunus spp. to efficiently manage stocks. In the present study we investigated species classification and population structure of Portunus spp. in Australia using full and partial genomic information, namely mitochondrial COX1 gene sequences derived from whole genome sequencing and single nucleotide polymorphic (SNP) markers developed from partial genome sequencing. Blue swimmer crab samples were collected from the western (n = 52), northern (n = 17) and eastern (n = 110) coasts of Australia. Genetic diversity and population genetic structure were assessed for within and between region variation. Our genomic results indicated the presence of two blue swimmer crab species in Australia. One, namely, P. pelagicus was found only in Northern Territory (Darwin), and other, namely P. armatus was found around Australia. There was evidence of natural hybridisation between two species in Northern Territory (Darwin) where they were sympatric. P. armatus populations from the western, northern and eastern regions were genetically different although there were no significant genetic differences observed between the Queensland and New South Wales populations nor between the two neighbouring populations in Western Australia. Results found in the present study supports the view that the P. armatus populations in western, northern and eastern regions of Australia should be treated as at least three different stocks. A lack of genetic structuring along the eastern coast suggests blue swimmer crabs can be considered as a single stock along the sampled range at least in relation to fisheries enhancement, release programs and broodstock management
Length and age compositions, hermaphroditic traits and reproductive characteristics vary among five congeneric species of labrid in a large embayment
No full textThis study explored the extent to which the hermaphroditic and reproductive characteristics vary among five congeneric (Choerodon) and co-occurring species of the Labridae, a family in which hermaphroditism is widespread. Sampling was located in the large sub-tropical Shark Bay (26° S, 113° E), one of only twenty World Heritage Properties in Australia. Choerodon cephalotes, C. cyanodus, C. cauteroma and C. schoenleinii live within the main body of the embayment, which approaches the southern limit of their tropical, geographical ranges, whereas C. rubescens lives along its outer western boundary, close to the northern limit of its warm, temperate distribution. A combination of comprehensive length and age compositions, histological analyses of gonads and logistic regressions of lengths and ages at maturity and sex change are consistent with all five species being monandric protogynous hermaphrodites. Choerodon cephalotes, C. rubescens and C. schoenleinii are sexually dichromatic, with the lengths and ages of males at the extreme upper end of those of females and low proportions of males among adults (adult sex ratios, ASR: 11–33%). It is proposed that these species have polygynous mating systems, such as leks or harems. Although C. cauteroma has an ASR of essentially parity, its pronounced sexual dichromatism and the ages of its males typically lying at the upper end of those of its females indicate that this species also has a polygynous mating system. Limited sexual dichromatism and an ASR as high as 71% suggest that C. cyanodus is not polygynous. As the timing of the main spawning period of the four species within Shark Bay increases sequentially between early spring and late summer, the temperature trigger for spawning by those species also presumably increases progressively. This phasing of spawning, allied with some interspecific spatial variation, reduces the potential for competition among the larvae and early juveniles of the five Choerodon species. Choerodon rubescens spawns earlier in Shark Bay than in the cooler waters of the Abrolhos Islands, 230 km further south. The management implications of data for Choerodon species, and particularly of the size compositions and the ASRs of the two largest species, C. rubescens and C. schoenleinii, are discussed. The variations in the hermaphroditic and reproductive features of five congeneric species of labrid, in the region in which their distributions overlap, highlight the evolutionary/biological plasticity of this family and thereby contributes to its diversity and success
Field Trials Report 2023: WA Farming Systems Project
No full textWithin the Western Australian Faming Systems Project, a program of 15 field trials were conducted in 2023 from Ogilvie in the north to Wittenoom Hills in the south. Despite a dry season all trials were implemented effectively such that all multi-year trials are set to investigate their associated research questions
BEN Signage Installation Map – City of Joondalup (south)
No full textBeach Emergency Number (BEN) Signage Installation Map – City of Joondalup (south)https://library.dpird.wa.gov.au/gis_bens/1009/thumbnail.jp
BEN Signage Installation Map - Shire of Northampton
No full textBeach Emergency Number (BEN) Signage Installation Map – Shire of Northamptonhttps://library.dpird.wa.gov.au/gis_bens/1049/thumbnail.jp
Agronomic soil tests can be used to estimate dissolved reactive phosphorus loss
No full textContext: Phosphorus (P) use in agriculture can lead to eutrophication. Agronomic soil tests such as Colwell P and P buffering index (PBI) define critical soil P levels for pasture production. These tests have potential for re-use as environmental risk indicators of dissolved reactive P (DRP) loss from paddocks but are constrained because a 0–10 cm sample does not necessarily align with the dominant hydrological loss pathways of runoff or leaching. Aims: To identify influences on the benchmark environmental measure of DRP (CaCl2-extractable P or CaCl2-P) by agronomic-based measures such as PBI, Colwell P and depth, and Colwell P to PBI ratio (P environmental risk index; PERI). To estimate CaCl2-P at any depth from a 0–10 cm sample, and the potential for change in DRP loss risk through the adoption of evidence-based fertiliser management based on soil testing. Methods: Archives of 692 0–10-cm soil samples, along with 88 sites sampled at 0–10 cm and 0–1, 1–2, 2–5, 5–10, 10–20, and 20–30 cm were analysed for Colwell P, PBI, CaCl2-P, PERI, and P fertility index (PFI). Derived relationships between CaCl2-P and Colwell P for different PBI were applied to 30 981 0–10-cm samples to estimate the potential for DRP reduction resulting from the adoption of evidence-based fertiliser management. Key results: CaCl2-P, Colwell P, PERI, and PFI decreased with depth, with an associated increase in DRP loss risk from surface soil. The CaCl2-P decreased with increasing PBI. The CaCl2-P, Colwell P, PERI, and PFI could be estimated at any depth from a 0–10 cm sample, with r2 \u3e 0.77. The CaCl2-P was estimable from PERI, and soils with low PBI or with high PFI had high DRP loss risk. The CaCl2-P was positively correlated with Colwell P, with the slope decreasing with increasing PBI and becoming invariant when PBI \u3e 100. When applied to the current soil Colwell P and estimated current CaCl2-P and compared to CaCl2-P at the critical Colwell P for different relative yields (RYs), DRP loss risk could be reduced by 24% for a RY target of 95%, and 59% for a RY target of 80%. Conclusions: Because current Colwell P levels in soils exceed critical values, DRP loss risk can be substantially reduced by adopting evidence-based fertiliser management with little or no loss of utilised pasture. Implications: Fertiliser management based on evidence of P requirements determined from soil testing has a significant role in reducing DRP loss risk
Blow flies (Diptera: Calliphoridae) ability to pollinate Hass avocado trees within paired tree enclosures
No full textAvocado pollination remains a major focus for producers as fruit-set is typically very low (less than 1%). Most avocado producers in Australia utilize honey bees (Apis mellifera) to improve yield; however, there are risks with reliance on one species for future pollination security. Flies regularly visit flowers including avocado flowers. However, their pollination ability is poorly understood. To address this, visual observations of flies foraging in avocado orchards along with releases of two species of blow fly (within replicate enclosures of paired avocado trees; Hass and Type B cultivars) were conducted at a commercial orchard in south-western Western Australia. Visual observations during flowering identified that most non-bee flower visits were by hover flies (Melangyna viridiceps and Sphaerophoria macrogaster) and blow flies (Calliphora vicina and C. albifrontalis). Hover flies mostly foraged on flowers in the morning while blow flies were generally more active in the afternoon. Pollination as measured by harvestable fruit was higher by C. dubia (45.6 ± 10.0) than by C. albifrontalis. (26.3 ± 6.6). Compared with open trees pollinated by bees and other insects present, trees pollinated by C. dubia produced nearly two-thirds the number of fruit. When presented with equal numbers of avocado flowers, C. dubia fed three times more often than C. albifrontalis, which may explain their higher pollination rate. Both C. dubia and C. albifrontalis transferred on average one pollen grain/flower visit. Blow flies improved avocado yield above no insect pollinators (3 fruit/tree) by an average of 31 fruit/tree (across both fly species), but considerably less than trees in the open pollinated by honey bees (128 fruit/tree). Future trials with multi-tree enclosures will assess avocado pollination by different fly species. This study demonstrated that at least one species of blow fly could pollinate avocado and provide potential as a managed pollinator in Australian horticulture
Initial impacts of the COVID-19 pandemic on Australian fisheries production, research organisations and assessment: shocks, responses and implications for decision support and resilience
No full textAustralia’s fisheries have experience in responding individually to specific shocks to stock levels (for example, marine heatwaves, floods) and markets (for example, global financial crisis, food safety access barriers). The COVID-19 pandemic was, however, novel in triggering a series of systemic shocks and disruptions to the activities and operating conditions for all Australia’s commercial fisheries sectors including those of the research agencies that provide the information needed for their sustainable management. While these disruptions have a single root cause—the public health impacts and containment responses to the COVID-19 pandemic—their transmission and effects have been varied. We examine both the impacts on Australian fisheries triggered by measures introduced by governments both internationally and domestically in response to the COVID-19 pandemic outbreak, and the countermeasures introduced to support continuity in fisheries and aquaculture production and supply chains. Impacts on fisheries production are identified by comparing annual and monthly catch data for Australia’s commercial fisheries in 2020 with averages for the last 4–5 years. We combine this with a survey of the short-term disruption to and impacts on research organisations engaged in fisheries monitoring and assessment and the adaptive measures they deployed. The dominant impact identified was triggered by containment measures both within Australia and in export receiving countries which led to loss of export markets and domestic dine-in markets for live or fresh seafood. The most heavily impact fisheries included lobster and abalone (exported live) and specific finfishes (exported fresh or sold live domestically), which experienced short-term reductions in both production and price. At the same time, improved prices and demand for seafood sold into domestic retail channels were observed. The impacts observed were both a function of the disruptions due to the COVID-19 pandemic and the countermeasures and support programs introduced by various national and state-level governments across Australia to at least partly mitigate negative impacts on harvesting activities and supply chains. These included protecting fisheries activities from specific restrictive COVID-19 containment measures, pro-actively re-establishing freight links, supporting quota roll-overs, and introducing wage and businesses support packages. Fisheries research organisations were impacted to various degrees, largely determined by the extent to which their field monitoring activities were protected from specific restrictive COVID-19 containment measures by their state-level governments. Responses of these organisations included reducing fisheries dependent and independent data collection as required while developing strategies to continue to provide assessment services, including opportunistic innovations to harvest data from new data sources. Observed short run impacts of the COVID-19 pandemic outbreak has emphasised both the vulnerability of fisheries dependent on export markets, live or fresh markets, and long supply chains and the resilience of fisheries research programs. We suggest that further and more comprehensive analysis over a longer time period of the long-run impacts of subsequent waves of variants, extended pandemic containment measures, autonomous and planned adaptive responses would be beneficial for the development of more effective counter measures for when the next major external shock affects Australian fisheries