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Marine heatwave conditions in Western Australia marine waters - 20 February 2025
No full textMarine heatwave (MHW) conditions across all Bioregions of Western Australia have eased over the last two weeks. MHW status no longer applies to the majority of the North Coast and West Coast Bioregions. MHW conditions in the Gascoyne and South Coast Bioregion have eased to Category 1 - Moderate
Predator management with a single bait? Use of Eradicat for the simultaneous management of feral cats, red foxes, and wild dogs
No full textContext In Western Australia, there are three invasive predators that require management for agriculture and biodiversity protection, feral cats, wild dogs, and red foxes. These three predators often coexist in the same locality, suggesting potential efficacy gains can be made via simultaneous control. While Western Australian native species have evolved a high tolerance to poison baiting (1080), invasive predators have not. Therefore, landscape-scale baiting is commonly used for predator management. Aims Eradicat baits designed for feral cat control have also been known to be consumed and control wild dogs and foxes. In this trial, we aimed to evaluate Eradicat as an all-predator bait, determine if there is a preferential time for the use of the bait and assess non-target impact(s) of baiting. Methods We aimed to control all three predators on an agricultural property adjacent to a conservation reserve over 16 months with eight baiting events using Eradicat as an all-predator bait. Twenty one Reconyx camera traps monitored some of the baits deployed. Key results A total of 300 baits had a known outcome with minimal uptake by all three predators. Many issues were encountered when working on a smaller-scale including interference with farming activities and management, flash flooding, and non-target uptake of the Eradicat baits. Wetter than anticipated environmental conditions likely increased alternate prey availability, negatively impacting bait uptake. Conclusions More work is required to determine if Eradicat baits can be used as an all-predator bait
BEN Signage Installation Map – City of Stirling (north)
No full textBeach Emergency Number (BEN) Signage Installation Map – City of Stirling (north)https://library.dpird.wa.gov.au/gis_bens/1045/thumbnail.jp
Managing predators on livestock producing properties in South Africa and Western Australia – producer perspectives
No full textContext Predation impacts livestock farming enterprises worldwide. In South Africa and Western Australia, native and non-native predators negatively impact sheep and cattle farming enterprises. Aims We hoped to compare the perspectives on predator impacts of livestock producers in relation to livestock predation in South Africa and Western Australia. Methods Online and in-person surveys consisting of 26 questions were posed to farmers and pastoralists in both countries. The questions related to land ownership, property size, livestock management, predation impact (financial and livestock losses), control of predators, and other impacts on productivity. Key results Livestock production properties are of a similar size and stocking rate in both countries, but Western Australia has some very large stations. Predation impacts on livestock production are felt in both countries, with South Africa having a larger array of predators, resulting in higher financial impacts. Despite control tools being similar in both countries, deployment of the tools differed. Conclusions Losses to predators are higher in South Africa as their predator management is localised and reactive to predation, whereas Western Australia has a proactive landscape-scale approach to predator control through Recognised Biosecurity Groups. Implications Predators impact farming enterprises in both countries, but the number of predators and the use of available control methods influence the level of impact the predators have on the productivity of farms in both Western Australia and South Africa
Salinity in Calcarosols occurs through the presence of sodium, chloride, bicarbonate and sulfate ions, is caused by sodicity, and leads to decreased osmotic potential
No full textContext Salinity occurs in sodic soils in Australia, but its effect in Western Australia is poorly understood.
Aims We determined the cause of salinity, the ions responsible, and their potential significance as constraints to crop growth on sodic soils at Merredin and Moorine Rock.
Methods Soil was collected from 76 profiles to depths of 1.0–1.4 m (388 samples). Samples were analysed for EC1:5, pH, texture, and exchangeable and soluble ions.
Results Exchangeable cations were best calculated as the difference between total cations (determined from BaCl2/NH4Cl extracts) and soluble ions (determined from water-soluble extracts). Profiles showed increasing sodicity, alkalinity and salinity with depth. The major soluble cation responsible for salinity was Na+; the major soluble anions were Cl−, HCO3−, SO42−, and CO32−. High salinity in subsoils (depth \u3e 0.2 m) was strongly correlated with dispersive charge (adj. R2 = 0.73). Osmotic potentials were calculated for two levels of gravimetric soil water, the water content of the soils at sampling, or assuming 30% (dry mass basis) soil water. At Moorine Rock, soils mostly had osmotic potentials less than −1.5 MPa. Increasing soil water content to 30% made osmotic potentials less negative. At Merredin, there was strong stratification of osmotic potentials; surface soils mostly had osmotic potentials between 0 and −0.5 MPa, but subsoils mostly had osmotic potentials between −1.0 and −1.5 MPa.
Conclusions Crop growth in these landscapes is likely to be constrained by salinity, particularly in dry years
Successful artificial incubation and juvenile-rearing of dropped eggs of a critically endangered freshwater crayfish (Cherax tenuimanus)
No full textOne-third of the world’s freshwater crayfish species face extinction risk, necessitating extreme and urgent conservation measures such as captive rearing. Little information exists on these measures for most threatened species. The hairy marron, Cherax tenuimanus (Parastacidae), is a critically endangered freshwater crayfish endemic to the Margaret River in south-western Western Australia. C. tenuimanus is being rapidly replaced by the smooth marron, Cherax cainii, a translocated congener, causing its progressive decline in range, and now it faces imminent extinction in the wild. Attempts at captive breeding have resulted in few occurrences of egg laying of C. tenuimanus, which ended in complete loss of the clutch as eggs were progressively dropped by the female. To assess the potential of dropped eggs in captive rearing, we trialled ex situ artificial incubation techniques by using eggs dropped from a captively held female. Of 41 dropped eggs, 85% were successfully hatched in suspension upwellers, and 74% of the subsequent juveniles were reared successfully for 111 days in a purpose-built recirculating aquaculture system. We describe our protocols and facilities in detail because captive rearing of dropped eggs was demonstrated to be a viable option for improved success of captive reproduction. These approaches may be applicable for conserving similar crayfish species
The first Australian co-invasion of Euwallacea fornicatus, Fusarium sp. [AF18] and Graphium euwallaceae
No full textAs international trade and travel increase around the world, invasive species detections and incursions are increasing in frequency. Here we document the first detection and incursion within Australia by the Polyphagous shot-hole borer (PSHB), Euwallacea fornicatus (Eichhoff, 1868) (Coleoptera: Curculionidae: Scolytinae), an ambrosia beetle, and two of the associated fungal species; Fusarium sp. [AF18], and Graphium euwallaceae. All three exotic species were detected in a confined region within Perth, Western Australia, and represent a co-invasion. This multispecies incursion into one of the world’s most remote cities highlights the rapid increase in biological invasions globally and the pressures that urban, agricultural, and native environments face from invasive species
How to identify leafhoppers
No full textThese tiny plant-feeding insects are often considered pests due to the damage they can inflict on crops and gardens. Leafhoppers, treehoppers and spittlebugs (or froghoppers) are closely related to cicadas, and planthoppers are their more distant relatives. As their names suggest, most of them can hop
Native pasture restoration in the Kimberley rangelands, Western Australia – seed production areas
No full textThe pastoral industry in the Kimberley region is an important economic contributor to Western Australia. However, as a result of past land management practices, there has been a decline of the more desirable native pasture grasses resulting in a loss of feed-base productivity. To reverse this decline, research is being conducted to help restore important native pasture grasses in this region.
In the Kimberley region, access to native grass seed for restoration is limited as wild-harvest is opportunistic, typically un-mechanised and ripe seed collection sites can be difficult to access during the wet season. Establishing a Seed Production Area (SPA) close to existing all weather roads will allow access to seed at the optimum harvesting time, and planting of single species on flat terrain will allow rapid and efficient collection of seed especially if using mechanical harvesters. Also, the use of fertiliser and irrigation could improve seed quality and increase seed production. This should improve the availability and reduce the cost of native grass seed for use in restoration of native grasses to degraded rangelands and mine-sites.
Six native grass species have been planted out on a small scale to trial a SPA located in Perth, Western Australia. Plants were fertilised and irrigated during summer. Plant growth and phenology were monitored and seed quality compared to wild-harvested seed. Irrigation extended the flowering period and hence seed production. Seed fill (a measure of seed viability) from the SPA was equal to or significantly greater than for wild-harvested seed. There was a trend towards increased seed yield and seed fill in the SPA when grasses were cut before summer re-growth, and with increased irrigation
Evaluating Remotely Sensed Spectral Indices to Quantify Seagrass in Support of Ecosystem-Based Fisheries Management in a Marine Protected Area of Western Australia
No full textHighlights What are the main findings? Four spectral indices were identified as important for the quantification of seagrass within and adjacent to the MSC-certified Western Australia Enhanced Greenlip Abalone Fishery. The Normalised Difference Aquatic Vegetation Index (NDAVI) and Depth Invariant Index of the blue and green bands were the most important indices. Similar seagrass cover and distribution were observed inside and outside of the fishery area of operation. What are the implication of the main finding? The use of indices from free satellite products via Google Earth Engine workflows and automatic image annotation provides a rapidly repeatable method to support ecosystem-based fisheries management for this fishery. These findings may have broader applications for ecosystem monitoring across moderately deep (\u3c 20 m) fisheries and marine management areas. Abstract Understanding and monitoring benthic habitat distribution is essential for implementing ecosystem-based fisheries management (EBFM). Satellite remote sensing offers a rapid and cost-effective approach to marine habitat assessments; however, its application requires context-specific adjustment to account for environmental variability and differing study aims. As such, predictor variables must be tailored to the specific site and target habitat. This study uses Sentinel-2 Level 2A surface reflectance satellite imagery and stability selection via Random Forest Recursive Feature Elimination to assess the importance of remote sensing indices for mapping moderately deep (\u3c 20 m) seagrass habitats in relation to the Marine Stewardship Council-certified Western Australia Enhanced Greenlip Abalone Fishery (WAEGAF). Of the seven indices tested, the Normalised Difference Aquatic Vegetation Index (NDAVI) and Depth Invariant Index for the blue and green bands were selected in the optimal model on every run. The kernelised NDAVI and Water-Adjusted Vegetation Index also scored highly (both 0.92) and were included in the final classification and regression models. Both models performed well and predicted a similar cover and distribution of seagrass within the fishery compared to the surrounding area, providing a baseline and supporting EBFM of the WAEGAF within the surrounding marine protected area. Importantly, the use of indices from freely accessible ready-to-use satellite products via Google Earth Engine workflows and expedited ground truth image annotation using highly accurate (0.96) automatic image annotation provides a rapidly repeatable method for delivering ecosystem information for this fishery