Groundwater ecosystems, are among the environments with limited accessibility for research, posing significant challenges for proper investigation, especially of their rare fauna. Studies of species such as the blind cave gudgeon (Milyeringa veritas), which is restricted in its distribution to groundwater systems of the Cape Range Peninsula (North-Western Australia), are constrained by both logistical and conservation considerations. Here we aimed to assess population structure in M. veritias using genome complexity reduction-based sequencing (DArTseq) analyses for 30 individuals from coastal areas of the Cape Range Peninsula. Preliminary Single Nucleotide Polymorphism ordination analyses identified four genetically distinct populations in discrete geographic regions of Cape Range. Further, to evaluate the applicability of environmental DNA (eDNA) in population-level inference for this species, the hypervariable region 1 (HVR1) of the mitochondrial D-loop was also analysed for the same specimens. The HVR1 dataset yielded a population structure broadly consistent with that inferred from genome-wide markers. These results reveal complex patterns of gene flow and population isolation within the groundwater systems of the Cape Range Peninsula, likely shaped by reduced connectivity through the cave network and historical periods of isolation. The DArTseq dataset provides valuable genomic evidence of fine-scale population structure, contributing critical information for the conservation management of Milyeringa veritas. In addition, the concordance between genome-wide and mitochondrial d-loop (HVR1) signals suggests that targeted eDNA approaches may offer a cost-effective, non-invasive proxy for monitoring population structure in cryptic and vulnerable groundwater taxa.

Landscape connectivity plays a crucial role in maintaining gene flow and the long-term survival of threatened species. As habitat fragmentation intensifies, gene flow between populations diminishes, especially when species cannot overcome unsuitable areas between habitat patches. This is particularly critical for species like the endangered Broad-toothed Rat, which has a patchy distribution across south-eastern Australia. Despite their ability to disperse over several hundred meters, these rats face significant challenges, such as habitat loss, predation by feral cats
and foxes, and habitat degradation and fragmentation. Further, dispersal is limited where riparian vegetation is lacking, and changes in vegetation structure can impede movement following disturbances from fire and intrusion by feral horses.
Using Single Nucleotide Polymorphisms (SNPs) derived from tissues samples collected across Northern Kosciuszko National Park, this study explored the level of geneflow and connectivity of broad-toothed rat populations. Using a combined analytical approach of landscape genetics, circuit theory and least-cost pathways, we aimed to determine how genetic structure within this landscape is affected by environmental factors such as development and feral horses. The outcomes will enhance our understanding of broad-toothed rats dispersal capabilities in horse-
dominated landscapes, providing valuable insights into the species; persistence under changing disturbance regimes. This information is crucial for guiding conservation efforts and mitigating the ongoing threats to BTR populations.

The impact of human activities are accelerating biodiversity loss, demanding monitoring tools that can be deployed widely to generate rigorous and standardized data for biodiversity monitoring. Environmental DNA (eDNA) analysis offers a non-invasive monitoring approach and fulfils many of these requirements, but its effectiveness depends on methodologies, such as sample concentration techniques. In this study, we introduce QuickConc, a highly sensitive and on-site eDNA concentration method that utilizes benzalkonium chloride (BAC) in combination with dispersed glass fibers to enhance the sensitivity of detection. Species-specific qPCR results showed that QuickConc detected 2 to 10 times higher copy numbers than the conventional methods (glass fiber filter and Sterivex), suggesting its potential to enhance eDNA concentration efficiency and enable more stable detection of rare species with low populations. QuickConc was originally designed for on-site manual filtration, so processing sample volumes larger than 2 liters was difficult. To overcome the challenge of processing large-volume water samples, we further developed QuickConc Vacuum, which integrates vacuum filtration with the QuickConc method, enabling efficient processing of large volumes of water. We demonstrated the effectiveness of QuickConc Vacuum through evaluations conducted in both aquarium and marine environments using metabarcoding and qPCR. Metabarcoding analysis using MiFish primers confirmed significantly greater fish species relative to the conventional methods, and total eDNA yield increased proportionally with filtered volume. In conclusion, the QuickConc and QuickConc Vacuum methods represent a significant advancement, providing a powerful and environmental monitoring tool. This technology facilitates the efficient processing of varied water volumes, enhancing the detection of rare and non-indigenous species and offering a valuable tool for ecological research and management in the face of ongoing environmental change.

The koala (Phascolarctos cinereus) is an iconic and well-studied Australian marsupial, but the species presents a complex case for conservation. Currently, most koala conservation efforts focus on local-scale population estimates, which are often based on expert opinion or anecdotal evidence, and either precede or exclude available data. In contrast, conservation listing advice and associated recovery plans require population estimates at the species-range scale.

The National Koala Monitoring Program has developed a data-driven, national-scale population estimate to guide effective management of koala populations by providing high-quality and objective information. The model results indicate that there are more koalas than previously estimated on a national scale.

It also indicates that the distribution of koalas is patchy throughout much of eastern Australia with some areas of high density and the rest of the population is dispersed in low density across large areas. We explore some of the nuances of the modelled spatial results and discuss potential explanations, consequences of past actions and implications for koala conservation.