In order to ascertain whether introduced weeds have an effect on naturally occurring aquatic fauna, this study assesses the toxicity of 3 introduced weeds that occur along the banks of rivers and ponds in New South Wales, on 4 aquatic invertebrates. Damsel Fly nymphs, Mud Eyes, Mayfly nymphs and Backswimmers were placed in petri dishes with minced leaves from either Crofton Weed, Camphor Laurel or Privet (tests), Black Wattle or Derris dust (comparisons) or no plant material (control). The toxicity of the weeds was determined by the lifespan of the invertebrates exposed to them. Damsel Fly nymphs were adversely affected by Camphor Laurel, Crofton Weed and Derris dust, but not the other treatments. Mud Eyes were most affected by Black Wattle and Crofton Weed, though results were variable and inconclusive. Mayfly larvae were most affected by Crofton Weed and Derris dust. Backswimmers were killed very quickly by all three test weeds and Derris dust. These results show differential toxic effects of the three weeds on different invertebrates, suggesting that the distribution and abundance of aquatic invertebrates may be significantly influenced by the presence of toxic weeds along the waterway. These results add to the understanding of negative impacts of bank disturbance which leads to weed infestation of stream banks.

The New South Wales South Western Slopes bioregion has been significantly altered by agricultural development and is likely to experience additional significant impacts as a result of anthropogenic climate change. A simple inventory survey of the vertebrate fauna of Currawananna State Forest, a small woodland remnant on the Murrumbidgee River in the south of the bioregion, over the period 2002-2010 identified 172 vertebrate fauna species. This included three species of national conservation concern (the Trout Cod Maccullochella macquariensis , Murray Cod Maccullochella peelii and Superb Parrot Polytelis swainsonii ) and another 16 species (5 fishes, 8 birds and 3 mammals) of state-level concern, as well as diverse frog, reptile, woodland and wetland bird and microchiropteran bat assemblages. This study demonstrates that even small remnants play an important role in supporting biodiversity in agricultural landscapes.

The disruption of endocrine systems due to environmental contaminants potentially impacts on developmental, behavioural, regulatory, and reproductive systems of wildlife. A major source of exposure of wildlife (terrestrial and aquatic) to endocrine disrupting compounds is through contact with contaminated surface waters. Current testing routines in aquatic systems have not been designed specifically to assess endocrine disruption properties or, alternatively, methods tend not to be fully developed. An alternative approach is to use a response sensitive to these chemicals such as gonopodium length in the pest species Gambusia holbrooki as an indicator. This species was used as a surrogate for native aquatic species to assess endocrine disruption in wetlands that are used for the storage of stormwater or treated sewage effluent. These were compared with adjacent wetlands used for watering stock (farm dams) that were not contaminated with these pollutants. Deformities in the mosquito fish were found that were consistent with endocrine disruption caused by sex steroids and/or their mimics in the first in the sequence of each pollution type but not in farm dams. We concluded that the first wetland in the sequence of recycling stormwater or treated sewage effluent could cause detrimental effects to wildlife but not in subsequent wetlands in a sequence of water storage systems. Since all waters are moved through at least three wetlands before being used for irrigation, or released into the river system, the impact on wildlife is likely to be minimal beyond the first wetlands.

The gobiid, Acentrogobius pflaumii , was recorded in Cockburn Sound in southwestern Australia in 2004, and is now reported for the first time from the Swan River Estuary ca. 20 km north of the initial collection site. It was observed by SCUBA divers on open, soft/silt substrata and was abundant in areas of the middle Swan River Estuary. Ballast water emissions from a nearby international port, containing eggs and/or fish, are considered the most likely introductory vector. Although the ichthyofauna of the Swan River Estuary has been frequently surveyed, it is difficult to speculate how long A. pflaumii has occurred in southwestern Australia because most surveys have not targeted small, cryptic species. The population increase and spread of A. pflaumii in eastern Australia and New Zealand infer that further range expansions in southwestern Australia are likely.

ABSTRACT The perceived dilemma about Dingoes overly simplifies a complex “wicked problem”. Similarly, it is simplistic to suggest that to “cull, contain or conserve” Dingoes are mutually exclusive options or are the only options for managing Dingoes at a state-wide level. The legal instruments enacted and implemented in New South Wales (NSW) attempt to accommodate conflicting values, impacts and drivers. Since the first Dingo symposium in 1999, there has been a series of legislative changes pertaining to Dingo management. That legislation, and associated regulation and policy, addresses the management of Dingoes and other free-roaming dogs such that the dilemma is perceived rather than actual. The main new legal operand in New South Wales is the Biosecurity Act 2015, but other States have similar legislation. Here we outline the application of this Act and others to the management of Dingoes in NSW and conclude that they can be variously culled, contained and conserved, within and across large landscapes, depending on context and managers’ objectives.

Introduced species have made a major contribution to the degradation of aquatic wetlands throughout the world and particularly in Australia. One species, Red-Eared Slider Trachemys scripta elegans , classified among the world's top 100 most invasive pest species, has established populations in Australia, most extensively in South-eastern Queensland. A decade ago a small established population was identified in a wetland in Southern Sydney in Yeramba Lagoon. We re-visited this population a decade on to determine its status and the impact on the two resident native freshwater turtle species, Chelodina longicollis Eastern Long Necked Turtle and Emydura macquarii dharuk Sydney Basin Turtle. We captured similar numbers of red-eared sliders as a decade before but increased number of the two native species. There was therefore no indication that the feral species was currently at a competitive advantage over the native species.

ABSTRACT In Australia, the common carp ( Cyprinus carpio ) is a significant pest species because it dominates fish communities in numerous catchment areas. In 2016, Australia launched a national control plan based on the use of Cyprinid herpesvirus 3 (CyHV3) to reduce carp densities. CyHV3 is exotic to Australia and is listed as by the World Organization for Animal Health (OIE) due to its substantial impact on global aquaculture production. Infection with CyHV3 causes koi herpesvirus disease (KHVD), a high mortality disease in common carp affecting all age classes of both wild and farmed fish. The objective of this review was to consider the current knowledge of CyHV3 transmission factors and discuss the potential for recurring epidemic-level mortality events in carp found in Australia. Case studies were presented comparing KHVD outbreaks in wild carp in Japan and Epizootic haematopoietic necrosis virus (EHNV) outbreaks in pest redfin perch ( Perca fluviatilis L.) in Australia. The release of CyHV3 in thermally-favourable waterways in Australia would undoubtedly cause one high mortality KHVD epidemic. However, there is little evidence to suggest that repeated CyHV3 outbreaks would recur at a magnitude to counter the reproductive potential of the surviving carp.

ABSTRACT Urban freshwater wetlands have been identified as a potential source of mosquitoes of pest and public health concern in Australia. Mosquitoes most commonly associated with these habitats include Anopheles annulipes , Culex annulirostris , Culex quinquefasciatus , Coquillettidia linealis and Mansonia uniformis . However, adaptive management of freshwater wetlands for wildlife conservation or vegetation management can alter the local environmental conditions and may provide opportunities for other mosquito species to exploit these habitats. A series of small wetlands at Sydney Olympic Park, NSW, were drained in spring 2016 and allowed to refill via rainfall to improve conditions for the endangered green and golden bell frog Litoria aurea . Below-average rainfall was experienced that summer and the wetlands did not fully refill until early autumn. Surprisingly, immature stages of the estuarine mosquito, Aedes vigilax , were observed in the freshwater wetlands in exceptional abundances during this period. Adjacent to these freshwater wetlands there are extensive saltmarsh and mangrove habitats where highly abundant populations of Ae. vigilax are common. Observations of use of freshwater habitats by this estuarine mosquito have implications for urban freshwater wetland management and rehabilitation strategies, which currently do not consider the potential pest and public health issues associated with estuarine mosquitoes.

ABSTRACT The potent defensive chemicals of cane toads ( Rhinella marina ) protect them against predators that lack coevolved physiological tolerance to those toxins. That relative invulnerability may explain why major injuries (such as limb loss) appear to be rare in cane toads from most of their global range; however, we noted frequent predator-induced injuries (>4% of adults) in samples from within the toad’s native range (in French Guiana) and from a site (Lake Argyle) in north-western Australia. Toads at Lake Argyle enter the edge of the lake at night to rehydrate, exposing them to foraging freshwater crocodiles ( Crocodylus johnstoni ). Crocodiles rarely consume toads, but the attacks often result in loss of a limb. Because limbs contain relatively little toxin, attacks to the limbs expose a crocodile to nauseating but non-lethal amounts of toxin; and hence, facilitate taste aversion learning by the predator. The context of the encounters, such as differences in geography, may help to explain why the invasion of cane toads has not significantly impacted on crocodile populations at this site, in contrast to heavy impacts reported from nearby riverine systems.

ABSTRACT Technologies for remotely observing animal movements have advanced rapidly in the past decade. In recent years, Australia has invested in an Integrated Marine Ocean Tracking (IMOS) system, a land ecosystem observatory (TERN), and an Australian Acoustic Observatory (A2O), but has not established movement tracking systems for individual terrestrial animals across land and along coastlines. Here, we make the case that the Motus Wildlife Tracking System, an open-source, rapidly expanding cooperative automated radio-tracking global network (Motus, https://motus.org ) provides an unprecedented opportunity to build an affordable and proven infrastructure that will boost wildlife biology research and connect Australian researchers domestically and with international wildlife research. We briefly describe the system conceptually and technologically, then present the unique strengths of Motus, how Motus can complement and expand existing and emerging animal tracking systems, and how the Motus framework provides a much-needed central repository and impetus for archiving and sharing animal telemetry data. We propose ways to overcome the unique challenges posed by Australia’s ecological attributes and the size of its scientific community. Open source, inherently cooperative and flexible, Motus provides a unique opportunity to leverage individual research effort into a larger collaborative achievement, thereby expanding the scale and scope of individual projects, while maximising the outcomes of scant research and conservation funding.

The endangered Booroolong Frog Litoria booroolongensis has undergone dramatic declines over the majority of its range, which have largely been attributed to extensive clearing and ongoing modification associated with agricultural practices, disease and introduced pests. This paper presents a small-scale assessment of the distribution and habitat associations of the Booroolong Frog, using data collected during surveys for environmental impact assessments, in areas of likely preferred habitat identified along the Campbells and Macquarie Rivers south of Bathurst and the Turon River at Sofala New South Wales. Seven stream reaches were sampled within study areas, and the Boorolong Frog was recorded in four of those. Thirty-four Booroolong Frogs were recorded, by direct observation and call play back, usually in habitat typically associated with the species. Seven of these were found in highly degraded habitat reinforcing similar observations for this species in the literature. Field data collected during this study and the resulting habitat information will add to the knowledge of the distribution and habitat preferences of this threatened species. This study also provides recommendations to assist in the development of appropriate conservation management actions within the area.

Gambusia holbrooki, the “Mosquito Fish” introduced to Australian waterways from North America to control mosquito larvae, is widely distributed and abundant in both disturbed and undisturbed aquatic environments. Because it has become established in areas where Litoria aurea was once abundant, there is some suspicion that G. holbrooki's non-specific predatory behaviour may be instrumental in the decline of L. aurea . Laboratory and field experiments were conducted to assess the impact of G. holbrooki predation on L. aurea tadpole survivorship. Laboratory trials involved placing 30 L. aurea tadpoles per 46-litre aquarium in each of the following four treatments: control treatments (two aquaria with just tadpoles and two aquaria with tadpoles and the pondweed, Egeria densa ) and two predator treatments (two aquaria with fish and tadpoles and two aquaria with tadpoles, fish and pondweed). A daily census of the tadpoles was taken over four days. Based on ANOVA of six aquaria for each treatment, G. holbrooki significantly reduced L. aurea survivorship, but pondweed had no significant effect until the final census. The same experimental procedures were used for L. dentata . Again, tadpole number was significantly lower in aquaria housing G. holbrooki than in those without these fish, and pondweed influenced L. dentata's survival only on the final 72-hour census. Field experiments were conducted by placing 30 L. aurea tadpoles in 1.5 x 0.6 x 0.6 m screened cages which permitted water-flow but excluded predatory fish. A pair of cages (one with six G. holbrooki and one without) were placed in three separate ponds on two occasions. A daily tadpole census taken over four days revealed that tadpoles exposed to G. holbrooki had significantly higher daily mortality than tadpoles which were caged alone. These results show conclusively that G. holbrooki is a predator of L. aurea and L. dentata tadpoles. Future management decisions regarding L. aurea populations should include a consideration of G. holbrooki's impact as well as methods for their removal from breeding sites.

The Plague Minnow Gambusia holbrooki (Girard, 1859) was first introduced into Australian waters in 1925. Early introductions were carried out in Sydney, Melbourne, Brisbane, and later Perth, by government agencies in an attempt to reduce the incidence of mosquitoes in the capital cities. G. holbrooki flourished, but no reports were made of any apparent ecological problems arising from its introduction. World War II and the advent of the war in the Pacific resulted in heavy Allied troop movements between mainland Australia, New Guinea and the Pacific Islands. Malaria began to take a heavy toll, so the US Army instigated a means of mosquito control through the captive-breeding and introduction of the Western Gambusia G. affinis (Baird and Girard, 1853) throughout the south-west Pacific region. The Australian Army initiated a similar campaign using the already-available G. holbrooki to establish gambusia in creeks and wetlands near military bases and hospitals in eastern Australia. The Australian Army Malaria Unit was deployed to develop gambusia breeding ponds and to disperse the fish to suitable sites. Other methods of mosquito control were also employed. By the end of WW II G. holbrooki was widely established throughout many parts of eastern Australia,but the program of captive breeding and release remained in place for several more years as many malaria-affected personnel were now resident in Australia. In the early 1960s the first reports of adverse environmental impacts of gambusia on native fish populations appeared, and these were quickly followed by reports of impacts on other organisms, such as frogs. Gambusia was always likely to become an environmental pest species once introduced into Australia. The need to control mosquitoes and mosquito-borne diseases during and following WW II was paramount, however, and efforts to do this greatly accelerated the spread of gambusia. The fish established in high densities in areas where undesirable environmental consequences later became apparent, precipitating the disaster for wildlife that we see today.

Gambusia holbrooki is a small, aggressive fish introduced into Australia in 1925 to control mosquitoes. It has been suggested that this species may also prey on tadpoles and be a contributing factor in the decline of some Australian frog populations. We examined the influence of tadpole body size (10 mm. 15 mm and 20 mm). predator prey ratio (1 : 1, 1 :2 and 1 :4) and nutritional status of the predator on the level of predation by G. holbrooki on tadpoles of Limnodynasfas peronii . Unfed fish attacked all three size classes of tadpoles without any significant preference but did so more vigorously when the predator/prey ratio was densest. Predator/prey ratio had no significant overall effect on attack of tadpoles by fed fish but there was a preference for the smaller tadpoles during the first six hours of the experiment. Unfed fish also consumed more of the tadpoles they attacked than did the fed fish. Field surveys were carried out on 10 permanent water bodies in north-west Sydney to examine any correlation between the abundance of G. holbrooki and frog species richness or abundance. The most abundant species was C. signifera . Regression analysis showed a negative relationship between density of G. holbrooki and the abundance of frogs. A positive relationship between the abundance of tree frog species and the cover of aquatic vegetation was also found. While this study did not investigate other factors contributing to declining frog populations, the results of the laboratory experiments and field surveys are consistent with the hypothesis that G. hoibrooki is contributing to declining frog populations.

ABSTRACT The invasive Red-eared Slider Trachemys scripta elegans has spread extensively, forming naturalised populations on all continents except Antarctica. Ranked among the 100 worst invasive species, there are biosecurity concerns that native turtles become outcompeted and displaced, as well as other speculative impacts. The actual ecological impacts in Australia have not been properly studied, however impacts shown in other countries are concerning. Incursions have presented in New South Wales, Queensland, Victoria, Western Australia and the Australian Capital Territory. A number of sightings have been reported from southern Sydney, including six sites where more than one slider has persisted. The incursions at Yeramba Lagoon in the Georges River National Park and the Centennial Parklands have been the most documented, whereas incursions in the Lime Kiln Bay Wetland, Rockdale Wetlands Corridor and Audley in the Royal National Park appear to have occurred recently. To date, breeding in southern Sydney has only been confirmed at Yeramba Lagoon. A range of removal techniques have been successfully applied to eradicate isolated incursions in Brisbane and Melbourne. However, these options are difficult to implement in southern Sydney sites where incursions occur in high visitation public lands.

I investigated whether exotic turtle species were capable of establishing breeding populations in the Sydney area and confirmed that two exotic species were present: Trachemys scripta elegans and Clemmys marmorata . Mature females of both species were recorded with shelled eggs in the oviducts and evidence of nesting by T. s. elegans species was noted. Trachemys scripta elegans were observed in a range of sizes which suggested that it has established a foothold, at least in southern Sydney. Competition from this exotic species could have a detrimental impact on the local species, Chelodina longicollis and Emydura macquarii dharuk .

This paper examines the distribution, habitat and conservation status of five species of the freshwater crayfish genus Euastacus from eastern Australia: E. dalagarbe, E. girurmulayn, E. guruhgi, E. jagabar and E . mirangudjin . Although the five species have discrete distributions, they have similar habitat requirements, occurring only at highland (310-960 m) sites in the Central Eastern Rainforest Reserves of Australia. They all occur in minor or peripheral habitats (i.e. small tributaries, damp gullies and wet soaks) and are sympatric with the much larger species, E. sulcatus . On the basis of their restricted ranges, E . girurmulayn, E. guruhgi, E. jagabar and E. mirangudjin satisfy the IUCN criteria for listing as ‘Vulnerable’ (VU D2). Euastacus dalagarbe is close to qualifying for listing as vulnerable, and can be considered as ‘Near Threatened’. Potential threats for these species are discussed.

Riparian zones are an important habitat for a range of bat species and, as a consequence, understanding whether land use practices such as timber harvesting influence their use is important for conservation and management. This small-scale study used bat activity as a measure of the use of riparian and up-slope zones along headwater streams by bats, and to determine whether past timber harvesting influenced the use of these areas by bats by comparing regrowth with no retained riparian buffers and mature forest. This study found no significant differences in bat activity between treatments, but did find a trend of higher bat activity in riparian zones compared to up-slope zones, particularly in regrowth forest. However, many sites had little to no bat activity indicating activity was influenced by factors not measured in this study. Despite limited data, this study highlights the potential value of retaining riparian habitat in harvested forests for bats, as is practised elsewhere in Australia, and the need for future research into the effectiveness of forest retention measures for wildlife.