ORCID Profile
0000-0001-8808-4998
Current Organisation
NSW Department of Primary Industries
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Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/PC19023
Abstract: Safety considerations for researchers shape ecological research approaches in dangerous aquatic environments. A series of recent studies has demonstrated that the moray Gymnothorax polyuranodon (Family Muraenidae) occupies freshwater in the adult phase. However, its potential use of tidal habitat remains largely unexplored, due partly to the challenges of performing underwater research within estuarine crocodile territories. In September 2017, opportunistic snorkel-based observations revealed in iduals of this species occupying lairs at an upper tidal creek site during low tide (under freshwater conditions). This provided an opportunity to tailor field-based measurements of the salinity tolerance of this species a fortnight later during a more substantial high tide. Specifically, remote underwater video, snorkel and above-water observations of morays, combined with salinity measurements, reveal that G. polyuranodon is capable of tolerating salinity of at least 14.4 for several hours and can inhabit salinity of 19 for a period of several minutes. This finding, when viewed in synergy with other relevant studies of G. polyuranodon, indicates that the species is either catadromous or hidromous or capable of either strategy.
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/PC19020
Abstract: Field-based video recording of courtship between a male and female Stiphodon semoni (Family Gobiidae), afforded the opportunity to discern specific behaviours not reported of sicydiine gobies previously, including tail-wagging and kiss-like behaviour by the male. Furthermore, a subset of behaviours that resemble those from published reports of other sicydiines in courtship and a subset of behaviours that are analogous to those exhibited by guppies (Poecilia reticulata, Family Poeciliidae) are reported and discussed briefly and used to contend that sicydiines are ripe for detailed study of sexual signalling behaviour in fishes.
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/PC19053
Abstract: Globally, freshwater fishes are declining at an alarming rate. Despite much evidence of catastrophic declines, few Australian species are listed as threatened under national legislation. We aim to help redress this by identifying the Australian freshwater fishes that are in the most immediate risk of extinction. For 22 freshwater fishes (identified as highly threatened by experts), we used structured expert elicitation to estimate the probability of extinction in the next ~20 years, and to identify key threats and priority management needs. All but one of the 22 species are small (& mm total length), 12 have been formally described only in the last decade, with seven awaiting description. Over 90% of these species were assessed to have a & % probability of extinction in the next ~20 years. Collectively, the biggest factor contributing to the likelihood of extinction of the freshwater fishes considered is that they occur in small (distributions ≤44km2), geographically isolated populations, and are threatened by a mix of processes (particularly alien fishes and climate change). Nineteen of these species are unlisted on national legislation, so legislative drivers for recovery actions are largely absent. Research has provided strong direction on how to manage ~35% of known threats to the species considered, and, of these, ~36% of threats have some management underway (although virtually none are at the stage where intervention is no longer required). Increased resourcing, management intervention and social attitudinal change is urgently needed to avert the impending extinction of Australia’s most imperilled freshwater fishes.
Publisher: Wiley
Date: 25-05-2022
DOI: 10.1002/ECY.3682
Publisher: Wiley
Date: 26-07-2019
DOI: 10.1111/JFB.14090
Abstract: Juvenile silver grunter Mesopristes argenteus were observed, photographed and filmed manoeuvring objects with their snout and nape to expose benthic prey in two short steep coastal streams, including in the micro-estuary of one of these streams within the Australian Wet Tropics. Objects that were moved included leaves, sticks, bark, wood, seed pods, rainforest fruit, coral fragments and pebbles. Follower fish were sometimes associated with the foraging behaviour.
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/PC19019
Abstract: S ling fish communities in tropical estuaries is inherently challenging due to poor visibility and the potential presence of dangerous fauna. We present two strategies for improving the identification of fishes in a turbid tropical estuary using video. The first was to attract species close to the camera by using two different bait types compared with no bait, and the second involved manipulating footage in the postfilming phase. No significant difference was found in the species richness recorded among camera bait treatments (thawed Australian sardines, canned sardines and unbaited), although baited cameras did detect 13 taxa not observed on the unbaited cameras. Three different image restoration algorithms (histogram equalisation, white balance and contrast-limited adaptive histogram equalisation) were compared in processing 22 instances where fish could not be confidently identified to species or genus level. Of these processed clips, five were able to be identified to species level by a panel of four coauthors. Further, two of the three algorithms yielded higher average confidence values for identification at the order, family, genus and species level than when the unprocessed footage was viewed. Image restoration algorithms can partly compensate for a reduction in image quality resulting from turbidity, addressing a key challenge for video-based s ling in estuaries.
Publisher: Wiley
Date: 10-04-2021
DOI: 10.1111/FWB.13712
Abstract: Tropical short, steep coastal streams are typically dominated by diadromous species, especially hidromous fishes, crustaceans, and molluscs. We undertook a study to determine the distribution of fishes along the stream continuum and determine if substantial natural instream barriers influenced assemblage composition. We surveyed fish assemblages in three short, steep coastal streams in the Australian Wet Tropics by snorkelling and performing single pass counts in each 100‐m section along the entire main channel from the high‐tide mark to the source (or near source: until fish were no longer recorded). A primary focus was mapping the distribution and relative abundance of sicydiine gobies, and we also estimated freshwater crustacean numbers (Caridea: Palaemonidae and Atyidae). In total, 2,837 in idual fish of 25 species were recorded upstream of the high‐tide mark across the three streams and the first records of an additional sicydiine goby ( Smilosicyopus leprurus ) were obtained from continental Australia. Consistent with findings from tropical Pacific island streams, we observed a shift in fish assemblage composition along the elevation gradient and in relation to major instream barriers (e.g. waterfalls m, and high flow chutes across smooth bedrock surfaces). Species richness of diurnal predatory fishes was greatest in the lower course of streams and absent upstream of major instream barriers. Diurnal predatory fishes were, in some instances, found upstream of barriers. Specifically, large adult ( mm total length) Kuhlia rupestris (diurnal predators) accessed reaches above challenging sequences of cascades combined with small waterfalls. In contrast, all sizes of that species, adult Kuhlia marginata ( mm total length) and a ersity of other diurnal predatory fishes occupied the lower course of streams including upstream of gentle cascade sequences or isolated small waterfalls. Where abundances of diurnal predatory fishes were high, freshwater carideans were rarely observed. Peak densities of carideans were observed upstream of major barriers, with moderate densities in the upper mid‐course in the presence of few Kuhlia spp. The current study demonstrates the value of complete single‐pass surveys of fish assemblages in tropical short, steep coastal streams by revealing the highly localised occupation of particular reaches by rare fishes. It also points towards the importance of stream‐specific characteristics, namely the position of waterfalls in dictating diadromous predator distribution with consequences for community structure, thereby aligning with the Riverine Discontinuum Concept.
Publisher: Wiley
Date: 19-09-2021
DOI: 10.1111/JFB.14895
Abstract: Gambusia holbrooki is one of the world's most environmentally damaging introduced species, being notoriously difficult to control once established. A composite double‐winged fyke net comprising four vertically stacked compartments was developed to determine the potential to control G. holbrooki , while reducing negative interactions of this aggressive species with small threatened fishes. The stacked fyke net captured three times as many G. holbrooki as a conventional fyke net while maintaining consistent catches of native fishes relative to that from a conventional fyke net, and detected species‐specific vertical distributions. This stratified net design represents a valuable management option for controlling this agonistic species or for limiting antagonistic interactions between G. holbrooki and native species during typical fyke s ling of native ecosystems.
Publisher: Wiley
Date: 12-02-2023
DOI: 10.1111/EFF.12698
Abstract: Freshwater ecosystems are both incredibly bio erse and highly threatened globally. Variation in environmental parameters including habitat and flow can substantially affect many ecological processes within riverine aquatic communities, but the ties between such parameters and ecology are neither well studied nor understood. In highly variable tropical dryland river systems, assessing such relationships requires data collection over inter‐decadal time scales, which is not typically permitted on development schedules driven over short periods (including election and funding cycles). Here, we used seine net s ling data collected over an 18‐year period in the tropical dryland Fitzroy River, Western Australia, to assess how environmental and temporal factors including habitat, seasonality, and inter‐annual variation in wet season magnitude affect the community assemblage structure, recruitment, and growth of aquatic species in dryland rivers. Results demonstrated that macrohabitat (main channel vs floodplain creek) and the magnitude of wet season rains and resultant flooding both had a substantial influence on biotic communities, alongside seasonal and diel variation. The magnitude of wet season flooding (measured as river discharge volume) had the greatest impact on assemblage composition within floodplain creek habitats and was a significant driver of recruitment rates and growth of recruits and adults of several species examined. This study highlights key considerations for conserving dryland river systems and constituent biota. Specifically, these are maintaining (a) rhythmicity of flow within each year, (b) ersity of flow volume between years, and (c) a variety of habitat types including ephemeral, semi‐permanent, and permanent shallow floodplain and deeper main channel pools, in order to support a erse array of generalist and specialist diadromous and potamodromous fishes.
No related grants have been discovered for Brendan Ebner.