Abstract In early 2003 a series of large, wildfire‐related sediment slugs occurred in streams the south‐eastern Australian alpine region. Back‐pack and boat‐mounted electrofishing were used to measure changes riverine fish fauna after one particularly large slug which started an upland stream then travelled downstream through 200 km third fourth order stream. Twelve impact sites eight control surveyed where there previous data on populations. The directly had passed 12, 24 36 months after....

Abstract – This study of Murray cod ( Maccullochella peelii ) movements in a large lowland river south‐eastern Australia indicated that the species was not sedentary, but undertook complex followed seasonal pattern. While there were sedentary periods with limited home ranges and high site fidelity, also under took larger for considerable portions year coinciding its spawning schedule. generally comprised (up to 130 km) from location late winter early spring new upstream position, by rapid...

A 2 year (2000–2001) radio‐tagging study was undertaken to investigate the movements of 51 golden perch Macquaria ambigua in Murray River at Nyah north‐western Victoria, Australia. During winter both years, did not undertake >5 km and displayed strong home range fidelity. In first there an increase distance movement during late spring which coincided with increasing water temperature river discharge. Nineteen were tracked this period, 10 travelled downstream between 11 290 km. Seven these...

Otolith chemical analyses (proton‐induced X‐ray emission and laser ablation inductively coupled plasma mass spectrometry) were used to examine patterns of diadromy in Australian grayling Prototroctes maraena collected from three rivers south‐eastern Australia. Concentrations Sr:Ca Ba:Ca measured the sagittal otoliths 25 fish water samples on two occasions multiple sites within freshwater, estuarine marine reaches rivers. The results provide evidence residency during juvenile phase, with high...

Abstract Movement through streams is critical for the maintenance of diadromous fish populations. Numerous passage improvement techniques exist, and knowledge their effectiveness required to conserve target species. An existing 70‐m pipe culvert was considered a barrier success young‐of‐year (YOY) Galaxias spp. as result high water velocity (0.9 m/s). Water in reduced by installing concrete weir downstream culvert. A lateral ridge rock‐ramp fishway installed provide over weir, baffles were...

Abstract Monitoring fish movement can test the effectiveness of environmental flow releases when they are used to trigger spawning behaviour. Environmental have been enhance Australian grayling ( Prototroctes maraena ) in regulated rivers south‐eastern Australia and resource managers require knowledge on conservation this threatened species. was monitored Thomson River, using acoustic telemetry determine whether species undergoes a migration, where migrate timing relation releases. Drift...

Abstract The construction of fishways for upstream and downstream connectivity is the preferred mitigation measure hydropower dams other riverine barriers. Yet empirical evidence effective design criteria many species missing. We therefore assembled a group international fishway designers combined their knowledge with available data using formal expert elicitation protocol Bayesian networks. method we use minimizes biases typically associated such approaches. Demonstrating our application...

Abstract – This article reports on the findings of a study undertaken within Murray‐Darling River Basin in southeastern Australia, which investigated impact weirs downstream fish movement. Downstream movement was monitored at Kennedy's Weir (an overshot, 2 m high weir) Broken Creek and Torrumbarry undershot, 6.5 Murray River. A trap used to sample indicated that travelled over this weir without sustaining injury or death. follow‐up study, whereby were captured below two respective...

Summary The Australian irrigation industry diverts significant volumes of water from our rivers, and as such, may also divert entrain riverine fish. Although it is widely acknowledged that native fish fauna have been greatly affected by a variety anthropogenic changes, little known about the extent or significance entrainment in systems. This paper presents results preliminary investigation into diversion channels undertaken Goulburn‐Murray Irrigation Network, Victoria, Australia. case study...

The gametogenic cycle of three size classes the freshwater mussel Dreissena polymorpha was investigated by histological examination during 2000 and 2001 at Lough Derg. Co. Limerick, Ireland. This study provided a full staging method for reproductive zebra mussel. Gonads gamete development were observed in mussels all months sizes from 6.0 mm up to 25.9 long. (non ripe) only small percentage (3.4%) individuals smaller than females. Thus, become sexually mature are able reproduce least long...

Population genetic variation of Australian grayling Prototroctes maraena was examined to determine whether the dispersal strategy this amphidromous species favours retention larvae and juveniles in close proximity their natal river, or mixing populations via marine dispersal. Variation microsatellite mitochondrial DNA markers unstructured differentiation indistinguishable from zero across four coastal rivers spanning approximately one-quarter continental range species. This result indicates...

Radio tagging and tracking are widely used to study freshwater fish; however, details of fish survival or tag retention rates rarely reported. The results from five independent trials associated with different attachment methods reported in the present study. Implanted peritoneal cavity tags were trialled for two native Australia species (golden perch silver perch) introduced carp. Oesophageal external also on perch. implantation golden perch, carp achieved an overall success rate 81% (after...

A portable light-trap was designed and constructed to assist in Museum taxonomic studies on Crustacea. The trap throughout of transparent Perspex. light-source a chemoluminescent ampoule marketed under the name Cyalume® Lightstick. present offers several advantages. It is inexpensive construct, sturdy, readily portable, easy operate, safe use. Field trials Lough Hyne (Ine), Co. Cork, south west Ireland, have proved apparatus be most successful attracting wide variety crustaceans.

Abstract Anguillid eel populations have declined dramatically over the last 50 years in many regions of world, and numerous species are now under threat. A critical life-history phase is migration from freshwater to distant oceans, culminating a single life-time spawning event. For anguillids, especially those southern hemisphere, mystery still shrouds their oceanic migrations. We investigated migrations Australasian short-finned ( Anguilla australis ) using pop-up satellite archival tags....

SummaryThe spawning status of a population G. bispinosus from Buffalo Creek in north-eastern Victoria was monitored over two consecutive seasons. Spawning occurred December both years and coincided with increasing water temperature. Eggs were found deposited artificial tubes placed the creek stream substrate, under small, generally flat, boulders, confirming previous authors’ assumptions. The implications this reproductive strategy include susceptibility species to increased sedimentation...

Summary Environmental rehabilitation budgets are often limited, and management actions need to be prioritised achieve the best outcomes. Prioritisation can done when evidence informs decision‐making process. We acoustically tagged twenty Golden Perch ( M acquaria ambigua ) in Loddon River, Australia, tracked their movements gain an understanding on requirements for fish passage at a major regulating structure, Box Creek regulator. The of these were monitored through network receivers located...

River regulation has degraded aquatic biodiversity globally, and the effects can be pronounced for diadromous species, whose life history processes depend on flow conditions, such as cues adult migration, spawning, attracting recruits into coastal rivers promoting upstream dispersal. Environmental flows are being used to mitigate of river regulation, understanding their effectiveness is required improve management practices. This study examined targeted environmental dispersal three...

Abstract Anthropogenic alterations to river flow regimes threaten freshwater biodiversity globally, with potentially disproportionate impacts on species that rely cues trigger critical life history processes, such as migration for diadromous fishes. This study investigates the influence of discharge abundance juvenile fish moving into rivers by four temperate catadromous or amphidromous (common galaxias Galaxias maculatus , spotted truttaceus climbing brevipinnis and threatened Australian...

Abstract – A 2‐year study of the threatened Australian grayling, Prototroctes mareana, was undertaken to investigate its reproductive strategy in relation river flow. Monitoring maturity Barwon River south‐eastern Australia indicated that no spawning occurred 2 years. In both years, ovarian involution observed a large proportion sampled population; flows during this period were less than historical average. When coupled with evidence, these observations suggest coincides increased discharge....

Outcomes from restoration and reintroduction programs can be enhanced by understanding the habitat use of animals, how likely they are to move why? River blackfish native southeastern Australia where their range abundance have declined. We reintroduced 27 river into two sites, one rehabilitation had been undertaken (with more vegetation, instream woody habitat, undercut banks) an unmanipulated control site. monitored fish for 9 months after release assess site occupancy, use, drivers...

Successful monitoring of fish eggs or larvae facilitates the assessment management actions (e.g. environmental flow releases) on spawning success. Paired sets drift nets (one at surface and one bottom) were used six sites in Thomson River to determine whether we can improve our ability monitor success Australian grayling, Prototroctes maraena. Over 900 P. maraena captured, with 90% being captured set bottom. All but two sites, which had faster rates a substrate small gravel rather than fine...

Abstract Anguillid eel populations are under threat globally. A particularly vulnerable life‐cycle stage is the migration of mature adult eels downstream from freshwater habitats through estuaries into sea to spawn. This study investigated factors associated with short‐finned Anguilla australis (Richardson 1841) a coastal wetland (Lake Condah) in south‐east Australia, using acoustic telemetry. Migration was time year, higher water level and river flows, decreasing temperature, darker moon...