Ivor Stuart

• Charles Sturt University, Albury

Context There is a global problem with ongoing riverine infrastructure projects where, despite knowledge of potential environmental impacts, there is rapid development, often without appropriate environmental safeguards. This results in fragmentation of riverine fish communities, especially diadromous species. Understanding freshwater fish larval e...

Fish biodiversity assessments are vital for understanding threats and aquatic ecosystem health. In the Poso River, Central Sulawesi, changes in biodiversity are influenced by habitat alteration, non-native species, and overfishing. This study evaluates fish and crustacean biodiversity in the Poso River system to address these challenges for improvi...

A fishway is an engineered structure designed to help fish navigate past artificial barriers in rivers such as dams, weirs and regulators. An effective fishway design requires an understanding of fish biodiversity and migration requirements of the local community. To support the conceptual design of a fishway at Caringin Weir in the Cibareno River...

Ecosystems worldwide are increasingly being invaded by multiple species, and the rate of biological invasion is accelerating, leading to more interactions among invasive species. One such interaction that has received little attention is the phenomenon of ‘serial replacement’ or ‘over-invasion’, where an established invasive species is supplanted b...

Ecosystems worldwide are increasingly being invaded by multiple species, and the rate of biological invasion is accelerating, leading to more interactions among invasive species. One such interaction that has received little attention is the phenomenon of ‘serial replacement’ or ‘over-invasion’, where an established invasive species is supplanted b...

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 the sea to spawn. This study investigated the factors associated with downstream migration of the short‐finned eel Anguilla australis (Richardson 1841) from...

Common carp (Cyprinus carpio; hereafter carp) is a highly invasive freshwater fish that has colonised river basins across the world causing ecological degradation. In regulated rivers, restoration of natural flow regimes to rehabilitate aquatic ecosystems is a primary focus of environmental management, yet some actions (e.g., environmental water de...

Many fish rely on being able to move between rivers and floodplains to fulfil key life history events, but river regulation has reduced floodplain inundation compromising these connections and causing the loss of ecosystem function more generally. Managed inundations are being trialled in some systems as a solution, whereby engineered floods using...

Models based on ecological processes (process‐explicit models) are often used to predict ecosystem responses to environmental changes or management scenarios. However, models are imperfect and need to be validated, ideally by testing their assumptions and outputs against independent empirical data sets. Examples of validation of process‐explicit mo...

Freshwater ecosystems are under extreme stress due to anthropogenic influences including changing climate, river regulation and water abstraction. Improving our understanding of the hydrological determinants of key life‐history processes of fish, as well as the spatial scales over which these processes occur, is fundamental to inform effective reco...

Common carp ( Cyprinus carpio ; hereafter carp) is a highly invasive freshwater fish that has colonised river basins across the world causing ecological degradation. In regulated rivers, restoration of natural flow regimes to rehabilitate aquatic ecosystems is a primary focus of environmental management, yet some actions (e.g., environmental water...

The common carp (Cyprinus carpio) is a non-native fish species in many parts of the world which has negative impacts on freshwater environments including plant loss, re-suspended sediment, and altered nutrient flux. Eradication of common carp can be extremely difficult and conventional management efforts have focused on control or containment, achi...

The construction of dams and weirs has fragmented many rivers and streams globally, and this is a major threat to biodiversity. The most common method used to reduce these impacts is to construct fishways. Published examples show that while fishways can be effective, their performance can also be highly variable. Given this variability, it is criti...

Anguillid eel populations have declined dramatically over the last 50 years in many regions of the world, and numerous species are now under threat. A critical life-history phase is migration from freshwater to distant oceans, culminating in a single life-time spawning event. For many anguillids, especially those in the southern hemisphere, mystery...

Large dryland and semi-arid rivers are among the world’s most heavily modified ecosystems, and the Darling–Baaka River of eastern Australia highlights the challenges in conserving such ecosystems. Since 2000, the hydrology at the downstream end of the system (the Lower Darling River, LDR) has been transformed from a naturally near-perennial flowing...

Anguillid eel populations have declined dramatically over the last 50 years in many regions of the world, and numerous species are now under threat. A critical life-history phase is migration from freshwater to distant oceans, culminating in a single life-time spawning event. For many anguillids, especially those in the southern hemisphere, mystery...

Anthropogenic alterations to river flow regimes threaten freshwater biodiversity globally, with potentially disproportionate impacts on species that rely on flow cues to trigger critical life history processes, such as migration for diadromous fishes. This study investigates the influence of river discharge on the abundance of juvenile fish moving...

Common carp (Cyprinus carpio) are one of the world's most destructive vertebrate pests. In Australia, they dominate many aquatic ecosystems causing a severe threat to aquatic plants, invertebrates, water quality, native fish and social amenity. The Australian Government is considering release of cyprinid herpesvirus-3 (CyHV-3) as a control measure...

River regulation has degraded aquatic biodiversity globally, and the effects can be pronounced for diadromous species, whose life history processes can depend on flow conditions, such as cues for adult migration, spawning, attracting recruits into coastal rivers and promoting upstream dispersal. Environmental flows are being used to mitigate the ef...

In riverine ecosystems, movements of biota among different parts of the river network are fundamental to the functioning and sustainability of populations, especially for fish. Globally, human activities (e.g., dam construction and altered flow regimes) have impaired riverine fish movements through reduced river connectivity, leading to well-docume...

Many freshwater fishes are imperilled globally, and there is a need for easily accessible, contemporary ecological knowledge to guide management. This compendium contains knowledge collated from over 600 publications and 27 expert workshops to support the restoration of 9 priority native freshwater fish species, representative of the range of life-...

The Murray–Darling Basin (MDB) is Australia’s food bowl, contributing 40% of agricultural production and supporting a population of over 4 million people. Historically, the MDB supported a unique native fish community with significant cultural, subsistence, recreational, commercial and ecological values. Approximately one-quarter of the MDB’s nativ...

Recognition that many species share key life-history strategies has enabled predictions of responses to habitat degradation or rehabilitation by these species groups. While such responses have been well documented for freshwater fish that exhibit ‘periodic’ and ‘opportunistic’ life-history strategies, this is rare for ‘equilibrium’ life-history, du...

• Pelagic spawning riverine fish (pelagophils) spawn in free‐flowing river habitats with downstream drift of eggs and larvae but the spatial scale is often unknown, and this constitutes a major ecological knowledge gap. • In the arid Darling River in south‐eastern Australia, the present objectives were: (i) to determine the potential downstream dis...

Fisheries in many tropical river-floodplain systems are under threat from physical obstructions caused by ongoing river infrastructure development. There is a growing need for innovative, cost-effective technologies to mitigate the impacts of these obstructions. This study examined the effectiveness of a new cone fishway for facilitating lateral mi...

Multi‐strain, host‐disease dynamics describe a system where multiple strains of a pathogen compete for susceptible individuals of a single host. The theoretical properties of these systems have been well studied, but there are few empirical studies in wildlife hosts. We examined the impacts of two novel strains of rabbit haemorrhagic disease virus...

Combined fishway-culvert facilities are common in many tropical river systems in South East Asia, but little is known regarding their mutual passage effectiveness. We investigated the lateral passage of Lower Mekong Basin fish in Lao PDR, through a combined cone fishway-sluice gate culvert facility between the Mekong River and an adjacent wetland....

In tropical coastal lowland rivers, there are frequently biodiverse upstream migrations of post-larval and juvenile diadromous fish from estuaries into freshwater. Tidal barriers completely block major migratory pathways for these fish and have contributed to major losses of freshwater biodiversity. In northern Australia, early efforts to improve t...

Worldwide, riverine fish are the target of environmental water because populations have declined in lotic river habitats following river regulation. Murray cod is an endangered Australian riverine fish with remaining populations associated with lotic river reaches with instream habitat, including some creeks operated as part of irrigation systems....

Fishways are being provided more regularly than ever before and new designs are needed to provide passage for whole fish communities. Despite recent progress, fishways have frequently performed poorly, especially for small-bodied fish (i.e. 10–100 mm long), which can form large aggregations below stream barriers. This was the genesis for the develo...

Understanding the influence of extrinsic factors such as hydrology and hydraulics on recruitment provides essential insight to inform management of fish populations. The critically endangered silver perch Bidyanus bidyanus is a long-lived, potamodromous pelagophil endemic to Australia’s Murray–Darling Basin. Declines of this species are often attri...

1. Invasive mammalian predators commonly coexist with invasive mammalian herbivore prey. Managers often advocate controlling invasive prey in the belief that this will also reduce invasive predator abundance. Such an outcome would have desirable ecological and financial benefits, but there have been few tests of this hypothesis. 2. We used large-sc...

Common carp, Cyprinus carpio, are a major pest fish in Australia, North America, New Zealand and parts of Europe. The Williams’ carp separation cage was developed to separate carp from native fish as they passed through fishways by exploiting their strong migratory and unique jumping behaviour. We report on an 11‐year commercial application of the...

River infrastructure poses a serious threat to diverse and productive fish stocks in many tropical river-floodplain systems; particularly the Lower Mekong River, where the fisheries are vital for food security. Dams and weirs block fish migration pathways and prevent access to feeding, spawning or nursery habitat. Fishways are becoming increasingly...

Environmental water managers must make best use of allocations, and adaptive management is one means of improving effectiveness of environmental water delivery. Adaptive management relies on generation of new knowledge from monitoring and evaluation, but it is often difficult to make clear inferences from available monitoring data. Alternative appr...

Carp are a highly successful invasive fish species, now widespread, abundant and considered a pest in south-eastern Australia. To date, most management effort has been directed at reducing abundances of adult fish, with little consideration of population growth through reproduction. Environmental water allocations are now an important option for th...

The construction of fishways for upstream and downstream connectivity is seen as the preferred mitigation measure for hydropower dams and other riverine barriers. Yet empirical evidence for effective design criteria for many species is not available. We therefore assembled a group of international fishway design experts and combined their knowledge...

The Fish Friendly Fitzroy: Bypassing the Barrage project was initiated to improve fish passage in the lower Fitzroy Basin and restore fish communities in the lower 150 km of stream habitat. The major specific objective was to evaluate the success of an innovative new cone fishway technology as well as remediate the existing vertical slot fishway to...

Movement through streams is critical for the maintenance of diadromous fish populations. Numerous fish passage improvement techniques exist, and knowledge of their effectiveness is required to conserve target species. An existing 70-m pipe culvert was considered a barrier to the passage success of young-of-year (YOY) Galaxias spp. as a result of hi...

In wildlife shooting programs, the energy profile of the projectile or bullet (i.e., kinetic energy transferred to the animal), as distinct from caliber (projectile diameter), is an important factor for animal welfare. We examined the role of projectile energy in determining animal welfare outcomes for a typical European rabbit (Oryctolagus cunicul...

The objective of this project was to assess and identify all potential barriers to fish passage and lows flows in the Barwon and Moorabool River basins. This included natural barriers as well as artificial barriers that will affect fish passage and flow. Artificial barriers included but are were not limited to weirs, culvert crossings, ford crossin...

Environmental water managers must make best use of scarce water allocations, and adaptive management is one means of improving the effectiveness of environmental water delivery. We developed statistical models designed to inform adaptive management of the threatened Australian grayling (Prototroctes maraena) in the Thomson River, Victoria Australia...

The Fitzroy barrage vertical-slot fishway provided adequate functionality in the 1990s but new technology is now available to vastly increase its functionality. The objective of the present report was to experimentally determine the suitability of various new hydraulic control innovations, including sills and keyhole slots, to provide significantly...

Reforestation has been widely adopted as a solution to multiple global change issues. However, the role of herbivory by invasive species in the restoration of grassland to forest has received little attention. We conducted a field experiment to investigate the impacts of a widespread invasive mammalian herbivore, the European rabbit (Oryctolagus cu...

Construction of instream barriers, preventing fish from accessing spawning, nursery and feeding habitat, is a major issue impacting fisheries sustainability throughout the world. Since European settlement, development in the Murray-Darling Basin for irrigation and potable water supplies has led to the construction of over 10,000 barriers to fish mo...

Context Warren ripping has been demonstrated to be an effective tool for controlling rabbit populations. However, few studies have examined factors influencing the rate at which ripped warrens are likely to be recolonised (i.e. be re-opened). Aims To examine factors influencing the recolonisation of ripped warrens by rabbits by using data collecte...

Data used in our analyses of common carp population dynamics in six New South Wales rivers, 1984/85–2001/02 (Microsoft® Office Excel spreadsheet; OnlineResource2.xls)

Data used in our analyses of common carp population dynamics in the Murray-Darling Basin rivers, 1962/63–2001/02 (Microsoft® Office Excel spreadsheet; OnlineResource1.xls)

Fish passage through an experimental vertical-slot fishway was assessed at a floodplain regulator on the Mekong River in Central Laos between April and July 2009. Experiments were conducted to investigate the influence of fishway floor slope (1v:15h or 1v:7.5h) on fish passage success with a view to developing a series of optimal design criteria fo...

There is much interest in managing invasive freshwater fish, but little is known about the dynamics of these populations following establishment. We used annual commercial catch-per-unit-effort data at multiple spatio-temporal scales to test hypotheses about the population dynamics of invading common carp (Cyprinus carpio) in the Murray-Darling Bas...

To provide passage for migratory native fish, a series of 14 vertical-slot and lock fishways are being constructed on the Murray River in south-eastern Australia. Three of these vertical-slot fishways, at Locks 7, 9 and 10, have a conservative slope (1V : 32H) and are designed with internal hydraulics suitable for the passage of a broad size range...

Off-channel habitats, such as wetlands and backwaters, are important for the productivity of river systems and for many species of native fish. This study aimed to investigate the fish community, timing and cues that stimulated movement to and from off-channel habitats in the highly regulated Lake Hume to Lake Mulwala reach of the Murray River, sou...

A major environmental issue for hydro-electric power generation is passage of fish through turbines, or entrainment onto trash racks. At Yarrawonga Weir, on the upper Murray River in south-eastern Australia, the positioning of a fish lock resulted in the potential for upstream migrating fish to be swept back into the adjacent power station by cross...

Abstract –  Common carp (Cyprinus carpio L.) are a major freshwater invader and knowledge of their movements is important for planning control efforts. To investigate the movement patterns of common carp, radio-tags were implanted into 46 adult fish; 37 near a large floodplain wetland, the Barmah-Millewa forest, and 9 in the Murray River approximat...

Abstract  A modified ‘lock’ mode of operation was trialled within a low-slope (3.1%) vertical-slot fishway to improve passage of small-bodied (<60 mm long) native fishes in the Murray River, Australia. Significantly greater numbers of three small-bodied native fish and two crustacean species ascended the fishway during lock operation than during st...

Abstract – The links between river flows, water temperature, river regulation and recruitment variability of Golden Perch, Macquaria ambigua oriens, were investigated from the Fitzroy Basin, Queensland. The dominant age classes determined by interpreting growth marks observed in otoliths were variable among rivers. Positive correlations between the...

The diel variation in boat electrofishing catches was investigated on the lower Murray River (south-eastern Australia), downstream of three low-level weirs. Fish assemblage composition did not differ among three sites, but differed substantially between day and night. Significantly more small-bodied species (e.g. Australian smelt Retropinna semoni,...

Abstract  Loss of river-floodplain (lateral) connectivity has impacted on fish communities and fisheries around the world. However, evidence of the impacts of reduced lateral connectivity on Australian native fish remains scant. To document these impacts, isolated pools located immediately downstream of two major regulators (or weirs) that control...

Fishways are commonly used to restore native fish movements in regulated rivers. In the Murray-Darling Basin, Australia, 14 fishways are to be built by 2011 to improve passage along 2225 km of the river. The first of these fishways, constructed in 2003, is a vertical-slot design with low water velocities (0.98–1.4 m s–1) and turbulence (average 42...

Abstract –  Native Murray cod (Maccullochella peelii peelii) are listed as a nationally vulnerable species, whereas non-native common carp (Cyprinus carpio) are widespread and abundant. Understanding key aspects of life history, such as movement patterns and habitat selection by juvenile Murray cod and common carp, might be useful for conserving Mu...

This study evaluated attraction and passage of native fish through an automated fish lock on the tropical Fitzroy River in north-eastern Australia. In 69 samples (24 h each) taken at the exit and entrance of the fish lock, 17 fish species and 13 402 individuals were collected, at a maximum rate of 3317 fish per day. During low river flows, the fish...

Abstract An 8-m long experimental fishway was trialled at three different slopes [8.3% (1:12), 14.3% (1:7) and 20% (1:5)] to examine the potential of the single-plane Denil fishway for the passage of small- and large-bodied native fishes in Australia. Fish between 45 and 630 mm ascended the fishway. The lowest slope enabled the full size range of b...

Trapped common carp Cyprinus carpio display a pronounced escape behavior of jumping out of the water; this behavior is not exhibited by most Australian native fishes. Hence, there appears to be an important opportunity to exploit the unique jumping behavior of nonnative common carp to aid selective removal. We report on the Williams cage, a simple...

Abstract  Introduced common carp, Cyprinus carpio L., is the most abundant large fish in the Murray-Darling Basin and past studies have considered it non-migratory. Movement information is, however, important for targeting control efforts to appropriate habitats and spatial scales. Movement patterns of common carp in the Murray River were investiga...

Sectioned sagittal otoliths have been validated for age determinations of golden perch Macquaria ambigua to age 9. However, previous studies have estimated ages up to 26 years. I used two known-age fish of ages 20 and 22 years to confirm that sectioned otoliths are valid for estimating the true age of old golden perch. The present study has validat...

Non-native common carp (Cyprinus carpio L.) are the most abundant large-bodied fish in the Murray–Darling Basin. The abundance of common carp larvae and young-of-the-year appears to increase after flooding, although the relative contribution of floodplain habitats compared to riverine areas remains unresolved. Larval nets were used monthly from Sep...

In Australia, wetlands are often the primary sites for carp recruitment within a catchment, and are also the habitats where carp are most likely to detrimentally impact water quality and fish and invertebrate community composition. The most detrimental carp impacts are likely to be associated with large biomass populations of adult carp, but other...

Golden perch Macquaria ambigua (Percichthyidae) and silver perch Bidyanus bidyanus (Terapontidae) are two potamodromous fish species of the Murray-Darling river system in southeastern Australia. Ageing of these species using thin sections of the sagittal otoliths and validation with known-age fish revealed: they live for over 26 years; male and fem...

The relationship between the number of rings present in sagittal otoliths and the age of barramundi, Lates calcarifer (Bloch, 1790) [Centropomidae], was investigated by examining cross sectioned otoliths of 37 tagged fish of known age between 1 and 5 years from the Johnstone River, north Queensland. Concentric rings were clearly visible in all otol...

The effectiveness of a vertical-slot fishway on the Burnett River barrage for facilitating migration of fish was assessed. In 100 samples taken at the top and bottom of the fishway, over 52 000 fish representing 34 species were collected at a maximum rate of 4500 fish per day. In contrast, less than 2000 fish ascended the original pool-and-weir fis...

Fishways for salmon in temperate rivers have often been successful, but salmonid-type fishways for non-salmonid species in tropical and subtropical rivers have frequently failed. This study assessed the effectiveness of modifying a salmonid-type pool-and-weir fishway into a vertical-slot design on a tidal barrage on the subtropical Fitzroy River, i...

This the cover & chapter section of the 1997 New South Rivers Survey of Fish and Fish Health. This book was edited by John Harris and Peter Gehrke, and the overall program coordinated by John Harris and Peter Gehrke. The list of other substantive contributors is very long, and includes: Harris JH; Gehrke PC; Bruce A; Brown P; Curran SJ; Driver P;...