Native fish stocking of rivers: discriminating between hatchery-reared and wild fish. Stocking of fish is widely used in attempts to restore native fish populations. Little is known of the fate of stocked fish or the effects of stocking on resident populations. We will develop and evaluate protocols for chemical marking of otoliths of hatchery-reared fish so that their source can be determined. Experimental stocking of hatchery-reared fish will be undertaken and population structure and sourc ....Native fish stocking of rivers: discriminating between hatchery-reared and wild fish. Stocking of fish is widely used in attempts to restore native fish populations. Little is known of the fate of stocked fish or the effects of stocking on resident populations. We will develop and evaluate protocols for chemical marking of otoliths of hatchery-reared fish so that their source can be determined. Experimental stocking of hatchery-reared fish will be undertaken and population structure and source of stocked versus wild fish determined in stocked and unstocked rivers. Natural chemical signatures will also help determine important recruitment areas. The outcomes will allow fisheries managers to make informed decisions regarding stocking strategies.Read moreRead less
Diadromous stream fishes: a model system for investigating sources of variation in recruitment. Our aim is to examine the relationship between adult abundance and recruitment in local populations of a diadromous stream fish to identify the source(s) of variation in recruitment. We will accomplish this by measuring larval production and recruitment among streams that vary in adult abundance, strength of settlement cues, and potential for larval dispersal. We will also use environmental markers of ....Diadromous stream fishes: a model system for investigating sources of variation in recruitment. Our aim is to examine the relationship between adult abundance and recruitment in local populations of a diadromous stream fish to identify the source(s) of variation in recruitment. We will accomplish this by measuring larval production and recruitment among streams that vary in adult abundance, strength of settlement cues, and potential for larval dispersal. We will also use environmental markers of larval origin to quantify the degree of self-recruitment and dispersal within/among populations. The results will broaden our understanding of the influence of local (production, habitat) versus regional (dispersal) processes to local population dynamics, information needed for effective stream management.Read moreRead less
Open or closed? Dispersal and recruitment in populations of aquatic invertebrates with spatially distributed resources. The general aim of this research is to examine the contribution of fertilised eggs and recently hatched juveniles to the local population dynamics of some stream invertebrates. It seems likely that these stages act as population 'bottlenecks' , and our research will quantify the relations between these two stages and between neonates and mature larvae. Our research will also ....Open or closed? Dispersal and recruitment in populations of aquatic invertebrates with spatially distributed resources. The general aim of this research is to examine the contribution of fertilised eggs and recently hatched juveniles to the local population dynamics of some stream invertebrates. It seems likely that these stages act as population 'bottlenecks' , and our research will quantify the relations between these two stages and between neonates and mature larvae. Our research will also indicate whether these populations are likely to be closed (i.e., groups of individuals are relatively isolated) along channels or not. We believe our results will show much stream research focuses on the wrong life-stages; practices of river management may need re-assessment.Read moreRead less
The evolution of egg retention and sex allocation: a phylogenetic contrasts study using facultatively ovoviviparous thrips. Australian idolothripine thrips provide an unparalleled opportunity for investigating the evolution of reproduction. They constitute the only group to contain many species in which the females choose among live birth, egg laying or both. They also choose the sex of each offspring. We will use phylogenetics and experimentation to understand the evolutionary pressures that le ....The evolution of egg retention and sex allocation: a phylogenetic contrasts study using facultatively ovoviviparous thrips. Australian idolothripine thrips provide an unparalleled opportunity for investigating the evolution of reproduction. They constitute the only group to contain many species in which the females choose among live birth, egg laying or both. They also choose the sex of each offspring. We will use phylogenetics and experimentation to understand the evolutionary pressures that led to and maintain live birth and the allocation of sex. This will produce new insights into fundamental questions about the evolution of animal reproduction. Our collaborative approach will make Australian thrips and research an international cornerstone in the biology of reproductive evolution.Read moreRead less
Plant-herbivore interactions: a model two-species system from northern Australia. The proposed research addresses a critical aspect of magpie goose ecology. Understanding the interaction between the birds and the bulbs is critical to respond effectively to past and threatened losses of important sedge habitats to sea level rise. This knowledge will inform management of the Kakadu World Heritage Site and an iconic waterfowl of great cultural and economic significance. In addition to their importa ....Plant-herbivore interactions: a model two-species system from northern Australia. The proposed research addresses a critical aspect of magpie goose ecology. Understanding the interaction between the birds and the bulbs is critical to respond effectively to past and threatened losses of important sedge habitats to sea level rise. This knowledge will inform management of the Kakadu World Heritage Site and an iconic waterfowl of great cultural and economic significance. In addition to their importance as a Gondwanan relic and sole member of the Family Anseranatidae, the species is an important food-source for Aboriginal people, and tourists travel to the Kakadu wetlands to witness huge dry season congregations.Read moreRead less
Patterns of connectivity and hot-spots of recruitment: a basis for prioritising high value coastal rivers. Provision of water for agricultural, industrial and residential use is becoming increasingly difficult in Australia. By determining the need for important migratory fish species to have access to marine conditions, this project aims to assist managers to identify river systems where changing flow patterns will be particularly detrimental. The project will provide information about the ne ....Patterns of connectivity and hot-spots of recruitment: a basis for prioritising high value coastal rivers. Provision of water for agricultural, industrial and residential use is becoming increasingly difficult in Australia. By determining the need for important migratory fish species to have access to marine conditions, this project aims to assist managers to identify river systems where changing flow patterns will be particularly detrimental. The project will provide information about the need for artificial opening of estuary mouths, fish ladders and other practical means to ensure the continued survival of these species. Read moreRead less
Rapid evolution, and the dynamics and stability of ecological communities. Population sizes of species go up and down and often we do not know why. This is a problem because changes in population size underpin more complex ecological change, and understanding why population sizes change affects our ability to manage environmental impacts, and threatened, harvested and pest species. The aim of this project is to discover how rapid evolution – evolution occurring over just a few generations – driv ....Rapid evolution, and the dynamics and stability of ecological communities. Population sizes of species go up and down and often we do not know why. This is a problem because changes in population size underpin more complex ecological change, and understanding why population sizes change affects our ability to manage environmental impacts, and threatened, harvested and pest species. The aim of this project is to discover how rapid evolution – evolution occurring over just a few generations – drives changes in population sizes of plants in Australian freshwater ecosystems. By focusing on this fundamental yet poorly understood process, our results promise to rewrite our understanding of the causes of change in ecological communities, while highlighting a unique and little studied component of Australia’s biota.Read moreRead less
Conservation biology of the largest Australian freshwater tortoise, the broad-shelled tortoise, Chelodina expansa - rare and endangered or cryptic and secure? The Murray is a highly managed river, with flows controlled by catchments and diversions. The combined impacts of water resource development, habitat modification and introduced species are astonishingly diverse, and include extinctions of some fish and invertebrates and depression of populations of many other species. Australia's largest ....Conservation biology of the largest Australian freshwater tortoise, the broad-shelled tortoise, Chelodina expansa - rare and endangered or cryptic and secure? The Murray is a highly managed river, with flows controlled by catchments and diversions. The combined impacts of water resource development, habitat modification and introduced species are astonishingly diverse, and include extinctions of some fish and invertebrates and depression of populations of many other species. Australia's largest chelid turtle, the broad-shelled turtle, is a high-level consumer thought to be particularly sensitive to these changes. We will use an innovative combination of non-destructive technologies to investigate the conservation biology of this species in the Lower Murray, where it is regarded as rare and where its biology is virtually unknown to inform conservation management and restoration initiativesRead moreRead less
Phylogeography, Conservation Genetics and Stocking Management of Perches and Basses. This project will use DNA data to address fundamental questions about the origin and maintenance of biodiversity in a popular and widely distributed fish group. From a conservation perspective, the project will produce a benchmark about management of fish resources. We will investigate questions related to important conservation issues (including the recovery plan of a nationally threatened species) and the mana ....Phylogeography, Conservation Genetics and Stocking Management of Perches and Basses. This project will use DNA data to address fundamental questions about the origin and maintenance of biodiversity in a popular and widely distributed fish group. From a conservation perspective, the project will produce a benchmark about management of fish resources. We will investigate questions related to important conservation issues (including the recovery plan of a nationally threatened species) and the management of stocking activities in recreational fisheries of coastal and inland waters. The latter is particularly relevant to rural communities since they provide both social and economic benefits to rural people.Read moreRead less
The fox and the turtle: is predator control in riparian systems effective for threatened species. We address the conservation impact of an introduced predator (the fox) on threatened species. Few studies have addressed the influence of feral predators on riparian species. We will experimentally evaluate the effectiveness of feral species control by examining demography of turtles. Turtles are an ideal species for such studies as they are long-lived, so population models can be applied. Result ....The fox and the turtle: is predator control in riparian systems effective for threatened species. We address the conservation impact of an introduced predator (the fox) on threatened species. Few studies have addressed the influence of feral predators on riparian species. We will experimentally evaluate the effectiveness of feral species control by examining demography of turtles. Turtles are an ideal species for such studies as they are long-lived, so population models can be applied. Results of this work will be significant in (a) empirical testing of rigorous, experimentally-based methodology to quantify demographic effects of predator-prey interactions, and (b) providing a robust basis for management that may serve as a template for feral predator control elsewhere.Read moreRead less