The intertidal flora and fauna of S.E. Australia (Robe, South Australia to S. New South Wales, including Tasmania) is described in terms of its horizontal and vertical distribution. A detailed account of intertidal zonation, on the central Victorian coast and Bass Strait islands, is included. Environmental features are discussed and sea temperature data for Pt. Lonsdale is presented. / Analysis of the marine flora in S.E. Australia suggests that the concept of separate biogeographic provinces in this region is invalid and the flora is best interpreted as a continuum.

Fish larvae in Australian waters have been studied progressively in the last 2-3 decades including the distribution and abundance of taxa, growth and age, their prey and predators. However, the effect of nutrient limitation on ichthyoplankton is unstudied, particularly in the oligotrophic Australian waters. My study was aimed to examine the effect of natural or anthropogenic nutrients on the abundance, distribution, growth and condition of fish larvae along-shore of the NSW coast (latitude 30-34S), where the East Australian Current departs the NSW coast and generates local upwelling of cool nutrient-rich water. This study shows no significant difference in the total abundance or diversity of either larval fishes amongst the 112 taxa (111 families and 1 order), among regions within or upstream of the upwelling. However in both months, there were distinctive ichthyoplankton assemblages at the family level. The Carangidae, Labridae, Lutjanidae, Microcanthidae, Myctophidae and Scombridae were more abundant in the EAC or oceanic water masses, while the Callionymidae, Clupeidae, Platycephalidae, Sillaginidae and Terapontidae were mostly found in the surface or deep upwelled/uplifted water masses. This pattern is observed in other ichthyoplankton studies and may be a general and useful method to determine mixing of water masses. Larvae of silver trevally (Pseudocaranx dentex) and yellowtail scad (Trachurus novaezelandiae) were generally larger and less abundant in the topographically induced upwelling region, than north of the region in pre-upwelled conditions of the East Australian Current. Both species were mostly at the preflexion stage (less than 4.3 mm in body length and less than 10 days old) in the pre-upwelled conditions, particularly during November, and proportionally more larger and older larvae in the upwelled waters (mostly post-flexion, greater than 4.3 mm in body length and greater than 10 days old). Ages from sagittal otoliths ranged from 2-25 increments (~days) and exhibited linear growth for both species and months over the size range (3-15 mm standard length). The otolith radius-length relationship and the growth rates were similar between species and months, despite the 3-4C difference between months. Overall growth rates of the younger larvae were uniform throughout the entire sampling area (0.5-0.6 mm.d-1), while older larvae grew significantly faster in the upwelled water (0.41 mm.d-1) compared to the non-upwelled conditions (0.34 mm.d-1). Both species tended to be depleted in 13C in the upwelling region (from ???18.5 to ???19.0), consistent with expected ratios from deeper water, whereas the 15N composition tended to increase in Pseudocaranx, but decrease in Trachurus indicating different diets and possibly trophic level. The early life history of both species indicates spawning in pre-upwelled waters, but larval transport into upwelled waters is necessary for faster growth in the post-flexion stage. The assemblage of larval fishes did differ between the upwelled region and a region south of Sydney???s deepwater outfalls, but the difference was ascribed to a latitudinal effect and the EAC. Both larval carangids were enriched in 15N, possibly due to the enriched dissolved organic matter of primary treated sewage. In summary, this study found that the larval fish community can provide a biological means to trace water masses, and estimate their degree of mixing. Remarkably there was no significant effect of upwelling or sewage addition to the abundance or diversity of larval fish, in the nutrient poor waters of the East Australian Current. Larval carangids and pilchards were abundant in late spring off northern NSW, and their early life histories were inferred. Both larval carangid species seem to be spawned in the EAC waters, but as post-flexion larvae grew faster in the upwelled zone. Pre-flexion (less than 10 day old) larval carangids of both genera indicated spawning in the EAC, and the rarer post-flexion (greater than 10 days old) carangids grew faster in the upwelled waters. Here, both genera had stable isotope signatures characteristic of upwelled waters for carbon, but had different nitrogen signatures, indicative of different diets and trophic level status. Larval pilchards actually grew more slowly in the upwelling region, as observed in coastal waters off Japan, and their nursery grounds may be further offshore in the Tasman Front, analogous to their early life history in the Kuroshio Extension.

Palaeobotany illuminates past environments by relating the fossilised species to the existing geological conditions. This has previously been done with fossilised leaves and spores but not with fossilised wood. The recovery of a significant quantity of wood from an area of Tertiary sediments in New South Wales, enabled the used of fossilised wood as a palaeoenvironmental tool. Tertiary sedimentary deposits of south eastern Australia are diverse lithologically, occupy distinct areas and are limited in vertical and horizontal extent. However, samples in museum collections together with samples from field work and descriptions of fossil wood from previous researchers enabled an analysis of the fossil wood. The geological and palaeontological aspects of the fossil wood were considered for each specimen. Only specimens with precise information concerning location and description of the sedimentary deposits in which the specimens were found were investigated. Lithology, sedimentary structures and the relationship with surrounding geological units were also considered. The samples were then classified and identified. It was possible to identify fossil wood to Family level by comparison with existing taxa. In the majority of cases, identification to species level was not possible due to the lack of detail in the specimen and because features such as colour cannot be used with fossilised specimens. With Australian fossilised wood, a systematic nomenclature based on structure observed within the palaeotaxa, would be more relevant. Comparisons of cell structures with previous work on palaeoenvironmental indicators was found to be possible. Fossil wood has two uses. Firstly, as a local environmental indicator, usually in conjunction with sedimentological data, assessing the rate and direction of water flow, types of depositional environments and localised floral assemblages. Secondly, as an indicator of regional climate. Within any one particular time period, comparisons between the cellular structures of wood found in different parts of south eastern Australia show gross changes in cell size, mean growth ring size and vessel size, which enabled generalisations about climate for each epoch in the Tertiary. Palaeoclimatic indicators from the wood concurred with previous climatic interpretations based on palynology and sedimentology. Cool conditions during the Palaeocene were clearly indicated by small cells and small growth rings which gradually increased throughout the remainder of the Tertiary. Several areas e.g., Dargo High Plains, where cold conditions existed in isolation could be clearly distinguished. This corresponds with the gradual northward movement of the Australian plate with consequent increasing temperatures on the mainland.

Fish larvae in Australian waters have been studied progressively in the last 2-3 decades including the distribution and abundance of taxa, growth and age, their prey and predators. However, the effect of nutrient limitation on ichthyoplankton is unstudied, particularly in the oligotrophic Australian waters. My study was aimed to examine the effect of natural or anthropogenic nutrients on the abundance, distribution, growth and condition of fish larvae along-shore of the NSW coast (latitude 30-34S), where the East Australian Current departs the NSW coast and generates local upwelling of cool nutrient-rich water. This study shows no significant difference in the total abundance or diversity of either larval fishes amongst the 112 taxa (111 families and 1 order), among regions within or upstream of the upwelling. However in both months, there were distinctive ichthyoplankton assemblages at the family level. The Carangidae, Labridae, Lutjanidae, Microcanthidae, Myctophidae and Scombridae were more abundant in the EAC or oceanic water masses, while the Callionymidae, Clupeidae, Platycephalidae, Sillaginidae and Terapontidae were mostly found in the surface or deep upwelled/uplifted water masses. This pattern is observed in other ichthyoplankton studies and may be a general and useful method to determine mixing of water masses. Larvae of silver trevally (Pseudocaranx dentex) and yellowtail scad (Trachurus novaezelandiae) were generally larger and less abundant in the topographically induced upwelling region, than north of the region in pre-upwelled conditions of the East Australian Current. Both species were mostly at the preflexion stage (less than 4.3 mm in body length and less than 10 days old) in the pre-upwelled conditions, particularly during November, and proportionally more larger and older larvae in the upwelled waters (mostly post-flexion, greater than 4.3 mm in body length and greater than 10 days old). Ages from sagittal otoliths ranged from 2-25 increments (~days) and exhibited linear growth for both species and months over the size range (3-15 mm standard length). The otolith radius-length relationship and the growth rates were similar between species and months, despite the 3-4C difference between months. Overall growth rates of the younger larvae were uniform throughout the entire sampling area (0.5-0.6 mm.d-1), while older larvae grew significantly faster in the upwelled water (0.41 mm.d-1) compared to the non-upwelled conditions (0.34 mm.d-1). Both species tended to be depleted in 13C in the upwelling region (from ???18.5 to ???19.0), consistent with expected ratios from deeper water, whereas the 15N composition tended to increase in Pseudocaranx, but decrease in Trachurus indicating different diets and possibly trophic level. The early life history of both species indicates spawning in pre-upwelled waters, but larval transport into upwelled waters is necessary for faster growth in the post-flexion stage. The assemblage of larval fishes did differ between the upwelled region and a region south of Sydney???s deepwater outfalls, but the difference was ascribed to a latitudinal effect and the EAC. Both larval carangids were enriched in 15N, possibly due to the enriched dissolved organic matter of primary treated sewage. In summary, this study found that the larval fish community can provide a biological means to trace water masses, and estimate their degree of mixing. Remarkably there was no significant effect of upwelling or sewage addition to the abundance or diversity of larval fish, in the nutrient poor waters of the East Australian Current. Larval carangids and pilchards were abundant in late spring off northern NSW, and their early life histories were inferred. Both larval carangid species seem to be spawned in the EAC waters, but as post-flexion larvae grew faster in the upwelled zone. Pre-flexion (less than 10 day old) larval carangids of both genera indicated spawning in the EAC, and the rarer post-flexion (greater than 10 days old) carangids grew faster in the upwelled waters. Here, both genera had stable isotope signatures characteristic of upwelled waters for carbon, but had different nitrogen signatures, indicative of different diets and trophic level status. Larval pilchards actually grew more slowly in the upwelling region, as observed in coastal waters off Japan, and their nursery grounds may be further offshore in the Tasman Front, analogous to their early life history in the Kuroshio Extension.

The meiofauna of a mangrove forest in the River Barwon estuary was studied by means of surveys and field experiments. Distinctive assemblages of meiofauna were described from the sediment and pneumatophores of the ecosystem. Fine resolution of phytal habitats was demonstrated, and particular assemblages of meiofauna were characteristic within habitat provided by dominant epibionts. Distribution of the meiofauna within leaf litter revealed high turnover rates of nematodes, and some factors controlling detrital assemblages were assessed. The vertical profile of sedimentary meiofauna was examined, and changes in abundance were related to the tychopelagic habit of many taxa at high tide. Dispersal within the water column was confirmed by pelagic trapping, and colonisation of mimic pneumatophores was investigated. The amount of algal cover, effects of grazing by gastropods, and rugosity of the colonised surface were shown to influence meiofauna colonisation of mimic pneumatophores. Establishment and persistence of patchy distributions of meiofauna at scales of less than 10 m in an intertidal environment was demonstrated, and it was concluded that this was due to the dynamic nature of assemblages rather than their integrity.

Rivers around the world are under increasing pressure from a variety of human activities. Effective management of riverine landscapes requires an ecosystem approach and one that recognises the complex interactions between their physical, chemical and biological components. Perceptions of pattern and process are central to our understanding of riverine landscapes. Pattern and process operate over multiple scales to produce heterogeneous mosaics of landscape patches that change over time. Hierarchical patch dynamics provides a useful approach to unravel pattern and process at multiple scales in riverine landscapes. This thesis adopts a hierarchical patch dynamics approach to investigate floodplain sediment and nutrient dynamics within the Barwon-Darling River in South Eastern Australia. The flow regime of the Barwon-Darling River is highly variable. As a result, it has a complex channel cross section featuring inset-floodplain surfaces that occur at multiple elevations within the channel trough. These surfaces formed the focus of this study. The texture of inset- floodplain surface sediments displays a patchy spatial distribution and one that did not reflect lateral or longitudinal gradients within this floodplain landscape. Rather a sediment textural patch mosaic was identified. Nutrient concentrations associated with the surface sediments of the inset-floodplains were also shown to vary significantly resulting in a nutrient patch mosaic. This spatial nutrient mosaic was enhanced by factors including the surface elevation of the floodplain surface. Sediment and nutrient exchange between the river channel and inset-floodplain surfaces was measured during several flows in 2001, 2002 and 2005. Pin and sediment trap data showed that significant quantities of sediment were exchanged between the river channel and floodplain surfaces during inundation with both cut and fill processes occurring. Patterns in sediment exchange appear to be related to local sediment supply and seasonal sediment exhaustion, rather than the top down geomorphic constraints considered. These material exchanges resulted in a change to the spatial configuration of the sediment textural patch mosaic. Distinct new sediment textural patches were created following inundation, while other patches were lost post inundation and other patches changed sediment textural character to move into pre-existing patches. Thus a truly dynamic sediment textural mosaic exists within this floodplain landscape. Nutrient concentrations associated with floodplain sediments also changed over time. While nutrient concentrations increased after the December 2001 flow event, they generally decreased after the March 2002 event, highlighting their dynamic nature over time. The spatial distribution of nutrient concentrations also varied over time, with a 40 percent change to the nutrient mosaic as a result of the March 2002 flow event. In addition to the influence of the changing physical template (sediment texture mosaic), nutrient concentrations were shown to be influenced by rainfall processes on non flooded surfaces, and also a number of top-down constraints and bottom-up influences operating over multiple spatial scales. Overall, the inset-floodplains studied in this thesis acted primarily as sediment and nutrient sinks, and were a source for dissolved nutrients. Nutrient exchange was associated with the exchange of sediments in this riverine landscape, over both inter-flow and decadal timescales. It was demonstrated that water resource development within the catchment reduced the number, magnitude and duration of flow events down the Barwon-Darling River and as a result reductions in the exchange of sediment, associated and dissolved nutrients between inset-floodplains and the main river channel were calculated. The greatest reductions were with the release of dissolved nutrients (42-25 percent) and the exchange of sediment and associated nutrients from high level surfaces (43 percent). Effective conservation and management of riverine ecosystems must occur at the correct scale. This study identified potential nutrient hotspots at several scales in the Barwon-Darling floodplain landscape that could be targeted by management. The low predictability of the location of nutrient hotspots at the inset-floodplain scale over time means that environmental flows should be targeted at high level surfaces (<25 000 MLD-1) that provide long term sources of carbon to the river channel. Conserving flows of this magnitude will also reinstate flow variability, an important facet of the Barwon-Darling River?s hydrology that has been changed by water resource development. The research presented in this thesis highlights the importance of not only considering pattern and process at multiple scales, but also the way in which these processes influence landscape patterns over time, leading to the identification of the appropriate scales that can best be targeted for the conservation of these systems.

Healthy riparian vegetation has a positive impact on the adjacent river. Unfortunately, riparian vegetation is often threatened by human impacts such as dam construction and clearing. To gain the knowledge underlying the effects of such impacts and to aid riparian rehabilitation, the objective of this thesis was: to determine riparian vegetation association with, and response to, variation in fluvial geomorphology over several scales and consequently to fluvial disturbance. Only woody riparian plant species were considered. Flood disturbance was the unifying theme of this thesis. Linked to this theme and arising from the main objective was the supposition that plant interactions with the abiotic environment, but not biotic interactions between species, control riparian species distribution because of frequent fluvial disturbances. Woody riparian vegetation and riverine environmental variables were recorded along the upper Murrumbidgee River at three spatial scales based on a geomorphic hierarchy for Chapter 2. Multivariate analysis was used to group species and to associate environmental variables with vegetation at the three spatial scales. Observations at the two larger scales, of river segment (site) and riparian reach (transect), identified a river-longitudinal speciescomposition gradient associated with geology, river width and stream channel slope. Observations at the smallest scale of geomorphic units (plot) identified a lateral riparian gradient and also the longitudinal gradient; these gradients were associated with geomorphic variation, land use, plot elevation and also river longitudinal variables. Using the same data set, but varying the spatial scale of analysis caused the species composition pattern to change between scales. Increase in scale of observation, that is from geomorphic unit to reach and segment scales, resulted in disproportionate importance of rarer species and decreased importance of some key riparian species at the larger scales. It would appear that in this instance the geomorphic unit scale best described patches of different species composition because this scale had high spatial resolution and was also able to identify multiple gradients of environmental variation. It was recommended that riparian sampling take place at scales that represent dominant gradients in the riparian zone. These gradients are represented by geomorphic scales, indicating the appropriateness of using geomorphic based scales for observation of riparian vegetation. Chapter 3 considered whether there is a geomorphic template upon which riparian vegetation is patterned and whether it is associated with process variables, such as flooding and soil type. This question was investigated at different spatial scales in three ways: i) by an experiment to determine whether soil nutrient condition affects plant growth; ii) by graphical analysis of trends between geomorphic units, species and process variables; and iii) by analysis of vegetation distribution data. The smallest scale (meso) found experimental differences in plant growth because of soil type. Plants growing in sand had the lowest performance, with an average plant Relative Growth Rate (RGR) of 0.01, compared to plants growing in soils with small amounts of silt or clay particles, with an average plant RGR of 0.04. This pattern was attributed to differences in nutrients. Clear relationships were demonstrated at the larger geomorphic unit scale between species distribution and process variables. For example, hydrology and substratum type were found to be associated with geomorphic units and species. The largest scale considered in Chapter 3 was the riparian reach scale. At this scale species were clearly grouped around reach type. Therefore, geomorphology was considered to be a template for riparian species distribution. Findings in this chapter suggested that geomorphic variables should be good predictors of riparian species distribution. This hypothesis was tested and supported in Chapter 6. The experiments reported in Chapter 4 aimed to determine whether inundation depth and duration affected plant performance and survival for five common riparian zone species. Riparian seedling patterns in the field were also compared with experimental results to test whether species performance was reflected by field distribution. The experiments that were conducted included an inundation period and depth experiment, and a survival period test whilst under complete inundation. Biomass and height relative growth rates were determined, and the results were analysed using factorial Analysis of Variance. Obligate riparian species (Callistemon sieberi, Casuarina Cunninghamiana, Leptospermum obovatum) were found to be tolerant of inundation duration and depth, to the point where inundation provided a growth subsidy. On the other hand, non-obligate riparian species (Acacia dealbata, Kunzea ericoides) were either just tolerant of inundation or showed a negative growth response. For instance, C. sieberi demonstrated an average height RGR of 0.04 after complete inundation and 0.007 when not inundated, while A. dealbata had an average height RGR of 0.001 after complete inundation and 0.01 when not inundated. These experimental findings were found to closely reflect both seedling and adult plant distribution in the field such that inundation tolerant species were found close to the river and intolerant species further away. Thus, the conclusion was drawn that riparian species establishment and distribution is affected by inundation and that change to the flood regime could have serious impacts on riparian zone plant composition. The other aim of this chapter was to determine whether optimum germination temperatures were associated with flood or rainfall. Growth chamber germination trials were conducted at air temperatures of 15�C, 20�C and 25�C to determine the 'best' germination temperature. These germination patterns at different temperatures were then related to annual variation in field temperature, flooding period and rainfall. No evidence was found to suggest a relationship between ideal germination temperature and flood season, rather it was suggested that germination was patchy through time and may simply reflect recent rainfall. Investigations that were reported in Chapter 5 aimed to elucidate relationships between species and flow velocity variables. Two experiments were conducted: i) a flume experiment to determine the effect of flow velocity on plant growth; and ii) an experiment to observe the response of plants to damage (imitating flood damage) and inundation. Field observations of species distribution and flow velocity related variables were also conducted to put the flume results into a real-world context. Treatments for the flume experiment were fast flow velocity (0.74 m s-1), slow velocity (0.22 m s-1) and no velocity (control) but still inundated. All treatments were flooded completely for four days. Subsequent biomass and height relative growth rates were determined, and the results were analysed using factorial Analysis of Variance. Results were unexpected, given that obligate species exposed to the fastest velocity had the highest growth rate with an average height RGR of 0.046, compared to plants in still water, which grew the least with an average height RGR of 0.013. It was hypothesised that this response was because relatively greater carbon dioxide and oxygen levels were available in the moving water compared to the still water. With regard to shoot damage, the species that were nonobligate riparian species lost more leaves from velocity treatment than the obligate riparian species. The cut and flood experiment found growth of the obligate species (Casuarina cunninghamiana) to be greater after cutting than the non-obligate species. Flooding was not found to have an effect in the cut and flood experiment, probably because the period to sampling after flood treatment was longer (4 weeks) than other flooding experiments (3 weeks). Field observations were found to support the experimental findings, with a gradient of species across the riparian zone that reflected potential flood velocities. Therefore, velocity is one of a suite of riparian hydrological factors that are partially responsible for the gradient of species across the riparian zone. Potentially the absence of flooding could result in a homogeneous mix of species, rather than a gradient, except on the very edge of the river. The study that was reported in Chapter 6 investigated a technique for predicting riparian vegetation distribution. One of the aims of this investigation was to address a current riparian rehabilitation shortfall, which was how to objectively select species to plant for rehabilitation. Field data were collected from three confined river valleys in south-eastern New South Wales. Using data on plant species occurrence and site and plot measures of soils, hydrology and climate, an AUSRIVAS-style statistical model, based on cluster and discriminant analysis, was developed to predict the probability of species occurrence. The prediction accuracy was 85 % when tested with a separate set of plots not used in model construction. Problems were encountered with the prediction of rarer species, but if the probability of selection was varied according to the frequency of species occurrence then rarer species would be predicted more often. Various models were tested for accuracy including three rivers combined at the geomorphic unit (plot) scale and riparian reach (transect) scale in addition to a Murrumbidgee River plot scale model. Surprisingly, the predictive accuracy of the all rivers and single river models were approximately the same. However, the difference between the large scale and small scale models pointed to the importance of including small scale flood-related parameters to predict riparian vegetation. When these riparian predictions were compared to predictive outcomes from a hill slope model, which was assumed to be affected by fewer disturbances (i.e. flooding), predictive accuracies were not very different. Overall though, predictive accuracy for riparian vegetation was high, but not good enough to support the supposition that riparian vegetation is abiotically controlled because of frequent flood disturbance. Nevertheless, geomorphology and consequently flood effects are still important for the determination of the riparian community composition. Overall, riparian vegetation was found to be closely linked to its environment (evidenced in Chapters 2, 3, 4, 5) in a predictable manner (Chapter 6). Species pattern relied on flood disturbance affecting species distribution. Some riparian species were found to be highly tolerant of flooding and gained a growth advantage after flooding (Chapters 4 and 5). Therefore, flood tolerance was important for the formation of a species gradient across the riparian zone. These species tolerances and growth requirements reflect riparian geomorphic pattern (Chapter 3), which was suggested to form a template on which riparian vegetation is structured.

Baiting with sodium monofluoroacetate (1080) to protect lambs (Ovis aries) from red foxes (Vulpes vulpes L.) has become more frequent in NSW and other parts of Australia during the last 10 years despite the lack of reported evidence evaluating the effects of fox baiting on lamb survival. NSW Agriculture has developed fox control recommendations aimed at minimising impact, but these guidelines have not been tested experimentally. Defining the extent of a pest problem and the effectiveness of pest control are key components of a strategic approach to vertebrate pest management as it is the damage of pests that justifies their control. This thesis describes an experimental evaluation of the recommended practice of fox control in NSW. The effects of three levels of fox control were tested in the experiment; no treatment, baiting once a year before lambing (the recommended practice) and baiting three times a year (thought to be the maximum farmers would instigate). Each treatment had two replicates. No previous manipulative experiment using synchronous controls and matched replicates has been undertaken to test the effects. The study quantifies the level of fox predation on healthy lambs and the level of predation on lambs that had other causes including illness and mismothering contributing to this fox predation. It also examines the response of the fox population, lamb predation and lambing outcomes to different levels of fox control. The cost effectiveness of fox control is examined in relation to lamb predation and an investigation of the optimum level of fox control is begun. The experiment also provides the first chance to consider the examination of multiple response variables and the scale of field ecology experiments required to recognise a significant response and avoid a Type II error due to between replicate variability even with tightly controlled site selection criteria to standardise experimental sites, and with the synchrony of experimental control and treatment surveys. The study occurred on five sheep properties near Boorowa (34°28'S, 148°32'E) and Murringo (34°18'S, 148°3 1'E) in south-eastern Australia. The terrain was undulating to hilly with a maximum elevation of 660 m above sea level. The main agricultural enterprises in the district are Merino wool, fat lamb and beef cattle production and winter cereal cropping. The native vegetation of Eucalyptus woodland has been mostly cleared, though remnant patches occur. Most of the area is now sown with pasture of Phalaris tuberosa, Lolium spp. and clover Trifolium spp.. The experimental properties grazed self-replacing Merino flocks, primarily for wool production, so lamb survival was vital to the economic operation of the farm. Over 50 selection criteria including lamb survival rates, ewe fertility and bloodline, sheep management practices, climate and habitat features that affect lamb survival, past fox control practices and prey species were used to select sites Sites were representative of most sheep farming properties in the region, but were also extremely similar in factors that affected fox abundance and ewe and lamb survival, thus minimising variation between replicate sites. The manufactured meat baits used to poison foxes contained 3 mg of sodium monofluoroacetate (compound 1080). A replacement baiting program was carried out in 1995 and 1996. Fox control programs were carried out over the experimental units and adjacent buffer zones covering approximately two fox territories, approximately 6km2, around the lambing paddock under study. The recommended fox control practices described by NSW Agriculture also included neighbouring farmers taking part in an extended group baiting program. In all the area baited at varying intensities totalled 3400 km2. Synchronised lambing with neighbours was a further recommended practice to reduce fox predation and was carried out on these sites. Lambing occurred during a six to eight week period in late winter on all sites, a practice known as 'spring lambing', and on many surrounding properties so a surplus of lambs was available to foxes over a relatively short time. The benefits of fox control were measured directly as enhanced lamb survival derived from differences in lamb marking rates between ultrasounded flocks of approximately 1000 ewes and the predation of lambs was measured from over 2000 lamb carcases post-mortemed in 1994, 1995 and 1996. A mean of 138 lambs were expected at ultrasounding from 100 ewes and 113 lambs per 100 ewes were alive at lamb marking. There was no significant (P>0.05) effect of fox control on lambing performance (the number of lambs per 100 ewes that lambed) Fox predation was inferred as the cause of lamb death in a minimum of 0.8% and a maximum of 5.3% of lamb carcases during 1995 and 1996. There was a significant (P<0 05) effect of fox control on the minimum possible percentage of lamb carcases classified as healthy lambs killed by foxes, with the percentage declining from 1.50% (no fox control), to 0.90% (fox control once per year) to 0.25% (fox control three times per year). There was also a significant (P<0.005) effect of fox control on the maximum possible percentage of lamb carcases classified as healthy lambs killed by foxes with the percentage declining from 10.25% (no fox control), to 6.50% (fox control once per year) to 3.75% (fox control three times per year). The observed results were used to estimate the number of treatment replicates needed to be confident of detecting an effect of predator control on lamb marking performance. The estimated numbers were very high if small effects were to be detected. No significant correlation between the fox density and the minimum and maximum possible number of lambs carcases classified as killed by foxes was found. Bait uptake was monitored as were the costs of fox control.

The acanthodians were a common and widespread group of fishes throughout the world during the mid-Palaeozoic. In this study, a full-scale systematic analysis of Silurian to Middle Devonian acanthodian taxa of eastern Australia was undertaken, incorporating a review and updating of historical records and descriptions of taxa. Phylogenetic relationships within the group and with other early gnathostomes are uncertain. The structure, function and modes of growth of acanthodian scales were described and investigated, and these features were used for comparisons between different taxa within the group, and between acanthodians and other early vertebrates. Histological and morphological characters of the scales were incorporated in a cladistic analysis of genera erected for articulated fish. This analysis did not support the traditional ordinal level groups, the Climatiida, Ischnacanthida and Acanthodida. Therefore, the highest taxonomic level used in the study was the family. Rarely were acanthodians preserved as articulated fossils. The only examples known from the Silurian-Middle Devonian of Australia are one specimen of the putative acanthodian Yealepis douglasi Burrow & Young 1999 from the Ludlow of Victoria, five specimens of an indeterminate ?ischnacanthidid from the late Givetian of New South Wales and a rich assemblage from the Givetian lacustrine shales of Mt Howitt, Victoria. The latter fauna (originally dated as Late Devonian) includes six incomplete specimens of the culmacanthidid Culmacanthus stewarti Long 1983 and about 60 specimens of acanthodidid Howittacanthus kentoni Long 1986. In contrast, disassociated remains of the group are ubiquitous in microvertebrate faunas from the mid-Palaeozoic of eastern Australia. Although scales of other fish groups are sometimes more common in particular facies, acanthodian elements are found in all depositional environments, from deep shelf marine to transitional to freshwater. Most of the taxa, particularly those only preserved as isolated scales, had not been systematically described by other workers. This thesis incorporates descriptions of new taxa, and revision and updating of other taxa. Several overseas studies have produced biostratigraphic charts based on acanthodian scales. A similar biostratigraphic overview was undertaken based on a systematic analysis of the Early Devonian acanthodians of eastern Australia, permitting comparisons with acanthodian faunas of other regions. Acanthodian scales and fin spines are the most common elements in the few vertebrate faunas that are known from the Silurian of Australia. Diversity and geographic distribution of the acanthodian faunas peaked during the Early Devonian. This study has been hampered by the low numbers of scales in many samples, and by uncertainty over their dating (particularly for the faunas from non-limestone deposits). Nevertheless, the work shows that changes in the marine assemblages are broadly correlated with the pattern of marine transgressions and regressions. Composition of the acanthodian faunas, and their abundance relative to other vertebrates in the assemblages, depend on the depositional environment. This correlation is best illustrated in Lower Devonian deposits, in which acanthodians are the most prolific and diverse. In transitional and marginal marine deposits, thelodonts are dominant, and acanthodians a minor element of the fauna. In off-shore assemblages, acanthodians and placoderms are dominant, and thelodonts are rare or absent. Vertebrate faunas are poor in the earliest Devonian deposits, but become more common by the late Lochkovian, with near-shore assemblages characterized by Trundlelepis cervicostulata and ANostolepis@ guangxiensis, and deeper shelf assemblages by a new genus, possibly assignable to the Ischnacanthidae. The vertebrate record is sparse through the middle Pragian, though AN.@ guangxiensis is present low in the Coopers Creek Limestone (upper sulcatus-pireneae zones), being replaced by Nostolepoides platymarginata, Gomphonchus? bogongensis, and Radioporacanthodes sp. aff. R. (Gomphonchus) liujingensis by the kindlei Zone. Microvertebrate assemblages are more common by the late Pragian (pireneae Zone), with Radioporacanthodes sp. aff. R. liujingensis in deeper shelf deposits, and N. platymarginata and G.? bogongensis dominating near-shore assemblages. The earliest Emsian (dehiscens Zone) is marked by the incoming Cheiracanthoides wangi. Middle Emsian (perbonus-serotinus zones) assemblages are characterized by two new species, possibly assignable to Gomphonchus.The Middle Devonian cosmopolitan association of Cheiracanthoides comptus and AAcanthoides@ dublinensis, which characterizes early Middle Devonian faunas from North America, Europe and China, appears first in the latest Emsian at the serotinus-patulus zone boundary. As well as showing the value of acanthodians in biostratigraphy and as indicators of environmental settings, their use in biogeography was demonstrated. Although many of the acanthodian taxa are endemic, several are also found in other regions. The Silurian to earliest Devonian faunas of eastern Australia are most closely related to coeval Chinese assemblages. Several latest Silurian-earliest Devonian taxa are also recorded from the circum-Arctic region. The late Lochkovian to early Emsian assemblages, particularly from south-eastern Australia, have many taxa in common with Chinese faunas. The mid-Emsian taxa show highest endemicity; and the latest Emsian-Eifelian assemblages have the most cosmopolitan aspect. Acanthodian faunas become rarer and depauperate in the Middle Devonian, particularly in the south-eastern corner, and are mostly in poorly dated, ?fluviatile/marginal marine deposits. This study of acanthodian faunas has encompassed a full scale systematic review of the group in this region, an appraisal of phylogenetic relationships within the group and with other early vertebrates, their palaeoecology, and their use in biostratigraphy and biogeography.

The acanthodians were a common and widespread group of fishes throughout the world during the mid-Palaeozoic. In this study, a full-scale systematic analysis of Silurian to Middle Devonian acanthodian taxa of eastern Australia was undertaken, incorporating a review and updating of historical records and descriptions of taxa. Phylogenetic relationships within the group and with other early gnathostomes are uncertain. The structure, function and modes of growth of acanthodian scales were described and investigated, and these features were used for comparisons between different taxa within the group, and between acanthodians and other early vertebrates. Histological and morphological characters of the scales were incorporated in a cladistic analysis of genera erected for articulated fish. This analysis did not support the traditional ordinal level groups, the Climatiida, Ischnacanthida and Acanthodida. Therefore, the highest taxonomic level used in the study was the family. Rarely were acanthodians preserved as articulated fossils. The only examples known from the Silurian-Middle Devonian of Australia are one specimen of the putative acanthodian Yealepis douglasi Burrow & Young 1999 from the Ludlow of Victoria, five specimens of an indeterminate ?ischnacanthidid from the late Givetian of New South Wales and a rich assemblage from the Givetian lacustrine shales of Mt Howitt, Victoria. The latter fauna (originally dated as Late Devonian) includes six incomplete specimens of the culmacanthidid Culmacanthus stewarti Long 1983 and about 60 specimens of acanthodidid Howittacanthus kentoni Long 1986. In contrast, disassociated remains of the group are ubiquitous in microvertebrate faunas from the mid-Palaeozoic of eastern Australia. Although scales of other fish groups are sometimes more common in particular facies, acanthodian elements are found in all depositional environments, from deep shelf marine to transitional to freshwater. Most of the taxa, particularly those only preserved as isolated scales, had not been systematically described by other workers. This thesis incorporates descriptions of new taxa, and revision and updating of other taxa. Several overseas studies have produced biostratigraphic charts based on acanthodian scales. A similar biostratigraphic overview was undertaken based on a systematic analysis of the Early Devonian acanthodians of eastern Australia, permitting comparisons with acanthodian faunas of other regions. Acanthodian scales and fin spines are the most common elements in the few vertebrate faunas that are known from the Silurian of Australia. Diversity and geographic distribution of the acanthodian faunas peaked during the Early Devonian. This study has been hampered by the low numbers of scales in many samples, and by uncertainty over their dating (particularly for the faunas from non-limestone deposits). Nevertheless, the work shows that changes in the marine assemblages are broadly correlated with the pattern of marine transgressions and regressions. Composition of the acanthodian faunas, and their abundance relative to other vertebrates in the assemblages, depend on the depositional environment. This correlation is best illustrated in Lower Devonian deposits, in which acanthodians are the most prolific and diverse. In transitional and marginal marine deposits, thelodonts are dominant, and acanthodians a minor element of the fauna. In off-shore assemblages, acanthodians and placoderms are dominant, and thelodonts are rare or absent. Vertebrate faunas are poor in the earliest Devonian deposits, but become more common by the late Lochkovian, with near-shore assemblages characterized by Trundlelepis cervicostulata and ANostolepis@ guangxiensis, and deeper shelf assemblages by a new genus, possibly assignable to the Ischnacanthidae. The vertebrate record is sparse through the middle Pragian, though AN.@ guangxiensis is present low in the Coopers Creek Limestone (upper sulcatus-pireneae zones), being replaced by Nostolepoides platymarginata, Gomphonchus? bogongensis, and Radioporacanthodes sp. aff. R. (Gomphonchus) liujingensis by the kindlei Zone. Microvertebrate assemblages are more common by the late Pragian (pireneae Zone), with Radioporacanthodes sp. aff. R. liujingensis in deeper shelf deposits, and N. platymarginata and G.? bogongensis dominating near-shore assemblages. The earliest Emsian (dehiscens Zone) is marked by the incoming Cheiracanthoides wangi. Middle Emsian (perbonus-serotinus zones) assemblages are characterized by two new species, possibly assignable to Gomphonchus.The Middle Devonian cosmopolitan association of Cheiracanthoides comptus and AAcanthoides@ dublinensis, which characterizes early Middle Devonian faunas from North America, Europe and China, appears first in the latest Emsian at the serotinus-patulus zone boundary. As well as showing the value of acanthodians in biostratigraphy and as indicators of environmental settings, their use in biogeography was demonstrated. Although many of the acanthodian taxa are endemic, several are also found in other regions. The Silurian to earliest Devonian faunas of eastern Australia are most closely related to coeval Chinese assemblages. Several latest Silurian-earliest Devonian taxa are also recorded from the circum-Arctic region. The late Lochkovian to early Emsian assemblages, particularly from south-eastern Australia, have many taxa in common with Chinese faunas. The mid-Emsian taxa show highest endemicity; and the latest Emsian-Eifelian assemblages have the most cosmopolitan aspect. Acanthodian faunas become rarer and depauperate in the Middle Devonian, particularly in the south-eastern corner, and are mostly in poorly dated, ?fluviatile/marginal marine deposits. This study of acanthodian faunas has encompassed a full scale systematic review of the group in this region, an appraisal of phylogenetic relationships within the group and with other early vertebrates, their palaeoecology, and their use in biostratigraphy and biogeography.