82 resultados para Estuaries - Victoria, Western


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Historically, collecting nearshore habitat information has been problematic. Existing methods, such as aerial and satellite image interpretation are limited due to the attenuation of light in the water column obscuring the seabed structure. The advent of airborne bathymetric LiDAR (Light Detection and Ranging) systems (laser scanning of the seabed) now provides high-resolution seabed ‘images’ in areas that were previously difficult to survey. LiDAR imagery is available for the entire coastline of Victoria, Australia to depths of around 25 m, after being initially collected for climate change modelling by the Future Coasts Program (http://www.climatechange.vic.gov.au/adapting-to-climate-change/future-coasts). This dataset has provided the opportunity to test its applicability to inform fisheries management. Detailed geophysical information combined with spatially explicit AbTrack GPS located fisheries records and targeted genetic sampling is used in this study to provide a better understanding of the extent of available fishing grounds, direction of fishing effort and stock population structure within the Victorian western zone abalone fishery.
The species distribution modelling technique MaxEnt was used to produce a potential habitat suitability map for abalone in an attempt to capture the effective footprint of the  fishery. Also, by interrogating the spatially defined effort localities, we demonstrate an approach that may be used to identify areas where fishing effort is concentrated, and how this parameter changes temporally.
Despite barriers to adult dispersal (soft sediment barriers between reef patches), the genetic study indicates that larval movement is able to homogenize the gene pool over  large geographic distances. The western, central and eastern zone abalone stocks in Victoria were found to be a single large panmictic unit. This indicates high levels of stock connectivity and no obvious impacts of Abalone Viral Ganglioneuritis (AVG) on the genetic health of western zone stocks. We used detailed seafloor structure information interpreted from LiDAR to inform a replicated hierarchical fine scale genetic sampling design. We demonstrated that there may be extensive migration among abalone stocks across the Victorian abalone fishery.
This is contrary to previous studies that suggest recruitment is highly localised. In combination, these findings provide a valuable insight into the biology of H. rubra and immediate benefits for fisheries management. We discuss these results in the context of predicting resilience and adaptive potential of H. rubra stocks to environmental pressures and the spread of heritable diseases.
Adoption pathways are also provided to benefit future stock augmentation activities to catalyse the recovery of AVG affected reef codes. As larval dispersal is likely to be spatially and temporally variable, some AVG affected stocks are likely to recover through natural recruitment, while others will benefit from augmentation activities to ‘kick-start’ stock recovery. Evidence of neutral genetic homogeneity across Victorian reef codes suggests that the relocation of animals is unlikely to have significant genetic risks; however the potential for locally adaptive genetic differences may exist, and should be taken into consideration in future stock augmentation planning.
When combined, the spatial and genetic analyses provide valuable insights into stock productivity within the western zone fishery. Reefs appear to be expansive and support much available habitat, and the movement of larvae among reef structures is likely to be extensive in this region. Consequently, we propose that colonisation success and productivity is likely to be driven by ecological factors such as resources and/or competition, or physical factors such as wave exposure.

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Australian states and territories have legislation mandating reporting of cancer diagnoses; however, tumour stage at diagnosis, treatment plan and associated outcomes are not routinely recorded in cancer registries for all tumour types. This study describes the Evaluation of Cancer Outcomes study that collects detailed information for patients diagnosed with cancer in south-western Victoria.

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Riparian ecosystems are among the most degraded systems in the landscape,and there has been substantial investment in their restoration. Consequently, monitoring restoration interventions offers opportunities to further develop the science of riparian restoration, particularly how to move from small-scale implementation to a broader landscape scale. Here, we report on a broad range of riparian revegetation projects in two regions of south-western Victoria, the Corangamite and Glenelg-Hopkins Catchment Management Areas. The objectives of restoration interventions in these regions have been stated quite broadly, for example, to reinstate terrestrial habitat and biodiversity, control erosion and improve water quality. This study reports on tree and shrub composition, structure and recruitment after restoration works compared with remnant vegetation found regionally. Within each catchment, a total of 57 sites from six subcatchments were identified, representing three age-classes: <4, 4–8 and >8–12 years after treatment, as well as untreated (control) sites. Treatments comprised fencing to exclude stock, spraying or slashing to reduce weed cover, followed by planting with tube stock. Across the six subcatchments, 12 reference (remnant) sites were used to provide a benchmark for species richness, structural and recruitment characteristics and to aid interpretation of the effects of the restoration intervention. Vegetation structure was well developed in the treated sites by 4–8 years after treatment. However, structural complexity was higher at remnant sites than at treated or untreated sites due to a higher richness of small shrubs. Tree and shrub recruitment occurred in all remnant sites and at 64% of sites treated >4 years ago. Most seedling recruitment at treatment sites was by Acacia spp. This assessment provides data on species richness, structure and recruitment characteristics following restoration interventions. Data from this study will contribute to longitudinal studies of vegetation processes in riparian landscapes of south-western Victoria.

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OBJECTIVE: This paper aims to describe cancer survival and examine association between survival and socio-demographic characteristics across Barwon South-Western region (BSWR) in Victoria, Australia. DESIGN: This study is based on the retrospective cohort database of patients accessing oncology services across BSWR. SETTING: Six rural and three urban hospital settings across the BSWR. PARTICIPANTS: The participants were patients who were diagnosed with cancer in 2009. MAIN OUTCOME MEASURES: Overall survival (OS) of participants was the main outcome measure. RESULTS: Total of 1778 eligible patients had four-year OS for all cancers combined of 59.7% (95% CI, 57.4-62.0). Improved OS was observed for patients in the upper socio-economic tertile (64.2%; 95% CI, 60.9-67.5) compared to the middle (59.3%; 95% CI, 55.5-63.1) and lowest tertiles (49.6%; 95% CI, 44.2-54.9) (P < 0.01). On multivariate analyses, higher socio-economic status remained a significant predictor of OS adjusting for gender, remoteness and age (HR [hazard ratio] 0.81; 95% CI 0.74-0.89; P < 0.01). Remoteness was significantly associated with improved OS after adjusting for age, gender and socio-economic status (HR 0.86; 95% CI, 0.77-0.97; P = 0.01). Older age ≥70 years compared to <70 years conferred inferior OS (HR 3.08; 95% CI, 2.64-3.59; P < 0.01). CONCLUSIONS: Our study confirmed improved survival outcomes for patients of higher socio-economic status and younger age. Future research to explain the unexpected survival benefit in patients who lived in more remote areas should examine factors including the correlation between geographical residence and eventual treatment facility as well as compare the BSWR care model to other regions' approaches.

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This research explored spatial and temporal variability in the relationships between land cover, topography, and climate on streamflows and wetland extents in western Victoria.

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Background : An increasing burden of chronic disease and associated health service delivery is expected due to the ageing Australian population. Injuries also affect health and wellbeing and have a long-term impact on health service utilisation. There is a lack of comprehensive data on disease and injury in rural and regional areas of Australia. The aim of the Ageing, Chronic Disease and Injury study is to compile data from various sources to better describe the patterns of chronic disease and injury across western Victoria.

Design : Ecological study.

Methods
: Information on demographics, socioeconomic indicators and lifestyle factors are obtained from health surveys and government departments. Data concerning chronic diseases and injuries will be sourced from various registers, health and emergency services, local community health centres and administrative databases and compiled to generate profiles for the study region and for sub-populations within the region.

Expected impact for public health:
This information is vital to establish current and projected population needs to inform policy and improve targeted health services delivery, care transition needs and infrastructure development. This study provides a model that can be replicated in other geographical settings.

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Issue addressed: Health programs have been part of the responsibility of Victorian school education for 90 years. Yet rarely have there been studies to identify what is happening in school health promotion, or what the differences between schools might be, particularly in relation to the socioeconomic status of the school community and whether the school is in a metropolitan or regional area. Methods: In 1997 all Victorian schools (primary and secondary) in the State, Catholic and Independent systems were sent questionnaires in order to promote broader awareness about health promotion, and to identify what health programs, policies and activities the schools believed existed within their school community. A response rate of 43% was achieved, and results were collated under the six domains of the Health Promoting School model as outlined by the Western Pacific Regional Office of the World Health Organisation. Data analysed in this paper compared highest versus lowest quartiles for socioeconomic status (SES), and schools in metropolitan Melbourne versus regional areas. Results: Most differences between schools based on socioeconomic status occurred in secondary schools and were related mainly to environmental policies and practices, use of back packs, the presence of safety policies, involvement of parents in school activities and the provision of services for mental and social health needs. All differences were in favour of the highest SES quartile schools. Environmental policies and procedures, and school-based health and welfare services were present more often in metropolitan schools than in regional and rural schools. Conclusion: Although there were notable differences between schools, the audit results pointed to more similarities than differences between schools in the highest and lowest SES quartiles for health-related policies and practices; there were even fewer differences between metropolitan and non-metropolitan schools. So what: Regardless of the actual advantages and disadvantages schools experience with respect to location or socioeconomic status, it is important to understand that school staff perceive that they can and do have reasonably comprehensive health policies, procedures and practices to address health issues. Nevertheless, clear differences between schools did emerge in certain health areas and findings will assist policy making and the allocation of limited resources.

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The population genetic structure of snapper, Pagrus auratus (Bloch and Schneider), in Victoria was investigated using six polymorphic allozyme loci. Fish were sampled from four sites in Victoria and single locations in South Australia, Western Australia and New Zealand. Although there were distinct genetic differences between the snapper populations from each of the Australian states and New Zealand, only minor and largely insignificant differences were detected among Victorian populations. The results are consistent with previous genetic and tagging studies that indicate no mixing between snapper stocks in Victoria and Spencer Gulf in South Australia. This justifies separate management of the snapper fisheries in these regions. The low levels of polymorphism and heterozygosity in Victorian snapper suggest an isolation by distance model of population structure rather than one of discrete subpopulations.

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The link between volunteerism and social capital has received some attention in Australia in recent years. Of particular note to this paper is the work of Baum, Bush, Modra, Murray, Cox, Alexander, and Potter (2000), who described the contribution volunteers made to social capital in a metropolitan setting - the western suburbs of Adelaide, South Australia. The aim of this current study is twofold, to describe the contribution volunteers make to social capital through participation, reciprocity and social trust in a regional and rural setting; and to compare findings with those relating to a metropolitan environment. In the light of differing volunteer patterns in rural and regional environments compared to metropolitan environments, we hypothesised that the relationship between volunteerism and indicators of social capital would also be different. The results from this study support the findings of Baum, Modra, Bush, Cox, Cooke, and Potter (1999) and therefore reinforce the premise that volunteers make a substantial. contribution to social capital. While greater numbers of people who live in rural or regional areas undertake volunteer work, we found there are more similarities between the rural/regional and metropolitan sectors regarding volunteerism than there are differences.

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Intertidal invertebrates are under pressure from both direct and indirect threats, the most serious being from over-exploitation, habitat loss and alteration, decline in water quality, introduced species and pathogens, and global warming. This article explores the current protective mechanisms in place that provide some protection to intertidal invertebrates in Victoria and looks at a case study of Western Port, Victoria. The results of the case study indicated a general consensus that intertidal invertebrates are not adequately protected in Victoria. The recommended actions to ensure adequate protection in the future are an amendment to current legislation, increased education and greater law enforcement, and further implementation of the concept of integrated coastal zone management.

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The dietary importance of prey of estuary perch (Macquaria colonorum; Percicthyidae: Günther) was examined spatially, temporally and among size classes. Fish were collected from the Hopkins River, south-western Victoria, from September 1998 to February 1999. The species is a euryhaline, euryphagic carnivore with spatial, temporal and size class variations in diets. Fish caught from estuarine locations consumed primarily Paratya australiensis (40% IRI) while freshwater fish consumed mostly Tricopteran larvae (63.5% IRI). In both freshwater and estuarine locations, the relative importance of P. australiensis decreased with increasing length of fish. Diet changed seasonally, indicating opportunistic changes in prey. The species selected particular prey items relative to environmental availability (P. australiensis, Amarinus lacustrine).

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The infaunal bivalve Soletellina alba is susceptible to mass mortalities during annual winter flooding in the Hopkins River Estuary, southern Australia. Periods of low salinity (≤1) are the likely cause of these mass mortality events, which can occur in seasonally-closed estuaries when high winter flows are sufficient to flush all salt water from the estuary. Core samples of S. alba were collected from two water depths across four times and at three sites near the mouth of the estuary. Minimal to zero abundances of large S. alba (>1 mm) were expected to be sampled, particularly at the shallower water depth, during a typical winter flood event. However, the present study occurred during a period of drought, which led to the absence of winter flooding. This absence of winter flooding prevented the occurrence of lethal salinities (i.e. ≤1) in the estuary during this period and a greater number of living S. alba adults were sampled. Abundances of juvenile and adult S. alba were still variable, even in the absence of winter flooding, and reflected an interaction between date, site and water depth. However, no mass mortalities of adults were observed during the drought conditions in contrast to what occurs during typical winter flood events and provides support for the hypothesis that winter flooding is responsible for past mass mortalities.

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The study assessed the anthropometric status of 337 sub-Saharan African children aged between 3-12 years who migrated to Australia. These children were selected using a snowball sampling method stratified by age, gender and region of origin. The prevalence rates for overweight and obesity were 18.4% (95%CI: 14 - 23%) and 8.6% (95%CI: 6% -12%) respectively. The prevalence rates for the indicators of undernutrition were: wasting 4.3% (95%CI: 1.6%-9.1%), underweight 1.2% (95%CI: 0.3%-3.0%), and stunting 0.3 (95%CI: 0.0%-1.6%). Higher prevalence of overweight/obesity was associated with lower household income level, fewer siblings, lower birth weight, western African background, and single parent households (after controlling for demographic and socio-economic factors). Higher prevalence rates for underweight and wasting were associated with lower household income and shorter lengths of stay in Australia respectively. No effect was found for child's age, gender, parental education and occupation for both obesity and undernutrition indices. In conclusion, obesity and overweight are very prevalent in SSA migrant children and undernutrition, especially wasting, was also not uncommon in this target group.