Academic literature on the topic 'Population biology – Western Australia – Perth'

Abstract Background There has been concern that patients with malignant disease from remote and regional country areas may have adverse outcomes compared with those from cities. Western Australia (WA) with an area of 2,526,786 square kilometers, is one third the size of Australia. It has a population of 2.6 million of which 92% live in the capital city Perth and the southwest corner. In WA, multiple myeloma is managed in tertiary public hospitals and private physician practice located in Perth. While oral based immunomodulators and alkylators are readily delivered in the regional areas, patients travel to Perth for parenteral chemotherapy and stem cell transplantation. The WA state government subsidizes transport and accommodation for patients from regional areas to travel to Perth for treatment and clinical review via the Patient Assisted Travel Scheme (PATS). Telehealth through video conferencing is also used for review of patients on oral-based anti-myeloma treatment or during surveillance periods to avoid expensive and time-consuming travel to Perth. The Royal Flying Doctor Service (RFDS), a non-profit medical organization, provides prompt transfer of unwell patients from regional and remote areas of WA to Perth. Pathology services in remote regions are provided by the publicly funded PathWest organization. Method We retrospectively reviewed the survival outcomes of patients with multiple myeloma in the WA public healthcare system. Patients diagnosed between 2008 to 2017 were included (n=569). Staging information was extracted from the laboratory information system and the cytogenetic database in PathWest. Patient demographics, complications requiring admission, mortality and follow-up data were extracted from the public hospital patient management systems. Patients were segregated into regional or metropolitan by their residential address postcodes. Patients diagnosed and/or followed-up in the private sector were excluded. Survival was analyzed by Kaplan-Meier curves, Log-rank test and Cox proportional hazards model. Result Median age at diagnosis was 67 years old (range 29 to 98), with 56% above 65 years. 56% were males, 44% were females. Overall median survival was 46 months (95%CI:41,52). 1-year, 3-years and 5-years survival rates were 80%, 56% and 30% respectively. 25% (n=143) of patients resided in regional areas. No statistically significant difference in overall survival time between patients from metropolitan and regional areas was identified (p=0.2): 47 months (95% CI:43,54) and 42 months (95% CI: 33,54) respectively. Subgroup analysis also did not find any significant difference in overall survival of each R-ISS staging between metropolitan and regional areas. Discussion This retrospective study provides real-life survival data of of an Australian-based population in a state with a large land mass and low population density outside the capital city. The overall survival of patients living in regional areas was not significantly different from those living in the capital city. This gives credence to the benefit of the WA government supported regional network of travel, accommodation and Telehealth conferencing overcoming the distance barrier in the provision of comprehensive medical care in the management of a hematological malignancy. Figure. Figure. Disclosures No relevant conflicts of interest to declare.

The Australian sea-lion, Neophoca cinerea, has a 17-18-month breeding cycle on islands off the west coast of Western Australia. Buller, North Fisherman and Beagle Is are the main pupping sites, with several very small colonies (n> 3) at the Abrolhos Is. The 4-5-month pupping seasons are synchronised at North Fisherman and Beagle Is, but the sea-lions from Buller I. breed one month later and those from the Abrolhos Is two months earlier. Pup production and pup mortality were highly variable between seasons over which observations were recorded: 129 pups were born at the main breeding sites in early 1988, the mortality in the first five months was 7.1%, whereas 181 pups were born in late 1989 of which 24.3% died. Pups remain in the vicinity of their natal islands for the first 4-5 months of life before leaving, perhaps on foraging trips, with their mothers. Most return to their natal island, although others haulout on islands up to 27 km away. Some male N. cinerea congregate in bachelor colonies on islands adjacent to the Perth metropolitan region during the non-breeding season and migrate up to 280 km north each breeding season. The status of the isolated, west-coast N. cinerea population is unknown. The current high level of human pressure on sea-lion terrestrial habitats and their food resources indicate a need for further monitoring of this species.

Background:There is sparse population-level data on outcome in patients with Immunoglobulin-A vasculitis (IgAV) and none from AustraliaObjectives:We compared long-term mortality for paediatric and adult IgAV patients with age- and gender-matched controls.Methods:Linked health data for pediatric (<20 years=473) and adult (20+ years, n=267) IgAV patients were obtained from state-wide hospital and deaths registries in Western Australia for the period 1980-2015. All-cause mortality rates (MR) (deaths/1000 person-years) were compared with controls using mortality rate ratios (MRR) and with the general population of Western Australia by standardised mortality rate ratios (SMRR) with Poisson derived 95% confidence intervals (CI). We used Kaplan-Meier survival estimates and multivariate Cox regression derived hazard ratios (HR) for time dependent analyses.Results:In pediatric patients (mean age 7.2 years, 60 % male) MRR was 1.27 (CI: 0.34-4.08, p=0.68) and SMRR was 2.31 (CI: 0.72-5.7, p=0.47) (Table 1) with a 20-year survival rate (>99%) similar to controls. Despite higher rates of renal failure (1.5% vs 0.2%, p=0.002) deaths in pediatric IgAV patients were mainly from unrelated causes. In adult IgAV patients (mean age 55.8 years, 48% males) MMR was 2.06 (CI 1.70-2.50, p<0.01) and SMRR 6.16 (3.04 -14.3, p<0.01) (Table) during a mean of 19.5 years follow-up with significantly reduced survival at five (72.7 vs. 89.7 %) and twenty years (45.2% vs. 65.6 %) (p<0.05). Renal disease (HR: 1.47, CI 1.04 - 2.06), the presence of any comorbidity (HR:1.30, CI 1.23 - 1.37) and male gender (HR:1.23; CI 1.04 - 1.47) were independent predictors of death. While cardiovascular events (34.2%) and malignancy (19.4%) were the most frequent causes of death, only death from infections (5.8 vs 1.8%, p=0.02) and renal disease (3.6 vs 1.8%, p=0.03) were more frequent in adult IgAV patients than controls.Mortality data for childhood and adult-onset IgAV patients and controls. Figures indicate mean (±SD), numbers (%) or rate/1000 patient months (95% CI)PediatricAdultIgAVControlsP valueIgAVControlsPMean follow-up (yrs)22.71 (±5.2)23.75 (±3.17)0.00111.9 (±9.04)15.94 (±8.30)0.001Non-survivors (%)<5 (0.8)9 (0.9)0.5137 (51.3)394 (33.4)<0.001Person-years1027529520317818815MR0.39 (0.1, 0.9)0.30 (0.1, 0.5)43.11 (36,1,50.9)20.94 (18.9, 23.1)MRR1.27 (0.34, 4.08)0.672.06 (1.70, 2.50)<0.001SMRR2.31 (0.71, 5.71)0.716.16 (3.04, 14.3)<0.001Conclusion:Compared to controls and general population, mortality risk was not increased in paediatric IgAV patients for at least 20 years following diagnosis despite a higher rate of end stage renal failure. However, in adult IgAV patients, all-cause mortality risk was six times higher than in the general population leading to significantly reduced five-year survival, especially for male patients with comorbidity including renal disease.Acknowledgments:The authors thank the Data Custodians of the Hospital Morbidity Data Collection (HMDC), Emergency Department Data Collection (EDDC), the Western Australian Cancer Registry (WACR), the State Registry of Births, Deaths and Marriages, the WA Electoral Commission, and the NCIS for use of the CODURF dataset, and the staff at Data Linkage Branch at the Western Australian Department of Health for their assistance in provision of data. This work was supported by an unrestricted grant from the Arthritis Foundation of Western Australia. Author WDR received a PhD Scholarship in Memory of John Donald Stewart from the Arthritis Foundation of Western Australia.Disclosure of Interests:Johannes (“Hans”) Nossent Speakers bureau: Janssen, Milica Ognjenovic: None declared, warren raymond: None declared, Helen Keen Speakers bureau: Pfizer Austrlaia, Abbvie Australia, Charles Inderjeeth Consultant of: Linear Research Perth, David Preen: None declared

Background:Survival in ANCA-associated vasculitis (AAV) has improved substantially in the last fifty years, but Australian data and studies with a control population are scarce.Objectives:The aim of this study was to compare the all-cause mortality rate between patients with AAV and matched controls in Western Australia.Methods:A retrospective population-based cohort study conducted using the Western Australia Health Data Linkage System (WADLS) for patients with a diagnostic code for AAV (International Classification of Diseases (ICD)-10-AM M30.1, M31.3 and M31.7). We included 240 patients with AAV (mean age 57.37 ± 16.69, 48.8% males) who had a hospital admission or emergency department visit between 1 January 2000 and 31 December 2014 and 4406 controls matched for age and sex. Death details were obtained from the WA Death registry. Mortality rates per 1000 person-years (MR) for AAV patients and controls were compared by mortality rate ratios (MRRs) with 95% CI. Kaplan Meijer survival estimates were analyzed by log-rank test.Results:During a mean follow-up of 6.58 years (3.37, 11.25) 83 incident AAV patients (34.6%) died, giving a mortality rate of 48.13 per 1000 person-years (95% CI 38.33, 59.66). This was 82% higher overall than in controls (MRR 1.82, 95% CI 1.46, 2.26, P < 0.0001), while the MRR for males with AAV was 2.28 (95% CI 1.46, 2.26; P < 0.0001) and for females 1.43 (95% CI 1.01, 2.02; P = 0.0267). Survival estimates at one (90.5%) and five years (75%) were significantly lower in AAV patients than controls.Conclusion:Over the last fifteen years, the mortality risk for AAV patients remains significantly increased compared with matched controls and more so for male than female AAV patients. Together with the reduced one- and five-year survival rate, this indicates the need for further improvements in initial disease management in order to reduce the risk of death in AAV.TableMortality rates (MR) per 100 patient years and Mortality rate ratio (MRR) with 95% CI in patients with AAV and controlsAAVControlDeathsPersonyearsMR(95% CI)DeathsPersonyearsMR(95% CI)MRR(95% CI)All83172448.1(38.3, 59.6)12194606926.4(25.0, 27.9)1.82 (1.46, 2.26)Male4978962.1(45.9 82.0)6902529528.2(25.2, 29.3)2.28 (1.72, 3.02)Female3493536.3(25.1, 50.7)5292077325.4 (23.3, 27.7)1.43 (1.01, 2.02)Figure.Kaplan Meyer Survival curves for AAV patients and controlsAcknowledgments:The authors thank the Data Custodians of the Hospital Morbidity Data Collection (HMDC), Emergency Department Data Collection (EDDC), the State Registry of Births, Deaths and Marriages, the WA Electoral Commission, and the staff at Data Linkage Branch at the Western Australian Department of Health for their assistance in provision of data. This work was supported by an unrestricted grant from the Arthritis Foundation of Western Australia. Author WDR received a PhD Scholarship in Memory of John Donald Stewart from the Arthritis Foundation of Western AustraliaDisclosure of Interests:Wade Taylor: None declared, warren raymond: None declared, Helen Keen Speakers bureau: Pfizer Austrlaia, Abbvie Australia, Charles Inderjeeth Consultant of: Linear Research Perth, David Preen: None declared, Johannes (“Hans”) Nossent Speakers bureau: Janssen

Introduction: Australia's largest state, Western Australia (WA), comprises a land area of more than 2.5 million square kilometres, an area than larger than that of Texas and Alaska in the United States combined, with a population of more than 2.6 million. Whilst a large proportion of Western Australians live in the capital city Perth, approximately 20% are dispersed across the state in regional and remote areas. The diagnosis and treatment of myeloma require specialist Haematologist management and frequent follow-up. Access to Haematology specialist services and treatment in WA is centred in metropolitan Perth, with outreach services visiting regional and remote areas limited in location and frequency. Some patients are required to travel long distances or relocate to access treatment. The aim of our study was to assess difference in clinical presentation, treatment and outcomes of myeloma patients living in regional or remote Western Australia compared to metropolitan Perth. Methods: A retrospective chart review of new cases of symptomatic multiple myeloma diagnosed between January 2008 and December 2019 and referred to Royal Perth Hospital and Fiona Stanley Hospital, two tertiary metropolitan hospitals was conducted. Data was obtained regarding patient demographics, disease characteristics, treatment, response and survival outcomes, through review of patient paper and electronic medical records. Patients were grouped into those living inside or outside the Perth metropolitan area (metro or non-metro) according to area codes obtained from the WA government data suite. Results: Two hundred and seventy-five cases were identified, 218 (79%) metro and 57 (21%) non-metro. Baseline characteristics for the two groups are listed in Table 1. The median age at diagnosis was 68.4 years (range 30-91.5 years) and 47% were female, with no significant difference between the groups. There were a higher number of patients with lytic bone disease at diagnosis in the non-metro cohort (75.4% non-metro vs 60.2% metro, p=0.03) as well as a higher proportion of patients with international staging system (ISS) stage II or III disease (77.8% non-metro vs 55.8% metro, p=0.005). Sixty three percent of patients overall received first line bortezomib based therapy and 27% first line imid based therapy, with no significant difference by location. Overall 41% of patients underwent autologous stem cell transplantation, 70% of those ≤70 years of age, with no significant difference between the groups (33.3% non-metro vs 42.5% metro, p=0.21). The median overall survival (OS) was 47 months for the entire cohort. Survival was lower in the non-metro cohort, although this did not reach statistical significance (median OS 52 months for metro vs 40 months for non-metro, p=0.05) Figure 1. Progression free survival (PFS) was similar between the two groups (median PFS 23 months metro vs 12 months non-metro, p=0.12) Figure 2. Early mortality at 6 and 12 months was higher in the non-metro cohort (Six-month mortality was 21.1% non-metro vs 8.3% metro, p=0.01. Twelve-month mortality was 28.1% non-metro vs 13.4% metro, p=0.01) Figure 3. There was a trend in cause of early mortality due to infection being higher in the metro cohort, and cause of early mortality due to renal failure being higher in the non-metro cohort, Table 1. Conclusions: In our cohort, patients living in non-metropolitan locations were more likely to present with higher ISS stage and lytic lesions at diagnosis. Rates of early mortality were significantly higher in the non-metropolitan cohort. There was a trend towards shorter overall survival although this did not meet statistical significance. These differences may represent delays in clinical presentation and diagnostic workup and highlight the need for optimisation of follow up of patients in non-metropolitan areas particularly during the early time period post diagnosis. Periods of resource constraint and travel restrictions as is faced currently may accentuate these disparities. In addition, the nature of myeloma therapy is evolving with addition of treatments requiring expertise to deliver, such as monoclonal antibodies and chimeric antigen receptor T cells. As these therapies become commercial further studies are needed to assess adequacy of access for patients from non-metropolitan centres. Disclosures Leahy: Pfizer: Membership on an entity's Board of Directors or advisory committees. Sidiqi:Celgene: Honoraria, Other: Travel grant; Amgen: Honoraria; Janssen: Honoraria.

Little is known of the breeding behaviour of the Forest Red-tailed Black Cockatoo Calyptorhynchus banksii naso (FRTBC), a large, iconic forest cockatoo, endemic to the south-west corner of Western Australia, currently listed as Vulnerable under the State Western Australian Wildlife Conservation Act and under the Commonwealth Environment Protection and Biodiversity Conservation Act. In this paper, we provide details of breeding behaviour of FRTBC based on observations throughout the year over 17 years, together with observations of diet and feeding behaviour over the same period. FRTBC are monogamous hollow-nesters. Breeding was recorded in all months, with peaks in autumn-winter (April– June) and spring (August–October), with few records in January and February. Breeding also varied between years, with little breeding in 1999, 2001 and 2008, but many observations in 2006 and 2009. Breeding occurred at times of fruiting of either of the principal feed trees, Jarrah Eucalyptus marginata or Marri Corymbia calophylla, so it does not depend solely on one or the other of these species. Courtship displays were noted at all times of the day, from before dawn at roost sites to dusk. In total, 205 breeding events were recorded, of which 69 (93%) of 72 nests had breeding confirmed on a second visit. Use of particular nest hollows varied considerably, with some used only once and some up to seven times. Only one egg is laid, which the female incubates for 29 to 31 days, before a nestling hatches weighing between 27 and 32 g. The female remains in the hollow during incubation and only leaves for a short period in the evening to be fed by the male, usually at dusk. The chicks are brooded for up to 10 days, after which the female leaves the nest between dawn and dusk. Pairs of birds appear to recognise each other by calls, not responding to calls by others in the area. Chicks only respond when the parent is heard. Chicks are fully feathered at 48 days. Fledgling success was estimated at 60%. Juveniles remain dependent on the adults 18 months to 2 years. Thirty-seven chicks were banded between 1997 and 2011. Juvenile-immature birds moved on average less than 3 km from their natal tree and older birds were observed moving up to 19 km. This suggests that FRTBC are generally sedentary. Immature birds took up to three times as long as their parents to open Jarrah or Marri nuts and eat the seeds. In recent years there has been an interesting change in foraging behaviour of birds in the northern Darling Range (adjacent to the Perth metropolitan area) with the FRTBC discovering and using a new food source, the introduced Cape Lilac Melia azedarach, and this species is of growing importance as food in the Perth region. In combination, the data on breeding biology and diet highlight the importance of identifying recruitment rates and food availability in managing populations of FRTBC.

e14000 Background: Indigenous women with breast cancer (BrCa) have higher mortality than Non-Indigenous women. Remoteness, aggressive tumour biology, treatment acceptance and compliance are all contributory factors. A retrospective study of geriatric indigenous women (aged 55 years more) with BrCa has shown high co-morbidity and treatment-related toxicity scores translating to high mortality comparing to the non-indigenous geriatric population (aged 65 years or more). An algorithm allowing prediction of risk of morbidity and mortality to enable optimisation of care for this patient group, catering to needs, values, beliefs and resources of geriatric Indigenous patients is warranted. Methods: To create a predictive algorithm and model of care based on the demographics, social environment, biology, co-morbidity burden and predicted chemotherapy toxicity scores of Indigenous women with BrCa to then be applied to a validatory prospective study.A cohort of 132 indigenous geriatric patients was identified from the Western Australian Cancer Registry from 2001 to 2010 along with remoteness matched geriatric non-Indigenous women in a 1:1 ratio. Data was collated on cancer biology, chemotherapy toxicity, mortality, co-morbidity burden (by the Charlson Co-Morbidity Index -CCI) and predicted chemotherapy toxicity (by CARG toxicity score). An algorithm was created based on these factors to identify patients at greatest risk of morbidity and mortality. Results: Elements identified as predicting morbidity and mortality were; remoteness based on distance from Perth (scored 0-3), lymph node status (scored 0-1), social isolation (scored 0-1), the Carg score (scored 0-3), and the CCI (scored 0-4). The KR Geri-Indigenous Rx Model was created using these components and scored out of 12. Conclusions: The score has been used to create three risk categories, low (1-3) intermediate (4-8) and high risk (9-12). A model of care was designed with staged increases in service elements and intensity for increasing risk category. These include the addition of Indigenous health worker review initially in clinic as well as at home during chemotherapy, initial geriatric assessment and potential geriatrician review, optimization of co-morbidities and medications, consideration of dose adjustments, social worker visits to increase services, increased surveillance, with telehealth contact and GP update with treatment planning as well as on treatment completion. A prospective study based on this model is planned.

The reproductive biology, age, growth, food and habitat of Nannoperca australis are described from samples collected from fringing macrophyte beds of the Macquarie River, Tasmania. Comparisons are made with the same species at Narrandera in New South Wales and other nannopercids, mainly in south-western Australia. Nannoperca australis spawned at the end of its first year, predominantly between October and December, inclusive. The peak mean gonadosomatic index of males occurred in August at 8.0 and that of females two months later at 11.5. The largest oocytes, of running-ripe females collected in October and December, were 1.15 mm in diameter. Fecundities ranged from 78 for a 1-year-old 37-mm fish to 679 for a 2-year-old 63-mm fish. Spawning is presumed to occur in the macrophyte habitat, since adults did not emigrate from these areas at this time. Otoliths and length-frequency histograms indicated that populations were dominated by 0+ fish. Amphipods and ostracods predominated in the guts of N. australis and prey items were mostly either benthic invertebrates or plant epifauna. Plankton was consumed by small fish in greater quantities than by larger fish, whereas the opposite was true for benthic and epifaunal prey. Fish were virtually always associated with aquatic macrophytes and almost always with shallow, still water.

Purpose“Asian” is an aggregating descriptive term commonly used in Australian media, politics and everyday speech to describe people of diverse backgrounds. The purpose of this paper is to question the extent to which “Asian” Australian residents living in Perth, Western Australia demonstrate spatial or organisational panethnic association.Design/methodology/approachThe paper analyses quantitative population data from the 2011 Census using GIS to visualise the spatial residential distribution of individuals born in Asian countries and individuals with Chinese ancestry within the Perth metropolitan area. The paper further uses qualitative data drawn from fieldwork conducted in Perth to consider evidence of organisational panethnic association.FindingsFor first generation migrants there is currently little spatial or organisation evidence of “Asian” panethnic association in Perth. Migrants from different ethno-national backgrounds exhibit very different residential patterns. Incipient ethnoburbs are developing that appear to be based on ethnicity rather than panethnicity. Migrant organisation in Perth is likewise arranged primarily on the basis of ethnicity although some panethnic work is observed.Research limitations/implicationsFindings indicate trends towards ethnic residential segregation. Further longitudinal research could expand upon these findings. Qualitative research could determine causes of segregation and implications of (pan)ethnic identities, and explore how individuals from Asian countries respond to the dominant linguistic aggregation of “Asians”.Originality/valueThis paper offers an original analysis of a common frame of reference that has received little critical attention in the Australian context. It applies the framework of Asian panethnicity developed in the USA and finds it wanting, highlighting an inconsistency between the racialised language used in Australia to describe migrants from Asia and the ways these migrants associate.

The Roe’s abalone (Haliotis roei) fishery near Perth, Western Australia, is uniquely accessible, and highly vulnerable to overexploitation. The sustainability of this intensively utilized fishery requires robust assessment. To facilitate an assessment, this research aimed to provide rigorous and detailed biological information with appropriate interpretation. Four critical aspects of the species’ biology and population dynamics were investigated: (1) the stock structure; (2) the recreational catch; (3) an appropriate growth curve and description of size at age; and (4) abundance measures against which to assess the impact of fishing mortality. Allozyme electrophoresis was used to investigate stock structure across the species’ distribution. Standardized variance in allelic frequencies between 10 sites in south-western Australia indicated high levels of gene flow across the 3000 km sampled (mean FST = 0.009). An isolation-by-distance was evident when pairwise measures of GST were related to geographic distance (r=0.45, P<0.001). The area of complete genetic mixing was estimated from samples within the Perth fishery to be less than the distance between the two nearest sites, or 13 km. Consequently, the Perth fishery comprises numerous discrete stocks, each requiring independent assessment. A possible mechanism for this population structure is the retention of larvae in the wind driven currents oscillating in the near-shore lagoons, with rare pulses of long distance dispersal via the southerly Leeuwin current, running further offshore. The presumed impact of intensive recreational fishing, combined with substantial commercial quotas for the Perth fishery, had led to tight restrictions on fishing effort, without any quantitative measure of the recreational catch. A stratified creel survey was adapted to estimate the effort, catch rate and mean weight of abalone harvested by the recreational sector. Catches were estimated for reef complexes, or stocks, of less than 10 nautical miles (18.5 km) of coast. Between 1997 and 2000 the recreational catch varied from 30 to 45 tonnes whole weight, approximately equivalent to the commercial quota of 36 tonnes. On average 88% of the recreational catch came from two stocks, while 98% of the commercial catch came from these two, and one additional, stocks. The incidental mortality from recreational fishing, measured as the number of abalone left dead on the reef as a proportion of the estimated catch, was approximately 7% and 20% at two sites surveyed. Spatial and temporal patterns of growth were examined on the west coast of Western Australia. Growth increments were measured for abalone larger than about 30 mm from tagging studies at five sites in the Perth fishery, a site at the northern extent of the species’ distribution and a site in the southwest. Mean annual growth increments of the 0+ year class were obtained by fitting components to length frequencies from five sites in the Perth fishery, and combined with growth increments from each Perth tag site for model fitting. A von Bertalanffy growth curve provided a slightly better fit to the tag data, but a Gompertz growth curve was a much better fit when the mean increment from the 0+ to 1+ cohort was included, with the inflection occurring at about 40 mm, the size at sexual maturity. There was no difference in annual growth between the two years studied. There was significant variation in growth between the reef platform and adjacent sub-tidal reef, but this variation was site specific and faster growth rates were not consistently associated with either habitat. There was no latitudinal trend in growth rate. Growth at the Perth sites was the fastest and similar at all five sites with growth increments greater in summer than in winter. Size and abundance of abalone were measured using fixed transects and quadrats. Abalone densities were highest on the outer edge of the platform, intermediate in the middle of the reef platform, and lowest on both the inner platform and the sub-tidal reef. The pattern of mean lengths of abalone was the inverse of the density. Mean length and abundance were driven by the presence of post-settlement juveniles on the outer and middle reef habitats. There was a high spatial variation in abundance, with densities varying between transects at the same site, but the trend between years for each transect at a site was not significantly different. Abalone abundances, by size class, were examined from sites sampled between 1996 and 2002. A low density of post-settlement juveniles at all sites in 1997 was reflected in low densities of the 1+ and 2+ year classes in subsequent years. Abalone abundances at an unfished site were steady over the seven years. Two sites were located within each of the main stocks utilised by the recreational fishery. Abundance was stable or increasing in one stock, corresponding to a stable total catch. In the second stock the total catch increased over time and abundances declined. Perth is the focus of the Roe’s abalone fishery, with recreational and commercial fishers take about equal shares of the annual catch. Stocks are highly subdivided, with most of this catch coming from only 3 stocks occupying about 20 nautical miles of coast. Growth rates were found to be lower than previous estimates, and more similar to other commercial species of abalone. All life history stages are highly habitat specific, particularly the recruits, and the distribution and abundance through time indicate that the main stocks are near, or slightly over, the limit of sustainable fishing.

[Truncated abstract] Managed Aquifer Recharge (MAR) is a technique that can be used to capture and store water in aquifers for later reuse. This method recycles water that would normally be lost or discarded to the environment. MAR has been observed to have the potential for improving the quality of recharged water through a combination of physical, chemical and biological processes. The aim of this study was to investigate the changes in groundwater microbial population structure during MAR and the major influences that drive these population changes. Biogeochemical MAR studies have the potential to assist in the improved prediction of the removal of contaminants such as nutrients, pathogens and trace organics from the recharged water. Biological clogging during recharge also has the potential to overwhelm an aquifers ability to process wastewater thus reducing the hydraulic conductivity of the aquifer. Therefore further research into the spatial and temporal biogeochemical processes that occur during MAR is required. The geochemical and microbial population dynamics of two contrasting MAR techniques were investigated at two different geographical locations (Perth, Western Australia and Adelaide, South Australia). These MAR sites contained aquifers of dissimilar properties that were recharged with wastewater that contrasted in water quality. The Perth MAR site received secondary treated effluent which continuously infiltrated the unsaturated zone into an unconfined aquifer aided by infiltration galleries. Reclaimed water was extracted from a well at distance from the infiltration gallery. ... Notably the background and recovered water was most dissimilar in microbial and chemical population structure to that described for the infiltration gallery and injection well. Microbial and chemical evidence suggested that the background and extraction well groundwater were unaffected by plume migration. These results suggested that extraction well groundwater was similar in quality to that of ambient groundwater. Significant geochemical and microbial changes of secondary treated effluent during infiltration and lateral movement through aquifer were implicated in addition to the forced hydraulic gradient created from extracting fives time the volume of infiltrating wastewater. This study demonstrated that microbial populations and the geochemical processes associated with MAR can be studied and compared. Multivariate statistical methodology greatly simplified a vast array of dynamic biogeochemical information that could be dissected for meaningful interpretation over distance and time. The study evaluated the major biogeochemical influences which resulted in microbial and geochemical changes where it was noted that microbial populations were more dynamic than geochemical variation over time. Additionally biogeochemical comparative analysis indicated that microbial populations could change in population structure before a shift in aquifer geochemistry was detected. It is anticipated that the results from this study will benefit further research into the biogeochemical processes involved in water quality changes (e.g. nutrient removal, pathogen decay and biodegradation of trace organics) as well as controlling biological clogging of MAR schemes.

[Truncated abstract] Amidst concern over the global phenomenon of declining amphibians, there is an increasing appreciation of the importance of understanding population dynamics at both local and regional scales. Data on the viability and persistence of species in landscapes altered by humans are scarce but an understanding of these dynamics is essential for enabling long-term species conservation in a modified world. Habitat loss, fragmentation and ensuing salinisation are of particular concern for species in Australia’s temperate agricultural regions where the rapid conversion of continuously vegetated landscapes to small fragments has occurred in less than 200 years. This thesis investigated the local and metapopulation structure of Heleioporus albopunctatus to determine the current population structure and likely future of this species in a highly degraded landscape: the wheat and sheep growing areas of southwestern Australia ... The life-history attributes of H. albopunctatus, including high fecundity, high adult longevity and low to moderate dispersal contribute to a robust regional metapopulation, responsive to changes, but with a strong chance of persistence over the long-term. H. albopunctatus appears to have adjusted to a radically modified landscape but its long-term persistence may be dependent on the existence of a small number of source populations that recruit in most years.

[Truncated abstract] In my study of Australonereis ehlersi and Simplisetia aequisetis [Polychaeta: Nereididae] from the Swan River Estuary, Western Australia, I assessed the life history, geographical population structure and production of both species, then measured their roles in microbial denitrification and nitrogen cycling within the sediments of the estuary. Both species exhibit a mean life-span of approximately 1 year, a production:biomass turnover rate of about 3 and potentially are capable of reproducing throughout the year, peaking during winter to spring. A. ehlersi exhibited a marine euryhaline distribution, occurring only in the main basin and lower estuary, typically at a very low density of adults; S. aequisetis exhibited a euryhaline distribution, occurring estuary-wide during both summer and winter. High density and biomass of A. ehlersi occurred in the middle estuary (at Como), predominantly as winter- recruiting juveniles. Gravid, atokous adults spawned pelagically, with a 2 to 4 month larval development period preceding settlement. Intolerance of freshwater by the pelagic larvae possibly is the major reason excluding specimens from the upper reaches of the Estuary. Adult S. aequisetis brood eggs and embryonic larvae in tubiculous burrows; the life-cycle presumably progresses entirely in sediments of relatively stable interstitial salinity (compared to pelagic fluctuations), enabling recruitment by larvae and adults into the upper reaches of the Estuary. ... The ammonification rate was higher for A. ehlersi than S. aequisetis-inhabited cores, and lowest in uninhabited cores where polychaete excretion was absent. In the absence of C2H2, sediments of S. aequisetis inhabited cores indicated a lower net NH4+ influx than uninhabited cores, whereas A. ehlersi inhabited cores exhibited a slight net efflux of NH4+ from the sediment. The difference in magnitude of nitrogenous fluxes imparted by the two polychaete species is hypothesised to relate to the influence of their respective habits on the composition and activity of their associated sedimentary microbial community. Juvenile S. aequisetis are hypothesised to homogenise and aerate sediment continually, enhancing microbial nitrification and retarding anaerobic denitrification. Permanent A. ehlersi burrows would facilitate vertical and radial oxic/anoxic stratification of sediment which, combined with enhanced substrate supply through burrow ventilation, resulted in increased rates of microbial denitrification and nitrification. I have proposed a preliminary framework by which guilds of benthic fauna, each with similar designated habits, may be tested for predictable bioturbative influence on nitrogen cycling, i.e. whether particular habits may be considered 'functional groups'. In conclusion, the fine-scale effects of A. ehlersi and S. aequisetis on microbial nitrogen cycling are integrated with details of broader-scale population dynamics to define the role of polychaetes in estuarine nitrogen cycling, with a view to managing eutrophication.

[Truncated abstract] The species-rich Southwest Australian Floristic Region (SAFR) is a global biodiversity hotspot. Characterised by a Mediterranean-type climate and nutrient deficient landscape, this region is endowed with 7380 native vascular plant species/sub species, of which 49% are endemic and 2500 are of conservation concern. Despite the global significance of this region, there is still only a poor understanding of the factors influencing high diversity and endemism, and especially the population genetic consequences of narrow endemism and naturally fragmented species distribution. Holly leaved banksia (Banksia ilicifolia R. Br.), although widespread through Southwest Western Australia (SWWA), has a naturally fragmented distribution, with generally small populations restricted to swales and wetland fringes with depth to groundwater less than 10 m. As such, it provides an excellent model to better understand the ecological genetic consequences of local endemism, population size and natural population fragmentation . . . Products of wide outcrossing (over 30 km) showed a heterosis effect over local outcrossing, indicating increased ecological amplitude of offspring following interpopulation mating. These results suggest that the breeding and mating biology of B. ilicifolia counters the negative genetic erosion effects of narrow ecological amplitude and small population size. Recent habitat fragmentation, and reductions in population size and increased isolation, is impacting on these processes, but further research is required to assess the ultimate consequences of these genetic effects for population viability.