Results are given of investigations carried out to detect any variation in the relative proportions of the several heavy minerals in heavy concentrates separated out from beach sands of the Broadbeach Recreational Area. The possible variation of the thoria content of monazite in the area is also investigated. Results indicate a systematic variation from east to west in the proportion of Zircon, rutile and ilmenite in the concentrates. The thoria content of the monazite in the area is shown to be constant within experimental limits.

The variability in the inherent optical properties along an estuary-coast-ocean continuum in tropical Australia has been studied. The study area, the Fitzroy Estuary and Keppel Bay system, is a shallow coastal environment (depth < 30 m) with highly turbid waters in the estuary and blue oceanic waters in the bay and subject to macrotides. Biogeochemical and inherent optical properties (IOPs) were sampled in the near-surface layer spatially and across the tidal phase during the dry season. These determinations included continuous measurements of spectral absorption, scattering and backscattering coefficients, together with discrete measurements of spectral absorption coefficients of phytoplankton, nonalgal particles and colored dissolved organic matter, and concentrations of phytoplankton pigments and suspended matter. Because of a large variability in the characteristics of the water components on short spatial and temporal scales, we observe a large variability in the associated optical properties. From the estuary to the bay, particle scattering and dissolved absorption decreased by 2 orders of magnitude, and nonalgal particle absorption decreased by 3 orders of magnitude. We also observed a strong variability in particle single scattering albedo and backscattering efficiency (by a factor of 6) and in specific IOPs (IOPs normalized by the relevant constituent concentration) such as suspended matter-specific particle scattering and chlorophyll-specific phytoplankton absorption. Superimposed on this strong spatial variability is the effect of the semidiurnal tide, which affects the spatial distribution of all measured properties. These results emphasize the need for spatially and temporally adjusted algorithms for remote sensing in complex coastal systems.

Beach ridges at Keppel Bay, central Queensland, Australia, preserve a record of sediment accumulation from the historical period back to middle Holocene times. The ridges comprise fine, well-sorted, feldspar-rich quartz sand that was eroded from the Fitzroy River catchment, deposited in Keppel Bay during floods of the Fitzroy River, and reworked onshore into beach and foredune deposits by the prevailing currents, waves and wind. These floods have an average recurrence interval of at least 7 yr and are induced by the passage of cyclones onshore into the large Fitzroy catchment. The youngest series of beach ridges sit sub-parallel to the modern beach and comprise six accretional units, each unit formed by a set of ridges and delineated by prominent swales. Optically stimulated luminescence (OSL) ages of beach ridges in these units indicate they were deposited in periods of rapid progradation approximately 1500, 1000, 450 and 230 yr BP, when there was an enhanced supply of sediment to the beach from the Fitzroy River via Keppel Bay. Estimates of the mass of sediment stored in the beach-ridge strandplain show that it represents a significant sediment store, potentially trapping the equivalent of 79% of the estimated long-term (100 yr) average annual bedload of the Fitzroy River that is deposited in Keppel Bay. There has been a reduction in the rate of sediment accumulation in the strandplain since around 1000 yr BP, which is consistent with other coastal records in eastern Australia of a relatively wetter phase of climate in the late Holocene compared to the present. The youngest beach ridges (OSL ages < 100 yr BP) are tall relict foredunes that reflect a low rate of sediment accumulation. These ridges have a distinctive trace-element composition produced by a greater contribution from catchment areas with basaltic soils. The change in catchment provenance has likely been a consequence of erosion that followed clearing of native vegetation in these areas. Our findings demonstrate the important insights that beach-ridge deposits proximal to a river sediment source can provide into processes of sediment accumulation and the response to variations in climate in tropical coastal sedimentary systems.

A comprehensive black and white teachers' guide reviews the history and development of the United Nation's Convention on the Law of the Sea and its application to Australian marine jurisdiction. Case studies on the North West Shelf, Antarctica and Orange Roughy are included. 108 page booklet with student activities and suggested answers. Suitable for secondary geography and science students Years 8-12.

Geoscience Australia conducted a survey of benthic nutrient fluxes in Smiths Lake , during February 2003, to gather baseline data for the ongoing management of the waterway by the Great Lakes Council. The objectives were to: 1. measure the nutrient (and other metabolite) fluxes across the sediment-water interface; 2. assess the trophic condition of the two selected sites in Smiths Lake; and 3. describe key processes controlling the nutrient fluxes across the sediment-water interface at each of the two sites. The site in the larger western basin (SL2) had a higher carbon loading than the site in the smaller eastern basin (SL1). As a result, denitrification efficiencies have been reduces and more nitrogen retained in the system. Given the long residence time of the water in Smiths Lake, there is a threat of deteriorating water quality if nutrient inputs from the catchment are increased.

Geoscience Australia is the national custodian for coastal geoscientific data and information. The organisation developed the OzCoasts web-based database and information system to draw together a diverse range of data and information on Australia's coasts and its estuaries. Previously known as OzEstuaries, the website was designed with input from over 100 scientists and resource managers from more than 50 organisations including government, universities and the National Estuaries Network. The former Coastal CRC and National Land and Water Resources Audit were instrumental in coordinating communication between the different agencies. Each month approximately 20,000 unique visitors from more than 140 countries visit the website to view around 80,000 pages. Maps, images, reports and data can be downloaded to assist with coastal science, monitoring and management. The content is arranged into six inter-linked modules: Search Data, Conceptual Models, Coastal Indicators, Habitat Mapping, Natural Resource Management, Landform and Stability Maps. More....

This report describes the investigations into the coastal creek system conducted within the Fitzroy agricultural contaminants project. Before this work started there had been only a limited data acquisition on the water quality parameters in several of the coastal creeks carried out by the Queensland Environmental Protection Agency (EPA). These data are a valuable augmentation to the data collected under Coastal CRC auspices. We briefly outline the consolidated dataset, draw qualitative conclusions from it, and develop a conceptual model reflecting the interacting processes. These analyses are then the starting point for the development of a quantitative characterisation of the role of the coastal creeks in the biogeochemistry of Keppel Bay.

The Fitzroy catchment is the largest Queensland catchment discharging to the Great Barrier Reef (GBR) lagoon. Sediments and nutrients together with anthropogenic pollutants originating upstream in the catchment are discharged from the Fitzroy River via the Fitzroy Estuary (FE) and ultimately into Keppel Bay (KB). The estuary and the bay act as natural chemical reactors where the materials delivered undergo chemical and physical transformations before some are deposited and stored in the growing deltaic and beach areas, with the remainder transported eastward to the southern zone of the GBR lagoon.

In this study of the beach-ridge plain at Keppel Bay, on the central coast of Queensland, we examine ridge morphology, sediment texture and geochemistry. We build a detailed chronology for the ridge succession using the optically stimulated luminescence (OSL) dating method. Although our interpretations are preliminary, our results suggest that significant changes have occurred in the rate of shoreline accumulation of sediment, catchment sediment source areas, and that there have been minor falls in relative sea level.

Measured probability distributions of shoreline elevation, swash height (shoreline excursion length) and swash maxima and minima from a wide range of beach types are compared to theoretical probability distributions. The theoretical distributions are based on assumptions that the time series are weakly steady-state, ergodic and a linear random process. Despite the swash process being inherently non-linear, our results indicate that these assumptions are not overly restrictive with respect to modeling exceedence statistics in the upper tail of the probability distribution. The RMS-errors for a range of exceedence level statistics (50, 10, 5, 2, and 1 percent) were restricted to <10 cm (and often <5 cm) for all of the swash variables that were investigated. The results presented here provide the basis for further refinement of coastal inundation modeling as well as stochastic-type morphodynamic modeling of beach response to waves. Further work is required, however, to relate the parameters of swash probability distributions to wave conditions further offshore.